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Wang P, Wang S, Wang D, Li Y, Yip RCS, Chen H. Postbiotics-peptidoglycan, lipoteichoic acid, exopolysaccharides, surface layer protein and pili proteins-Structure, activity in wounds and their delivery systems. Int J Biol Macromol 2024; 274:133195. [PMID: 38885869 DOI: 10.1016/j.ijbiomac.2024.133195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/06/2024] [Accepted: 06/13/2024] [Indexed: 06/20/2024]
Abstract
Chronic wound healing is a pressing global public health concern. Abuse and drug resistance of antibiotics are the key problems in the treatment of chronic wounds at present. Postbiotics are a novel promising strategy. Previous studies have reported that postbiotics have a wide range of biological activities including antimicrobial, immunomodulatory, antioxidant and anti-inflammatory abilities. However, several aspects related to these postbiotic activities remain unexplored or poorly known. Therefore, this work aims to outline general aspects and emerging trends in the use of postbiotics for wound healing, such as the production, characterization, biological activities and delivery strategies of postbiotics. In this review, a comprehensive overview of the physiological activities and structures of postbiotic biomolecules that contribute to wound healing is provided, such as peptidoglycan, lipoteichoic acid, bacteriocins, exopolysaccharides, surface layer proteins, pili proteins, and secretory proteins (p40 and p75 proteins). Considering the presence of readily degradable components in postbiotics, potential natural polymer delivery materials and delivery systems are emphasized, followed by the potential applications and commercialization prospects of postbiotics. These findings suggest that the treatment of chronic wounds with postbiotic ingredients will help provide new insights into wound healing and better guidance for the development of postbiotic products.
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Affiliation(s)
- Pu Wang
- Marine College, Shandong University, No. 180 Wen Hua West Road, Gao Strict, Weihai 264209, China.
| | - Shuxin Wang
- Marine College, Shandong University, No. 180 Wen Hua West Road, Gao Strict, Weihai 264209, China.
| | - Donghui Wang
- Marine College, Shandong University, No. 180 Wen Hua West Road, Gao Strict, Weihai 264209, China.
| | - Yuanyuan Li
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Stocking Hall, 411 Tower Road, Ithaca, NY 14853, USA.
| | - Ryan Chak Sang Yip
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord St, Toronto, ON M5S 3G5, Canada.
| | - Hao Chen
- Marine College, Shandong University, No. 180 Wen Hua West Road, Gao Strict, Weihai 264209, China.
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2
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Betts HM, Luckett JC, Hill PJ. Pilot Evaluation of S-(3-[ 18F]Fluoropropyl)-D-Homocysteine and O-(2-[ 18F]Fluoroethyl)-D-Tyrosine as Bacteria-Specific Radiotracers for PET Imaging of Infection. Mol Imaging Biol 2024; 26:704-713. [PMID: 38942967 PMCID: PMC11282134 DOI: 10.1007/s11307-024-01929-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 06/12/2024] [Accepted: 06/14/2024] [Indexed: 06/30/2024]
Abstract
PURPOSE There is currently no ideal radiotracer for imaging bacterial infections. Radiolabelled D-amino acids are promising candidates because they are actively incorporated into the peptidoglycan of the bacterial cell wall, a structural feature which is absent in human cells. This work describes fluorine-18 labelled analogues of D-tyrosine and D-methionine, O-(2-[18F]fluoroethyl)-D-tyrosine (D-[18F]FET) and S-(3-[18F]fluoropropyl)-D-homocysteine (D-[18F]FPHCys), and their pilot evaluation studies as potential radiotracers for imaging bacterial infection. PROCEDURES D-[18F]FET and D-[18F]FPHCys were prepared in classical fluorination-deprotection reactions, and their uptake in Staphylococcus aureus and Pseudomonas aeruginosa was evaluated over 2 h. Heat killed bacteria were used as controls. A clinically-relevant foreign body model of S. aureus infection was established in Balb/c mice, as well as a sterile foreign body to mimic inflammation. The ex vivo biodistribution of D-[18F]FPHCys in the infected and inflamed mice was evaluated after 1 h, by dissection and gamma counting. The uptake was compared to that of [18F]FDG. RESULTS In vitro uptake of both D-[18F]FET and D-[18F]FPHCys was specific to live bacteria. Uptake was higher in S. aureus than in P. aeruginosa for both radiotracers, and of the two, higher for D-[18F]FPHCys than D-[18F]FET. Blocking experiments with non-radioactive D-[19F]FPHCys confirmed specificity of uptake. In vivo, D-[18F]FPHCys had greater accumulation in S. aureus infection compared with sterile inflammation, which was statistically significant. As anticipated, [18F]FDG showed no significant difference in uptake between infection and inflammation. CONCLUSIONS D-[18F]FPHCys uptake was higher in infected tissues than inflammation, and represents a fluorine-18 labelled D-AA with potential to detect a S. aureus reference strain (Xen29) in vivo. Additional studies are needed to evaluate uptake of this radiotracer in clinical isolates.
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Affiliation(s)
- Helen M Betts
- Department of Nuclear Medicine, Nottingham University Hospitals NHS Trust, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
- School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
| | - Jeni C Luckett
- School of Life Sciences, University of Nottingham, Biodiscovery Institute, University Park, Nottingham, NG7 2RD, UK
| | - Philip J Hill
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, LE17 5RD, UK
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3
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Fioriti F, Rifflet A, Gomperts Boneca I, Zugasti O, Royet J. Bacterial peptidoglycan serves as a critical modulator of the gut-immune-brain axis in Drosophila. Brain Behav Immun 2024; 119:878-897. [PMID: 38710338 DOI: 10.1016/j.bbi.2024.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 04/26/2024] [Accepted: 05/03/2024] [Indexed: 05/08/2024] Open
Abstract
Metabolites and compounds derived from gut-associated bacteria can modulate numerous physiological processes in the host, including immunity and behavior. Using a model of oral bacterial infection, we previously demonstrated that gut-derived peptidoglycan (PGN), an essential constituent of the bacterial cell envelope, influences female fruit fly egg-laying behavior by activating the NF-κB cascade in a subset of brain neurons. These findings underscore PGN as a potential mediator of communication between gut bacteria and the brain in Drosophila, prompting further investigation into its impact on all brain cells. Through high-resolution mass spectrometry, we now show that PGN fragments produced by gut bacteria can rapidly reach the central nervous system. In Addition, by employing a combination of whole-genome transcriptome analyses, comprehensive genetic assays, and reporter gene systems, we reveal that gut bacterial infection triggers a PGN dose-dependent NF-κB immune response in perineurial glia, forming the continuous outer cell layer of the blood-brain barrier. Furthermore, we demonstrate that persistent PGN-dependent NF-κB activation in perineurial glial cells correlates with a reduction in lifespan and early neurological decline. Overall, our findings establish gut-derived PGN as a critical mediator of the gut-immune-brain axis in Drosophila.
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Affiliation(s)
- Florent Fioriti
- Institut de Biologie du Développement de Marseille, Aix-Marseille Université, CNRS UMR 7288 Marseille, France
| | - Aline Rifflet
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, 75015 Paris, France
| | - Ivo Gomperts Boneca
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, 75015 Paris, France
| | - Olivier Zugasti
- Institut de Biologie du Développement de Marseille, Aix-Marseille Université, CNRS UMR 7288 Marseille, France.
| | - Julien Royet
- Institut de Biologie du Développement de Marseille, Aix-Marseille Université, CNRS UMR 7288 Marseille, France.
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4
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Wang Y, Wang X, Liu X, Lin B. Research Progress on Strategies for Improving the Enzyme Properties of Bacteriophage Endolysins. J Microbiol Biotechnol 2024; 34:1189-1196. [PMID: 38693045 PMCID: PMC11239441 DOI: 10.4014/jmb.2312.12050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 05/03/2024]
Abstract
Bacterial resistance to commonly used antibiotics is one of the major challenges to be solved today. Bacteriophage endolysins (Lysins) have become a hot research topic as a new class of antibacterial agents. They have promising applications in bacterial infection prevention and control in multiple fields, such as livestock and poultry farming, food safety, clinical medicine and pathogen detection. However, many phage endolysins display low bactericidal activities, short half-life and narrow lytic spectrums. Therefore, some methods have been used to improve the enzyme properties (bactericidal activity, lysis spectrum, stability and targeting the substrate, etc) of bacteriophage endolysins, including deletion or addition of domains, DNA mutagenesis, chimerization of domains, fusion to the membrane-penetrating peptides, fusion with domains targeting outer membrane transport systems, encapsulation, the usage of outer membrane permeabilizers. In this review, research progress on the strategies for improving their enzyme properties are systematically presented, with a view to provide references for the development of lysins with excellent performances.
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Affiliation(s)
- Yulu Wang
- Shunde Women and Children's Hospital, Guangdong Medical University, Foshan 528300, P.R. China
- Dongguan Key Laboratory of Public Health Laboratory Science, School of Public Health, Guangdong Medical University, Dongguan 523808, P.R. China
| | - Xue Wang
- Dongguan Key Laboratory of Public Health Laboratory Science, School of Public Health, Guangdong Medical University, Dongguan 523808, P.R. China
| | - Xin Liu
- Dongguan Key Laboratory of Public Health Laboratory Science, School of Public Health, Guangdong Medical University, Dongguan 523808, P.R. China
| | - Bokun Lin
- Shunde Women and Children's Hospital, Guangdong Medical University, Foshan 528300, P.R. China
- Dongguan Key Laboratory of Public Health Laboratory Science, School of Public Health, Guangdong Medical University, Dongguan 523808, P.R. China
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Wang S, Huang CH, Lin TS, Yeh YQ, Fan YS, Wang SW, Tseng HC, Huang SJ, Chang YY, Jeng US, Chang CI, Tzeng SR. Structural basis for recruitment of peptidoglycan endopeptidase MepS by lipoprotein NlpI. Nat Commun 2024; 15:5461. [PMID: 38937433 PMCID: PMC11211486 DOI: 10.1038/s41467-024-49552-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 06/11/2024] [Indexed: 06/29/2024] Open
Abstract
Peptidoglycan (PG) sacculi surround the cytoplasmic membrane, maintaining cell integrity by withstanding internal turgor pressure. During cell growth, PG endopeptidases cleave the crosslinks of the fully closed sacculi, allowing for the incorporation of new glycan strands and expansion of the peptidoglycan mesh. Outer-membrane-anchored NlpI associates with hydrolases and synthases near PG synthesis complexes, facilitating spatially close PG hydrolysis. Here, we present the structure of adaptor NlpI in complex with the endopeptidase MepS, revealing atomic details of how NlpI recruits multiple MepS molecules and subsequently influences PG expansion. NlpI binding elicits a disorder-to-order transition in the intrinsically disordered N-terminal of MepS, concomitantly promoting the dimerization of monomeric MepS. This results in the alignment of two asymmetric MepS dimers respectively located on the two opposite sides of the dimerization interface of NlpI, thus enhancing MepS activity in PG hydrolysis. Notably, the protein level of MepS is primarily modulated by the tail-specific protease Prc, which is known to interact with NlpI. The structure of the Prc-NlpI-MepS complex demonstrates that NlpI brings together MepS and Prc, leading to the efficient MepS degradation by Prc. Collectively, our results provide structural insights into the NlpI-enabled avidity effect of cellular endopeptidases and NlpI-directed MepS degradation by Prc.
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Affiliation(s)
- Shen Wang
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chun-Hsiang Huang
- Protein Diffraction Group, Experimental Facility Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Te-Sheng Lin
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yi-Qi Yeh
- Soft Matter Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Yun-Sheng Fan
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Si-Wei Wang
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hsi-Ching Tseng
- Instrumentation Center, National Taiwan University, Taipei, Taiwan
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, Taipei, Taiwan
| | - Yu-Yang Chang
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - U-Ser Jeng
- Soft Matter Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Chung-I Chang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Shiou-Ru Tzeng
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.
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Watanabe N, Savchenko A. Molecular insights into the initiation step of the Rcs signaling pathway. Structure 2024:S0969-2126(24)00221-1. [PMID: 38964336 DOI: 10.1016/j.str.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/05/2024] [Accepted: 06/07/2024] [Indexed: 07/06/2024]
Abstract
The Rcs pathway is repressed by the inner membrane protein IgaA under non-stressed conditions. This repression is hypothesized to be relieved by the binding of the outer membrane-anchored RcsF to IgaA. However, the precise mechanism by which RcsF binding triggers the signaling remains unclear. Here, we present the 1.8 Å resolution crystal structure capturing the interaction between IgaA and RcsF. Our comparative structural analysis, examining both the bound and unbound states of the periplasmic domain of IgaA (IgaAp), highlights rotational flexibility within IgaAp. Conversely, the conformation of RcsF remains unchanged upon binding. Our in vivo and in vitro studies do not support the model of a stable complex involving RcsF, IgaAp, and RcsDp. Instead, we demonstrate that the elements beyond IgaAp play a role in the interaction between IgaA and RcsD. These findings collectively allow us to propose a potential mechanism for the signaling across the inner membrane through IgaA.
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Affiliation(s)
- Nobuhiko Watanabe
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada; Center for Structural Biology for Infectious Diseases (CSBID) Chicago, IL, USA
| | - Alexei Savchenko
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada; Center for Structural Biology for Infectious Diseases (CSBID) Chicago, IL, USA.
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Ojima Y, Toda K, Sawabe T, Kumazoe Y, Tahara YO, Miyata M, Azuma M. Budding and explosive membrane vesicle production by hypervesiculating Escherichia coli strain Δ rodZ. Front Microbiol 2024; 15:1400434. [PMID: 38966389 PMCID: PMC11222570 DOI: 10.3389/fmicb.2024.1400434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 06/10/2024] [Indexed: 07/06/2024] Open
Abstract
Escherichia coli produces extracellular vesicles called outer membrane vesicles. In this study, we investigated the mechanism underlying the hypervesiculation of deletion mutant ΔrodZ of E. coli. RodZ forms supramolecular complexes with actin protein MreB and peptidoglycan (PG) synthase, and plays an important role in determining the cell shape. Because mreB is an essential gene, an expression-repressed strain (mreB R3) was constructed using CRISPRi, in which the expression of mreB decreased to 20% of that in the wild-type (WT) strain. In shaken-flask culture, the ΔrodZ strain produced >50 times more vesicles than the WT strain. The mreB-repressed strain mreB R3 showed eightfold higher vesicle production than the WT. ΔrodZ and mreB R3 cells were observed using quick-freeze replica electron microscopy. As reported in previous studies, ΔrodZ cells were spherical (WT cells are rod-shaped). Some ΔrodZ cells (around 7% in total) had aberrant surface structures, such as budding vesicles and dented surfaces, or curved patterns on the surface. Holes in the PG layer and an increased cell volume were observed for ΔrodZ and mreB R3 cells compared with the WT. In conditions of osmotic support using sucrose, the OD660 value of the ΔrodZ strain increased significantly, and vesicle production decreased drastically, compared with those in the absence of sucrose. This study first clarified that vesicle production by the E. coli ΔrodZ strain is promoted by surface budding and a burst of cells that became osmotically sensitive because of their incomplete PG structure.
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Affiliation(s)
- Yoshihiro Ojima
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Kaho Toda
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Tomomi Sawabe
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Yuki Kumazoe
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Yuhei O. Tahara
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
| | - Makoto Miyata
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
| | - Masayuki Azuma
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
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Bozidis P, Markou E, Gouni A, Gartzonika K. Does Phage Therapy Need a Pan-Phage? Pathogens 2024; 13:522. [PMID: 38921819 PMCID: PMC11206709 DOI: 10.3390/pathogens13060522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 06/13/2024] [Accepted: 06/17/2024] [Indexed: 06/27/2024] Open
Abstract
The emergence of multidrug-resistant bacteria is undoubtedly one of the most serious global health threats. One response to this threat that has been gaining momentum over the past decade is 'phage therapy'. According to this, lytic bacteriophages are used for the treatment of bacterial infections, either alone or in combination with antimicrobial agents. However, to ensure the efficacy and broad applicability of phage therapy, several challenges must be overcome. These challenges encompass the development of methods and strategies for the host range manipulation and bypass of the resistance mechanisms developed by pathogenic bacteria, as has been the case since the advent of antibiotics. As our knowledge and understanding of the interactions between phages and their hosts evolves, the key issue is to define the host range for each application. In this article, we discuss the factors that affect host range and how this determines the classification of phages into different categories of action. For each host range group, recent representative examples are provided, together with suggestions on how the different groups can be used to combat certain types of bacterial infections. The available methodologies for host range expansion, either through sequential adaptation to a new pathogen or through genetic engineering techniques, are also reviewed.
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Affiliation(s)
- Petros Bozidis
- Department of Microbiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
- Department of Microbiology, University Hospital of Ioannina, 45500 Ioannina, Greece; (E.M.); (A.G.)
| | - Eleftheria Markou
- Department of Microbiology, University Hospital of Ioannina, 45500 Ioannina, Greece; (E.M.); (A.G.)
| | - Athanasia Gouni
- Department of Microbiology, University Hospital of Ioannina, 45500 Ioannina, Greece; (E.M.); (A.G.)
| | - Konstantina Gartzonika
- Department of Microbiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
- Department of Microbiology, University Hospital of Ioannina, 45500 Ioannina, Greece; (E.M.); (A.G.)
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Dorrazehi GM, Winkle M, Desmet M, Stroobant V, Tanriver G, Degand H, Evrard D, Desguin B, Morsomme P, Biboy J, Gray J, Mitusińska K, Góra A, Vollmer W, Soumillion P. PBP-A, a cyanobacterial DD-peptidase with high specificity for amidated muropeptides, exhibits pH-dependent promiscuous activity harmful to Escherichia coli. Sci Rep 2024; 14:13999. [PMID: 38890528 PMCID: PMC11189452 DOI: 10.1038/s41598-024-64806-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 06/13/2024] [Indexed: 06/20/2024] Open
Abstract
Penicillin binding proteins (PBPs) are involved in biosynthesis, remodeling and recycling of peptidoglycan (PG) in bacteria. PBP-A from Thermosynechococcus elongatus belongs to a cyanobacterial family of enzymes sharing close structural and phylogenetic proximity to class A β-lactamases. With the long-term aim of converting PBP-A into a β-lactamase by directed evolution, we simulated what may happen when an organism like Escherichia coli acquires such a new PBP and observed growth defect associated with the enzyme activity. To further explore the molecular origins of this harmful effect, we decided to characterize deeper the activity of PBP-A both in vitro and in vivo. We found that PBP-A is an enzyme endowed with DD-carboxypeptidase and DD-endopeptidase activities, featuring high specificity towards muropeptides amidated on the D-iso-glutamyl residue. We also show that a low promiscuous activity on non-amidated peptidoglycan deteriorates E. coli's envelope, which is much higher under acidic conditions where substrate discrimination is mitigated. Besides expanding our knowledge of the biochemical activity of PBP-A, this work also highlights that promiscuity may depend on environmental conditions and how it may hinder rather than promote enzyme evolution in nature or in the laboratory.
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Affiliation(s)
- Gol Mohammad Dorrazehi
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Place Croix du Sud 4-5, 1348, Louvain-la-Neuve, Belgium
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Matthias Winkle
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
- Benchmark Animal Health Ltd, 1 Pioneer Building, Edinburgh Technopole, Milton Bridge, Penicuik, EH26 0GB, UK
| | - Martin Desmet
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Place Croix du Sud 4-5, 1348, Louvain-la-Neuve, Belgium
| | - Vincent Stroobant
- Ludwig Institute for Cancer Research, Brussels, Belgium
- de Duve Institute, UCLouvain, Brussels, Belgium
| | - Gamze Tanriver
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, 44-100, Gliwice, Poland
| | - Hervé Degand
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Place Croix du Sud 4-5, 1348, Louvain-la-Neuve, Belgium
| | - Damien Evrard
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Place Croix du Sud 4-5, 1348, Louvain-la-Neuve, Belgium
| | - Benoît Desguin
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Place Croix du Sud 4-5, 1348, Louvain-la-Neuve, Belgium
| | - Pierre Morsomme
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Place Croix du Sud 4-5, 1348, Louvain-la-Neuve, Belgium
| | - Jacob Biboy
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Joe Gray
- Biosciences Institute, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Karolina Mitusińska
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, 44-100, Gliwice, Poland
| | - Artur Góra
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, 44-100, Gliwice, Poland
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Patrice Soumillion
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Place Croix du Sud 4-5, 1348, Louvain-la-Neuve, Belgium.
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10
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Xu Q, Tang L, Liu W, Xu N, Hu Y, Zhang Y, Chen S. Phage protein Gp11 blocks Staphylococcus aureus cell division by inhibiting peptidoglycan biosynthesis. mBio 2024; 15:e0067924. [PMID: 38752726 PMCID: PMC11237401 DOI: 10.1128/mbio.00679-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 04/10/2024] [Indexed: 06/13/2024] Open
Abstract
Phages and bacteria have a long history of co-evolution. However, these dynamics of phage-host interactions are still largely unknown; identification of phage inhibitors that remodel host metabolism will provide valuable information for target development for antimicrobials. Here, we perform a comprehensive screen for early-gene products of ΦNM1 that inhibit cell growth in Staphylococcus aureus. A small membrane protein, Gp11, with inhibitory effects on S. aureus cell division was identified. A bacterial two-hybrid library containing 345 essential S. aureus genes was constructed to screen for targets of Gp11, and Gp11 was found to interact with MurG and DivIC. Defects in cell growth and division caused by Gp11 were dependent on MurG and DivIC, which was further confirmed using CRISPRi hypersensitivity assay. Gp11 interacts with MurG, the protein essential for cell wall formation, by inhibiting the production of lipid II to regulate peptidoglycan (PG) biosynthesis on the cell membrane. Gp11 also interacts with cell division protein DivIC, an essential part of the division machinery necessary for septal cell wall assembly, to disrupt the recruitment of division protein FtsW. Mutations in Gp11 result in loss of its ability to cause growth defects, whereas infection with phage in which the gp11 gene has been deleted showed a significant increase in lipid II production in S. aureus. Together, our findings reveal that a phage early-gene product interacts with essential host proteins to disrupt PG biosynthesis and block S. aureus cell division, suggesting a potential pathway for the development of therapeutic approaches to treat pathogenic bacterial infections. IMPORTANCE Understanding the interplay between phages and their hosts is important for the development of novel therapies against pathogenic bacteria. Although phages have been used to control methicillin-resistant Staphylococcus aureus infections, our knowledge related to the processes in the early stages of phage infection is still limited. Owing to the fact that most of the phage early proteins have been classified as hypothetical proteins with uncertain functions, we screened phage early-gene products that inhibit cell growth in S. aureus, and one protein, Gp11, selectively targets essential host genes to block the synthesis of the peptidoglycan component lipid II, ultimately leading to cell growth arrest in S. aureus. Our study provides a novel insight into the strategy by which Gp11 blocks essential host cellular metabolism to influence phage-host interaction. Importantly, dissecting the interactions between phages and host cells will contribute to the development of new and effective therapies to treat bacterial infections.
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Affiliation(s)
- Qi Xu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Li Tang
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Weilin Liu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Neng Xu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Yangbo Hu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Yong Zhang
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Shiyun Chen
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
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11
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Alcorlo M, Martínez-Caballero S, Li J, Sham LT, Luo M, Hermoso JA. Modulation of the lytic apparatus by the FtsEX complex within the bacterial division machinery. FEBS Lett 2024. [PMID: 38849310 DOI: 10.1002/1873-3468.14953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/09/2024]
Abstract
The FtsEX membrane complex constitutes an essential component of the ABC transporter superfamily, widely distributed among bacterial species. It governs peptidoglycan degradation for cell division, acting as a signal transmitter rather than a substrate transporter. Through the ATPase activity of FtsE, it facilitates signal transmission from the cytosol across the membrane to the periplasm, activating associated peptidoglycan hydrolases. This review concentrates on the latest structural advancements elucidating the architecture of the FtsEX complex and its interplay with lytic enzymes or regulatory counterparts. The revealed three-dimensional structures unveil a landscape wherein a precise array of intermolecular interactions, preserved across diverse bacterial species, afford meticulous spatial and temporal control over the cell division process.
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Affiliation(s)
- Martín Alcorlo
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Siseth Martínez-Caballero
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Jianwei Li
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Department of Biological Sciences, Center for Bioimaging Sciences, National University of Singapore, Singapore
| | - Lok-To Sham
- Infectious Diseases Translational Research Programme and Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Min Luo
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Department of Biological Sciences, Center for Bioimaging Sciences, National University of Singapore, Singapore
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
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12
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Ryoo D, Hwang H, Gumbart JC. Thicket and Mesh: How the Outer Membrane Can Resist Tension Imposed by the Cell Wall. J Phys Chem B 2024; 128:5371-5377. [PMID: 38787347 PMCID: PMC11163421 DOI: 10.1021/acs.jpcb.3c08510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 05/07/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024]
Abstract
The cell envelope of Gram-negative bacteria is composed of an outer membrane (OM) and an inner membrane (IM) and a peptidoglycan cell wall (CW) between them. Combined with Braun's lipoprotein (Lpp), which connects the OM and the CW, and numerous membrane proteins that exist in both OM and IM, the cell envelope creates a mechanically stable environment that resists various physical and chemical perturbations to the cell, including turgor pressure caused by the solute concentration difference between the cytoplasm of the cell and the extracellular environment. Previous computational studies have explored how individual components (OM, IM, and CW) can resist turgor pressure although combinations of them have been less well studied. To that end, we constructed multiple OM-CW systems, including the Lpp connections with the CW under increasing degrees of strain. The results show that the OM can effectively resist the tension imposed by the CW, shrinking by only 3-5% in area even when the CW is stretched to 2.5× its relaxed area. The area expansion modulus of the system increases with increasing CW strain, although the OM remains a significant contributor to the envelope's mechanical stability. Additionally, we find that when the protein TolC is embedded in the OM, its stiffness increases.
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Affiliation(s)
- David Ryoo
- Interdisciplinary
Bioengineering Graduate Program, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Hyea Hwang
- School
of Materials Science and Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - James C. Gumbart
- School
of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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13
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Mishra N, Gutheil WG. Stereoselective Amine-omics Using Heavy Atom Isotope Labeled l- and d-Marfey's Reagents. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1217-1226. [PMID: 38683793 PMCID: PMC11160435 DOI: 10.1021/jasms.4c00036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/20/2024] [Accepted: 04/05/2024] [Indexed: 05/02/2024]
Abstract
Biological amines and amino acids play essential roles in many biochemical processes. The chemical complexity of biological samples is challenging, and the selective identification and quantification of amines and amino acid stereoisomers would be very useful for amine-focused "amino-omics" studies. Many amines and amino acids are chiral, and their stereoisomers cannot be resolved on achiral media without chiral derivatization. In prior studies, we demonstrated the use of Marfey's reagent─a chiral derivatization reagent for amines and phenolic OH groups─for the LC-MS/MS resolution and quantification of amines and amino acid stereoisomers. In this study, a heavy atom isotope labeled Marfey's reagent approach for the stereoselective detection and quantification of amines and amino acids was developed. Heavy (13C2) l-Marfey's (Hl-Mar) and heavy (2H3) d-Marfey's (Hd-Mar) were synthesized from 13C2-l-Ala and 2H3-d-Ala, respectively. Both light and heavy Marfey's reagents were used to derivatize standard amine mixtures, which were analyzed by LC-QToF-HRMS. Aligned peak lists were comparatively analyzed by light vs heavy Mar mass differences to identify mono-, di-, and tri-Marfey's adducts and then by the retention time difference between l- and d-Mar derivatives to identify stereoisomers. This approach was then applied to identify achiral and chiral amine and amino acid components in a methicillin-resistant Staphylococcus aureus (MRSA) extract. This approach shows high analytical selectivity and reproducibility.
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Affiliation(s)
- Nitish
R. Mishra
- Division of Pharmacology
and Pharmaceutical Sciences, School of Pharmacy, University of Missouri—Kansas City, Kansas City, Missouri 64108, United States
| | - William G. Gutheil
- Division of Pharmacology
and Pharmaceutical Sciences, School of Pharmacy, University of Missouri—Kansas City, Kansas City, Missouri 64108, United States
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14
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Mitkowski P, Jagielska E, Sabała I. Engineering of chimeric enzymes with expanded tolerance to ionic strength. Microbiol Spectr 2024; 12:e0354623. [PMID: 38695664 DOI: 10.1128/spectrum.03546-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 03/26/2024] [Indexed: 06/06/2024] Open
Abstract
Antimicrobial resistance poses a significant global threat, reaching dangerously high levels as reported by the World Health Organization. The emergence and rapid spread of new resistance mechanisms, coupled with the absence of effective treatments in recent decades, have led to thousands of deaths annually from infections caused by drug-resistant microorganisms. Consequently, there is an urgent need for the development of new compounds capable of combating antibiotic-resistant bacteria. A promising class of molecules exhibiting potent bactericidal effects is peptidoglycan hydrolases. Previously, we cloned and characterized the biochemical properties of the M23 catalytic domain of the EnpA (EnpACD) protein from Enterococcus faecalis. Unlike other enzymes within the M23 family, EnpACD demonstrates broad specificity. However, its activity is constrained under low ionic strength conditions. In this study, we present the engineering of three chimeric enzymes comprising EnpACD fused with three distinct SH3b cell wall-binding domains. These chimeras exhibit enhanced tolerance to environmental conditions and sustained activity in bovine and human serum. Furthermore, our findings demonstrate that the addition of SH3b domains influences the activity of the chimeric enzymes, thereby expanding their potential applications in combating antimicrobial resistance.IMPORTANCEThese studies demonstrate that the addition of the SH3b-binding domain to the EnpACD results in generation of chimeras with a broader tolerance to ionic strength and pH values, enabling them to remain active over a wider range of conditions. Such approach offers a relatively straightforward method for obtaining antibacterial enzymes with tailored properties and emphasizes the potential for proteins' engineering with enhanced functionality, contributing to the ongoing efforts to address antimicrobial resistance effectively.
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Affiliation(s)
- Paweł Mitkowski
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - Elżbieta Jagielska
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - Izabela Sabała
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
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15
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Javid M, Shahverdi AR, Ghasemi A, Moosavi-Movahedi AA, Ebrahim-Habibi A, Sepehrizadeh Z. Decoding the Structure-Function Relationship of the Muramidase Domain in E. coli O157.H7 Bacteriophage Endolysin: A Potential Building Block for Chimeric Enzybiotics. Protein J 2024; 43:522-543. [PMID: 38662183 DOI: 10.1007/s10930-024-10195-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2024] [Indexed: 04/26/2024]
Abstract
Bacteriophage endolysins are potential alternatives to conventional antibiotics for treating multidrug-resistant gram-negative bacterial infections. However, their structure-function relationships are poorly understood, hindering their optimization and application. In this study, we focused on the individual functionality of the C-terminal muramidase domain of Gp127, a modular endolysin from E. coli O157:H7 bacteriophage PhaxI. This domain is responsible for the enzymatic activity, whereas the N-terminal domain binds to the bacterial cell wall. Through protein modeling, docking experiments, and molecular dynamics simulations, we investigated the activity, stability, and interactions of the isolated C-terminal domain with its ligand. We also assessed its expression, solubility, toxicity, and lytic activity using the experimental data. Our results revealed that the C-terminal domain exhibits high activity and toxicity when tested individually, and its expression is regulated in different hosts to prevent self-destruction. Furthermore, we validated the muralytic activity of the purified refolded protein by zymography and standardized assays. These findings challenge the need for the N-terminal binding domain to arrange the active site and adjust the gap between crucial residues for peptidoglycan cleavage. Our study shed light on the three-dimensional structure and functionality of muramidase endolysins, thereby enriching the existing knowledge pool and laying a foundation for accurate in silico modeling and the informed design of next-generation enzybiotic treatments.
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Affiliation(s)
- Mehri Javid
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy & Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Shahverdi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy & Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Atiyeh Ghasemi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | | | - Azadeh Ebrahim-Habibi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy & Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
- Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
| | - Zargham Sepehrizadeh
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy & Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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16
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Carratalá JV, Ferrer-Miralles N, Garcia-Fruitós E, Arís A. LysJEP8: A promising novel endolysin for combating multidrug-resistant Gram-negative bacteria. Microb Biotechnol 2024; 17:e14483. [PMID: 38864495 PMCID: PMC11167605 DOI: 10.1111/1751-7915.14483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 05/03/2024] [Accepted: 05/08/2024] [Indexed: 06/13/2024] Open
Abstract
Antimicrobial resistance (AMR) is an escalating global health crisis, driven by the overuse and misuse of antibiotics. Multidrug-resistant Gram-negative bacteria, such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae, are particularly concerning due to their high morbidity and mortality rates. In this context, endolysins, derived from bacteriophages, offer a promising alternative to traditional antibiotics. This study introduces LysJEP8, a novel endolysin derived from Escherichia phage JEP8, which exhibits remarkable antimicrobial activity against key Gram-negative members of the ESKAPE group. Comparative assessments highlight LysJEP8's superior performance in reducing bacterial survival rates compared to previously described endolysins, with the most significant impact observed against P. aeruginosa, and notable effects on A. baumannii and K. pneumoniae. The study found that LysJEP8, as predicted by in silico analysis, worked best at lower pH values but lost its effectiveness at salt concentrations close to physiological levels. Importantly, LysJEP8 exhibited remarkable efficacy in the disruption of P. aeruginosa biofilms. This research underscores the potential of LysJEP8 as a valuable candidate for the development of innovative antibacterial agents, particularly against Gram-negative pathogens, and highlights opportunities for further engineering and optimization to address AMR effectively.
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Affiliation(s)
- Jose Vicente Carratalá
- Institute of Biotechnology and Biomedicine, Autonomous University of Barcelona, Barcelona, Spain
- Department of Genetics and Microbiology, Autonomous University of Barcelona, Barcelona, Spain
- Department of Ruminant Production, Institute of Agriculture and Agrifood Research and Technology (IRTA), Barcelona, Spain
- Bioengineering, Biomaterials and Nanomedicine Networking Biomedical Research Centre (CIBER-BBN), Madrid, Spain
| | - Neus Ferrer-Miralles
- Institute of Biotechnology and Biomedicine, Autonomous University of Barcelona, Barcelona, Spain
- Department of Genetics and Microbiology, Autonomous University of Barcelona, Barcelona, Spain
- Bioengineering, Biomaterials and Nanomedicine Networking Biomedical Research Centre (CIBER-BBN), Madrid, Spain
| | - Elena Garcia-Fruitós
- Department of Ruminant Production, Institute of Agriculture and Agrifood Research and Technology (IRTA), Barcelona, Spain
| | - Anna Arís
- Department of Ruminant Production, Institute of Agriculture and Agrifood Research and Technology (IRTA), Barcelona, Spain
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17
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Yang L, Lawhorn S, Bongrand C, Kosmopoulos JC, Kuwabara J, VanNieuwenhze M, Mandel MJ, McFall-Ngai M, Ruby E. Bacterial growth dynamics in a rhythmic symbiosis. Mol Biol Cell 2024; 35:ar79. [PMID: 38598294 PMCID: PMC11238090 DOI: 10.1091/mbc.e24-01-0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/01/2024] [Accepted: 04/04/2024] [Indexed: 04/12/2024] Open
Abstract
The symbiotic relationship between the bioluminescent bacterium Vibrio fischeri and the bobtail squid Euprymna scolopes serves as a valuable system to investigate bacterial growth and peptidoglycan (PG) synthesis within animal tissues. To better understand the growth dynamics of V. fischeri in the crypts of the light-emitting organ of its juvenile host, we showed that, after the daily dawn-triggered expulsion of most of the population, the remaining symbionts rapidly proliferate for ∼6 h. At that point the population enters a period of extremely slow growth that continues throughout the night until the next dawn. Further, we found that PG synthesis by the symbionts decreases as they enter the slow-growing stage. Surprisingly, in contrast to the most mature crypts (i.e., Crypt 1) of juvenile animals, most of the symbiont cells in the least mature crypts (i.e., Crypt 3) were not expelled and, instead, remained in the slow-growing state throughout the day, with almost no cell division. Consistent with this observation, the expression of the gene encoding the PG-remodeling enzyme, L,D-transpeptidase (LdtA), was greatest during the slowly growing stage of Crypt 1 but, in contrast, remained continuously high in Crypt 3. Finally, deletion of the ldtA gene resulted in a symbiont that grew and survived normally in culture, but was increasingly defective in competing against its parent strain in the crypts. This result suggests that remodeling of the PG to generate additional 3-3 linkages contributes to the bacterium's fitness in the symbiosis, possibly in response to stresses encountered during the very slow-growing stage.
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Affiliation(s)
- Liu Yang
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - Susannah Lawhorn
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - Clotilde Bongrand
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - James C. Kosmopoulos
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Jill Kuwabara
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | | | - Mark J. Mandel
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI 53706
| | - Margaret McFall-Ngai
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Edward Ruby
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125
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18
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Muhamad Hendri NA, Nor Amdan NA, Dounis SO, Sulaiman Najib N, Louis SR. Ultrastructural and morphological studies on variables affecting Escherichia coli with selected commercial antibiotics. Cell Surf 2024; 11:100120. [PMID: 38313869 PMCID: PMC10831149 DOI: 10.1016/j.tcsw.2024.100120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 02/06/2024] Open
Abstract
Background Many studies reported the effects of antibiotic exposure on E. coli bacterial growth and cell modification. However, scarce descriptive information on ultrastructural effects upon exposure of commercial antibiotics. Methods This study described the morphological and ultrastructural alterations caused by selected antibiotics (amoxicillin-clavulanate, ceftriaxone, polymyxin B, colistin, gentamicin, and amikacin) that targeted cell wall, plasma membrane, and cytoplasmic density, and also proteins synthesis. We determined extracellular morphological changes of exposure through scanning electron microscopy (FESEM) and intracellular activities through transmission electron microscopy (TEM) investigation. Results FESEM and TEM micrograph of E. coli exposed with selected antibiotics shows ultrastructural changes in beta-lactam class (amoxicillin-clavulanate, ceftriaxone) elongated the cells as the cell wall was altered as it inhibits bacterial cell wall synthesis, polymyxin class (polymyxin B, colistin) had plasmid and curli-fimbriae as it breaking down the plasma/cytoplasmic membrane, and aminoglycoside class (gentamicin, and amikacin) reduced ribosome concentration as it inhibits bacterial protein synthesis by binding to 30 s ribosomes. Conclusion Morphological and ultrastructural alterations of E. coli's mechanism of actions were translated and depicted. This study could be reference for characterization studies for morphological and ultrastructural of E. coli upon exposure to antimicrobial agents.
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Affiliation(s)
- Nur Afrina Muhamad Hendri
- Electron Microscopy Unit, Special Resource Centre (SRC), Institute for Medical Research, Ministry of Health Malaysia, Setia Alam, 40170 Selangor, Malaysia
| | - Nur Asyura Nor Amdan
- Bacteriology Unit, Infectious Disease Research Centre (IDRC), Institute for Medical Research, Ministry of Health Malaysia, Setia Alam, 40170 Selangor, Malaysia
| | - Shelly Olevia Dounis
- Electron Microscopy Unit, Special Resource Centre (SRC), Institute for Medical Research, Ministry of Health Malaysia, Setia Alam, 40170 Selangor, Malaysia
| | - Norzarila Sulaiman Najib
- Electron Microscopy Unit, Special Resource Centre (SRC), Institute for Medical Research, Ministry of Health Malaysia, Setia Alam, 40170 Selangor, Malaysia
| | - Santhana Raj Louis
- Electron Microscopy Unit, Special Resource Centre (SRC), Institute for Medical Research, Ministry of Health Malaysia, Setia Alam, 40170 Selangor, Malaysia
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19
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BELITSKY BORISR. Histidine kinase-mediated cross-regulation of the vancomycin-resistance operon in Clostridioides difficile. Mol Microbiol 2024; 121:1182-1199. [PMID: 38690761 PMCID: PMC11176017 DOI: 10.1111/mmi.15273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/03/2024] [Accepted: 04/17/2024] [Indexed: 05/03/2024]
Abstract
The dipeptide D-Ala-D-Ala is an essential component of peptidoglycan and the target of vancomycin. Most Clostridioides difficile strains possess the vanG operon responsible for the synthesis of D-Ala-D-Ser, which can replace D-Ala-D-Ala in peptidoglycan. The C. difficile vanG operon is regulated by a two-component system, VanRS, but is not induced sufficiently by vancomycin to confer resistance to this antibiotic. Surprisingly, in the absence of the VanS histidine kinase (HK), the vanG operon is still induced by vancomycin and also by another antibiotic, ramoplanin, in a VanR-dependent manner. This suggested the cross-regulation of VanR by another HK or kinases that are activated in the presence of certain lipid II-targeting antibiotics. We identified these HKs as CD35990 and CD22880. However, mutations in either or both HKs did not affect the regulation of the vanG operon in wild-type cells suggesting that intact VanS prevents the cross-activation of VanR by non-cognate HKs. Overproduction of VanR in the absence of VanS, CD35990, and CD22880 led to high expression of the vanG operon indicating that VanR can potentially utilize at least one more phosphate donor for its activation. Candidate targets of CD35990- and CD22880-mediated regulation in the presence of vancomycin or ramoplanin were identified by RNA-Seq.
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Affiliation(s)
- BORIS R. BELITSKY
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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20
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Bon CG, Grigg JC, Lee J, Robb CS, Caveney NA, Eltis LD, Strynadka NCJ. Structural and kinetic analysis of the monofunctional Staphylococcus aureus PBP1. J Struct Biol 2024; 216:108086. [PMID: 38527711 DOI: 10.1016/j.jsb.2024.108086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 03/27/2024]
Abstract
Staphylococcus aureus, an ESKAPE pathogen, is a major clinical concern due to its pathogenicity and manifold antimicrobial resistance mechanisms. The commonly used β-lactam antibiotics target bacterial penicillin-binding proteins (PBPs) and inhibit crosslinking of peptidoglycan strands that comprise the bacterial cell wall mesh, initiating a cascade of effects leading to bacterial cell death. S. aureus PBP1 is involved in synthesis of the bacterial cell wall during division and its presence is essential for survival of both antibiotic susceptible and resistant S. aureus strains. Here, we present X-ray crystallographic data for S. aureus PBP1 in its apo form as well as acyl-enzyme structures with distinct classes of β-lactam antibiotics representing the penicillins, carbapenems, and cephalosporins, respectively: oxacillin, ertapenem and cephalexin. Our structural data suggest that the PBP1 active site is readily accessible for substrate, with little conformational change in key structural elements required for its covalent acylation of β-lactam inhibitors. Stopped-flow kinetic analysis and gel-based competition assays support the structural observations, with even the weakest performing β-lactams still having comparatively high acylation rates and affinities for PBP1. Our structural and kinetic analysis sheds insight into the ligand-PBP interactions that drive antibiotic efficacy against these historically useful antimicrobial targets and expands on current knowledge for future drug design and treatment of S. aureus infections.
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Affiliation(s)
- Christopher G Bon
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jason C Grigg
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jaeyong Lee
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Craig S Robb
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Nathanael A Caveney
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Lindsay D Eltis
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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21
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Newstead S, Parker J, Deme J, Lichtinger S, Kuteyi G, Biggin P, Lea S. Structural basis for antibiotic transport and inhibition in PepT2, the mammalian proton-coupled peptide transporter. RESEARCH SQUARE 2024:rs.3.rs-4435259. [PMID: 38903084 PMCID: PMC11188089 DOI: 10.21203/rs.3.rs-4435259/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The uptake and elimination of beta-lactam antibiotics in the human body are facilitated by the proton-coupled peptide transporters PepT1 (SLC15A1) and PepT2 (SLC15A2). The mechanism by which SLC15 family transporters recognize and discriminate between different drug classes and dietary peptides remains unclear, hampering efforts to improve antibiotic pharmacokinetics through targeted drug design and delivery. Here, we present cryo-EM structures of the mammalian proton-coupled peptide transporter, PepT2, in complex with the widely used beta-lactam antibiotics cefadroxil, amoxicillin and cloxacillin. Our structures, combined with pharmacophore mapping, molecular dynamics simulations and biochemical assays, establish the mechanism of antibiotic recognition and the important role of protonation in drug binding and transport.
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Affiliation(s)
| | | | - Justin Deme
- National Cancer Institute, National Institutes of Health
| | | | | | | | - Susan Lea
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute
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22
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Choi HJ, Ki DU, Yoon SI. Structural and biochemical analysis of penicillin-binding protein 2 from Campylobacter jejuni. Biochem Biophys Res Commun 2024; 710:149859. [PMID: 38581948 DOI: 10.1016/j.bbrc.2024.149859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 03/27/2024] [Indexed: 04/08/2024]
Abstract
Penicillin-binding protein 2 (PBP2) plays a key role in the formation of peptidoglycans in bacterial cell walls by crosslinking glycan chains through transpeptidase activity. PBP2 is also found in Campylobacter jejuni, a pathogenic bacterium that causes food-borne enteritis in humans. To elucidate the essential structural features of C. jejuni PBP2 (cjPBP2) that mediate its biological function, we determined the crystal structure of cjPBP2 and assessed its protein stability under various conditions. cjPBP2 adopts an elongated two-domain structure, consisting of a transpeptidase domain and a pedestal domain, and contains typical active site residues necessary for transpeptidase activity, as observed in other PBP2 proteins. Moreover, cjPBP2 responds to β-lactam antibiotics, including ampicillin, cefaclor, and cefmetazole, suggesting that β-lactam antibiotics inactivate cjPBP2. In contrast to typical PBP2 proteins, cjPBP2 is a rare example of a Zn2+-binding PBP2 protein, as the terminal structure of its transpeptidase domain accommodates a Zn2+ ion via three cysteine residues and one histidine residue. Zn2+ binding helps improve the protein stability of cjPBP2, providing opportunities to develop new C. jejuni-specific antibacterial drugs that counteract the Zn2+-binding ability of cjPBP2.
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Affiliation(s)
- Hong Joon Choi
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Dong Uk Ki
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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23
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Miyamoto T. Multifunctional enzymes related to amino acid metabolism in bacteria. Biosci Biotechnol Biochem 2024; 88:585-593. [PMID: 38439669 DOI: 10.1093/bbb/zbae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 02/29/2024] [Indexed: 03/06/2024]
Abstract
In bacteria, d-amino acids are primarily synthesized from l-amino acids by amino acid racemases, but some bacteria use d-amino acid aminotransferases to synthesize d-amino acids. d-Amino acids are peptidoglycan components in the cell wall involved in several physiological processes, such as bacterial growth, biofilm dispersal, and peptidoglycan metabolism. Therefore, their metabolism and physiological roles have attracted increasing attention. Recently, we identified novel bacterial d-amino acid metabolic pathways, which involve amino acid racemases, with broad substrate specificity, as well as multifunctional enzymes with d-amino acid-metabolizing activity. Here, I review these multifunctional enzymes and their related d- and l-amino acid metabolic pathways in Escherichia coli and the hyperthermophile Thermotoga maritima.
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Affiliation(s)
- Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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24
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Shen H, Zhang C, Li S, Liang Y, Lee LT, Aggarwal N, Wun KS, Liu J, Nadarajan SP, Weng C, Ling H, Tay JK, Wang DY, Yao SQ, Hwang IY, Lee YS, Chang MW. Prodrug-conjugated tumor-seeking commensals for targeted cancer therapy. Nat Commun 2024; 15:4343. [PMID: 38773197 PMCID: PMC11109227 DOI: 10.1038/s41467-024-48661-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 05/08/2024] [Indexed: 05/23/2024] Open
Abstract
Prodrugs have been explored as an alternative to conventional chemotherapy; however, their target specificity remains limited. The tumor microenvironment harbors a range of microorganisms that potentially serve as tumor-targeting vectors for delivering prodrugs. In this study, we harness bacteria-cancer interactions native to the tumor microbiome to achieve high target specificity for prodrug delivery. We identify an oral commensal strain of Lactobacillus plantarum with an intrinsic cancer-binding mechanism and engineer the strain to enable the surface loading of anticancer prodrugs, with nasopharyngeal carcinoma (NPC) as a model cancer. The engineered commensals show specific binding to NPC via OppA-mediated recognition of surface heparan sulfate, and the loaded prodrugs are activated by tumor-associated biosignals to release SN-38, a chemotherapy compound, near NPC. In vitro experiments demonstrate that the prodrug-loaded microbes significantly increase the potency of SN-38 against NPC cell lines, up to 10-fold. In a mouse xenograft model, intravenous injection of the engineered L. plantarum leads to bacterial colonization in NPC tumors and a 67% inhibition in tumor growth, enhancing the efficacy of SN-38 by 54%.
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Affiliation(s)
- Haosheng Shen
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- National Centre for Engineering Biology (NCEB), Singapore, Singapore
| | - Changyu Zhang
- Ningbo Institute of Dalian University of Technology, Ningbo, China
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Shengjie Li
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Institute of Translational Medicine, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Yuanmei Liang
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- National Centre for Engineering Biology (NCEB), Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Li Ting Lee
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- National Centre for Engineering Biology (NCEB), Singapore, Singapore
| | - Nikhil Aggarwal
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- National Centre for Engineering Biology (NCEB), Singapore, Singapore
| | - Kwok Soon Wun
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- National Centre for Engineering Biology (NCEB), Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jing Liu
- Department of Otolaryngology, Infectious Diseases Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Saravanan Prabhu Nadarajan
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Cheng Weng
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Hua Ling
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Wilmar International Limited, Singapore, Singapore
| | - Joshua K Tay
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Otolaryngology-Head and Neck Surgery, National University of Singapore, Singapore, Singapore
| | - De Yun Wang
- Department of Otolaryngology, Infectious Diseases Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Shao Q Yao
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - In Young Hwang
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore.
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- Food, Chemical and Biotechnology, Singapore Institute of Technology, Singapore, Singapore.
| | - Yung Seng Lee
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Matthew Wook Chang
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore.
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- National Centre for Engineering Biology (NCEB), Singapore, Singapore.
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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25
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Rajguru V, Chatterjee S, Garde S, Reddy M. Crosslink cleaving enzymes: the smart autolysins that remodel the bacterial cell wall. Trends Microbiol 2024; 32:494-506. [PMID: 38072724 DOI: 10.1016/j.tim.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 05/12/2024]
Abstract
Peptidoglycan (PG) is a protective mesh-like polymer in bacterial cell walls that enables their survival in almost every ecological niche. PG is formed by crosslinking of several glycan strands through short peptides, conferring a characteristic structure and elasticity, distinguishing it from other polymeric exoskeletons. The significance of PG crosslink formation has been known for decades, as some of the most widely used antibiotics, namely β-lactams, target the enzymes that catalyze this step. However, the importance of crosslink hydrolysis in PG biology remained largely underappreciated. Recent advances demonstrate the functions of crosslink cleavage in diverse physiological processes, including an indispensable role in PG expansion during the cell cycle, thereby making crosslink cleaving enzymes an untapped target for novel drugs. Here, we elaborate on the fundamental roles of crosslink-specific endopeptidases and their regulation across the bacterial kingdom.
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Affiliation(s)
- Vaidehi Rajguru
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, 500007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Stuti Chatterjee
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, 500007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Shambhavi Garde
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, 500007, India
| | - Manjula Reddy
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, 500007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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26
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Miguel-Ruano V, Feltzer R, Batuecas MT, Ramachandran B, El-Araby AM, Avila-Cobian LF, De Benedetti S, Mobashery S, Hermoso JA. Structural characterization of lytic transglycosylase MltD of Pseudomonas aeruginosa, a target for the natural product bulgecin A. Int J Biol Macromol 2024; 267:131420. [PMID: 38583835 DOI: 10.1016/j.ijbiomac.2024.131420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 04/01/2024] [Accepted: 04/04/2024] [Indexed: 04/09/2024]
Abstract
Natural product bulgecin A potentiates the activity of β-lactam antibiotics by inhibition of three lytic transglycosylases in Pseudomonas aeruginosa, of which MltD is one. MltD exhibits both endolytic and exolytic reactions in the turnover of the cell-wall peptidoglycan and tolerates the presence or absence of stem peptides in its substrates. The present study reveals structural features of the multimodular MltD, presenting a catalytic module and four cell-wall-binding LysM modules that account for these attributes. Three X-ray structures are reported herein for MltD that disclose one unpredicted LysM module tightly attached to the catalytic domain, whereas the other LysM modules are mobile, and connected to the catalytic domain through long flexible linkers. The formation of crystals depended on the presence of bulgecin A. The expansive active-site cleft is highlighted by the insertion of a helical region, a hallmark of the family 1D of lytic transglycosylases, which was mapped out in a ternary complex of MltD:bulgecinA:chitotetraose, revealing at the minimum the presence of eight subsites (from -4 to +4, with the seat of reaction at subsites -1 and + 1) for binding of sugars of the substrate for the endolytic reaction. The mechanism of the exolytic reaction is revealed in one of the structures, showing how the substrate's terminal anhydro-NAM moiety could be sequestered at subsite +2. Our results provide the structural insight for both the endolytic and exolytic activities of MltD during cell-wall-turnover events.
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Affiliation(s)
- Vega Miguel-Ruano
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Rhona Feltzer
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - María T Batuecas
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Balajee Ramachandran
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Amr M El-Araby
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Luis F Avila-Cobian
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Stefania De Benedetti
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain.
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27
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Arora K, Sherilraj PM, Abutwaibe KA, Dhruw B, Mudavath SL. Exploring glycans as vital biological macromolecules: A comprehensive review of advancements in biomedical frontiers. Int J Biol Macromol 2024; 268:131511. [PMID: 38615867 DOI: 10.1016/j.ijbiomac.2024.131511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 04/02/2024] [Accepted: 04/09/2024] [Indexed: 04/16/2024]
Abstract
This comprehensive review delves into the intricate landscape of glycans and glycoconjugates, unraveling their multifaceted roles across diverse biological dimensions. From influencing fundamental cellular processes such as signaling, recognition, and adhesion to exerting profound effects at the molecular and genetic levels, these complex carbohydrate structures emerge as linchpins in cellular functions and interactions. The structural diversity of glycoconjugates, which can be specifically classified into glycoproteins, glycolipids, and proteoglycans, underscores their importance in shaping the architecture of cells. Beyond their structural roles, these molecules also play key functions in facilitating cellular communication and modulating recognition mechanisms. Further, glycans and glycoconjugates prove invaluable as biomarkers in disease diagnostics, particularly in cancer, where aberrant glycosylation patterns offer critical diagnostic cues. Furthermore, the review explores their promising therapeutic applications, ranging from the development of glycan-based nanomaterials for precise drug delivery to innovative interventions in cancer treatment. This review endeavors to comprehensively explore the intricate functions of glycans and glycoconjugates, with the primary goal of offering valuable insights into their extensive implications in both health and disease. Encompassing a broad spectrum of biological processes, the focus of the review aims to provide a comprehensive understanding of the significant roles played by glycans and glycoconjugates.
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Affiliation(s)
- Kanika Arora
- Infectious Disease Biology Laboratory, Institute of Nano Science & Technology (INST), Sector 81, Mohali, Punjab 140306, India
| | - P M Sherilraj
- Infectious Disease Biology Laboratory, Institute of Nano Science & Technology (INST), Sector 81, Mohali, Punjab 140306, India
| | - K A Abutwaibe
- Infectious Disease Biology Laboratory, Institute of Nano Science & Technology (INST), Sector 81, Mohali, Punjab 140306, India
| | - Bharti Dhruw
- Infectious Disease Biology Laboratory, Institute of Nano Science & Technology (INST), Sector 81, Mohali, Punjab 140306, India
| | - Shyam Lal Mudavath
- Infectious Disease Biology Laboratory, Institute of Nano Science & Technology (INST), Sector 81, Mohali, Punjab 140306, India; Department of Animal Biology, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Gachibowli Hyderabad 500046, Telangana, India.
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28
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Zhang BX, Liu FF, Liu F, Qi WX, Si YQ, Ren HY, Rao XJ. SfMBP: A novel microbial binding protein and pattern recognition receptor in the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2024; 154:105142. [PMID: 38309673 DOI: 10.1016/j.dci.2024.105142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/26/2024] [Accepted: 02/01/2024] [Indexed: 02/05/2024]
Abstract
The fall armyworm, Spodoptera frugiperda, poses a significant threat as a highly destructive agricultural pest in many countries. Understanding the complex interplay between the insect immune system and entomopathogens is critical for optimizing biopesticide efficacy. In this study, we identified a novel microbial binding protein, SfMBP, in S. frugiperda. However, the specific role of SfMBP in the immune response of S. frugiperda remains elusive. Encoded by the LOC118269163 gene, SfMBP shows significant induction in S. frugiperda larvae infected with the entomopathogen Beauveria bassiana. Consisting of 115 amino acids with a signal peptide, an N-terminal flexible region and a C-terminal β-sheet, SfMBP lacks any known functional domains. It is expressed predominantly during early larval stages and in the larval epidermis. Notably, SfMBP is significantly induced in larvae infected with bacteria and fungi and in SF9 cells stimulated by peptidoglycan. While recombinant SfMBP (rSfMBP) does not inhibit bacterial growth, it demonstrates binding capabilities to bacteria, fungal spores, peptidoglycan, lipopolysaccharides, and polysaccharides. This binding is inhibited by monosaccharides and EDTA. Molecular docking reveals potential Zn2+-interacting residues and three cavities. Furthermore, rSfMBP induces bacterial agglutination in the presence of Zn2+. It also binds to insect hemocytes and SF9 cells, enhancing phagocytosis and agglutination responses. Injection of rSfMBP increased the survival of S. frugiperda larvae infected with B. bassiana, whereas blocking SfMBP with the antibody decreased survival. These results suggest that SfMBP acts as a pattern recognition receptor that enhances pathogen recognition and cellular immune responses. Consequently, this study provides valuable insights for the development of pest control measures.
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Affiliation(s)
- Bang-Xian Zhang
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, China; School of Biological Science and Food Engineering, Chuzhou, 239000, China
| | - Fang-Fang Liu
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, China
| | - Feng Liu
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, China
| | - Wen-Xuan Qi
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, China
| | - Yan-Qin Si
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, China
| | - Hai-Yan Ren
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, China
| | - Xiang-Jun Rao
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, 230036, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, China.
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29
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Romero J, Blas-Chumacero S, Urzúa V, Villasante A, Opazo R, Gajardo F, Miranda CD, Rojas R. Lysin and Lytic Phages Reduce Vibrio Counts in Live Feed and Fish Larvae. Microorganisms 2024; 12:904. [PMID: 38792735 PMCID: PMC11123823 DOI: 10.3390/microorganisms12050904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 03/19/2024] [Accepted: 03/26/2024] [Indexed: 05/26/2024] Open
Abstract
Vibrio species are naturally found in estuarine and marine ecosystems, but are also recognized as significant human enteropathogens, often linked to seafood-related illnesses. In aquaculture settings, Vibrio poses a substantial risk of infectious diseases, resulting in considerable stock losses and prompting the use of antimicrobials. However, this practice contributes to the proliferation of antimicrobial-resistant (AMR) bacteria and resistance genes. Our investigation aimed to explore the potential of biological agents such as bacteriophage CH20 and endolysin LysVPp1 in reducing Vibrio bacterial loads in both rotifer and fish larvae. LysVPp1's lytic activity was assessed by measuring absorbance reduction against various pathogenic Vibrio strains. Phage CH20 exhibited a limited host range, affecting only Vibrio alginolyticus GV09, a highly pathogenic strain. Both CH20 and LysVPp1 were evaluated for their effectiveness in reducing Vibrio load in rotifers or fish larvae through short-setting bioassays. Our results demonstrated the significant lytic effect of endolysin LysVPp1 on strains of Vibrio alginolyticus, Vibrio parahaemolyticus, and Vibrio splendidus. Furthermore, we have showcased the feasibility of reducing the load of pathogenic Vibrio in live feed and fish larvae by using a non-antibiotic-based approach, such as lytic phage and endolysin LysVPp1, thus contributing to the progress of a sustainable aquaculture from a One Health perspective.
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Affiliation(s)
- Jaime Romero
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Sergueia Blas-Chumacero
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Victoria Urzúa
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Alejandro Villasante
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Rafael Opazo
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Felipe Gajardo
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Claudio D. Miranda
- Laboratorio de Patobiología Acuática, Departamento de Acuicultura, Universidad Católica del Norte, Larrondo 1281, Coquimbo 1780000, Chile; (C.D.M.); (R.R.)
| | - Rodrigo Rojas
- Laboratorio de Patobiología Acuática, Departamento de Acuicultura, Universidad Católica del Norte, Larrondo 1281, Coquimbo 1780000, Chile; (C.D.M.); (R.R.)
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30
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Zheng Y, Zhu X, Jiang M, Cao F, You Q, Chen X. Development and Applications of D-Amino Acid Derivatives-based Metabolic Labeling of Bacterial Peptidoglycan. Angew Chem Int Ed Engl 2024; 63:e202319400. [PMID: 38284300 DOI: 10.1002/anie.202319400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/28/2024] [Accepted: 01/29/2024] [Indexed: 01/30/2024]
Abstract
Peptidoglycan, an essential component within the cell walls of virtually all bacteria, is composed of glycan strands linked by stem peptides that contain D-amino acids. The peptidoglycan biosynthesis machinery exhibits high tolerance to various D-amino acid derivatives. D-amino acid derivatives with different functionalities can thus be specifically incorporated into and label the peptidoglycan of bacteria, but not the host mammalian cells. This metabolic labeling strategy is highly selective, highly biocompatible, and broadly applicable, which has been utilized in various fields. This review introduces the metabolic labeling strategies of peptidoglycan by using D-amino acid derivatives, including one-step and two-step strategies. In addition, we emphasize the various applications of D-amino acid derivative-based metabolic labeling, including bacterial peptidoglycan visualization (existence, biosynthesis, and dynamics, etc.), bacterial visualization (including bacterial imaging and visualization of growth and division, metabolic activity, antibiotic susceptibility, etc.), pathogenic bacteria-targeted diagnostics and treatment (positron emission tomography (PET) imaging, photodynamic therapy, photothermal therapy, gas therapy, immunotherapy, etc.), and live bacteria-based therapy. Finally, a summary of this metabolic labeling and an outlook is provided.
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Affiliation(s)
- Yongfang Zheng
- Fujian-Taiwan Science and Technology Cooperation Base of Biomedical Materials and Tissue Engineering, Engineering Research Center of Industrial Biocatalysis, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Provincial Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, 32 Shangsan Road, Fuzhou, 350007, P.R. China
| | - Xinyu Zhu
- Fujian-Taiwan Science and Technology Cooperation Base of Biomedical Materials and Tissue Engineering, Engineering Research Center of Industrial Biocatalysis, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Provincial Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, 32 Shangsan Road, Fuzhou, 350007, P.R. China
| | - Mingyi Jiang
- Fujian-Taiwan Science and Technology Cooperation Base of Biomedical Materials and Tissue Engineering, Engineering Research Center of Industrial Biocatalysis, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Provincial Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, 32 Shangsan Road, Fuzhou, 350007, P.R. China
| | - Fangfang Cao
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117599, Singapore
| | - Qing You
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117599, Singapore
| | - Xiaoyuan Chen
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117599, Singapore
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Ocius KL, Kolli SH, Ahmad SS, Dressler JM, Chordia MD, Jutras BL, Rutkowski MR, Pires MM. Noninvasive Analysis of Peptidoglycan from Living Animals. Bioconjug Chem 2024; 35:489-498. [PMID: 38591251 PMCID: PMC11036361 DOI: 10.1021/acs.bioconjchem.4c00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/10/2024]
Abstract
The role of the intestinal microbiota in host health is increasingly revealed in its contributions to disease states. The host-microbiome interaction is multifactorial and dynamic. One of the factors that has recently been strongly associated with host physiological responses is peptidoglycan from bacterial cell walls. Peptidoglycan from gut commensal bacteria activates peptidoglycan sensors in human cells, including the nucleotide-binding oligomerization domain-containing protein 2. When present in the gastrointestinal tract, both the polymeric form (sacculi) and depolymerized fragments can modulate host physiology, including checkpoint anticancer therapy efficacy, body temperature and appetite, and postnatal growth. To utilize this growing area of biology toward therapeutic prescriptions, it will be critical to directly analyze a key feature of the host-microbiome interaction from living hosts in a reproducible and noninvasive way. Here we show that metabolically labeled peptidoglycan/sacculi can be readily isolated from fecal samples collected from both mice and humans. Analysis of fecal samples provided a noninvasive route to probe the gut commensal community including the metabolic synchronicity with the host circadian clock. Together, these results pave the way for noninvasive diagnostic tools to interrogate the causal nature of peptidoglycan in host health and disease.
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Affiliation(s)
- Karl L. Ocius
- Department
of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Sree H. Kolli
- Department
of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Saadman S. Ahmad
- Department
of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
- Fralin
Life Sciences Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Jules M. Dressler
- Department
of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
- Fralin
Life Sciences Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Mahendra D. Chordia
- Department
of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Brandon L. Jutras
- Department
of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
- Fralin
Life Sciences Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
- Center
for Emerging, Zoonotic and Arthropod-borne Pathogens, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Melanie R. Rutkowski
- Department
of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Marcos M. Pires
- Department
of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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32
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Zhang K, Paul K, Jacobs JP, Cockburn MG, Bronstein JM, Del Rosario I, Ritz B. Ambient long-term exposure to organophosphorus pesticides and the human gut microbiome: an observational study. Environ Health 2024; 23:41. [PMID: 38627687 PMCID: PMC11020204 DOI: 10.1186/s12940-024-01078-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 04/02/2024] [Indexed: 04/19/2024]
Abstract
BACKGROUND Organophosphorus pesticides (OP) have been associated with various human health conditions. Animal experiments and in-vitro models suggested that OP may also affect the gut microbiota. We examined associations between ambient chronic exposure to OP and gut microbial changes in humans. METHODS We recruited 190 participants from a community-based epidemiologic study of Parkinson's disease living in a region known for heavy agricultural pesticide use in California. Of these, 61% of participants had Parkinson's disease and their mean age was 72 years. Microbiome and predicted metagenome data were generated by 16S rRNA gene sequencing of fecal samples. Ambient long-term OP exposures were assessed using pesticide application records combined with residential addresses in a geographic information system. We examined gut microbiome differences due to OP exposures, specifically differences in microbial diversity based on the Shannon index and Bray-Curtis dissimilarities, and differential taxa abundance and predicted Metacyc pathway expression relying on regression models and adjusting for potential confounders. RESULTS OP exposure was not associated with alpha or beta diversity of the gut microbiome. However, the predicted metagenome was sparser and less evenly expressed among those highly exposed to OP (p = 0.04). Additionally, we found that the abundance of two bacterial families, 22 genera, and the predicted expression of 34 Metacyc pathways were associated with long-term OP exposure. These pathways included perturbed processes related to cellular respiration, increased biosynthesis and degradation of compounds related to bacterial wall structure, increased biosynthesis of RNA/DNA precursors, and decreased synthesis of Vitamin B1 and B6. CONCLUSION In support of previous animal studies and in-vitro findings, our results suggest that ambient chronic OP pesticide exposure alters gut microbiome composition and its predicted metabolism in humans.
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Affiliation(s)
- Keren Zhang
- Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, CA, USA
| | - Kimberly Paul
- Department of Neurology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Jonathan P Jacobs
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Division of Gastroenterology, Hepatology and Parenteral Nutrition, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Myles G Cockburn
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jeff M Bronstein
- Department of Neurology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Irish Del Rosario
- Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, CA, USA
| | - Beate Ritz
- Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, CA, USA.
- Department of Environmental Health Sciences, UCLA Fielding School of Public Health, Los Angeles, CA, USA.
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33
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Han JW, Lee N, Kim HJ, Moon SJ, Lee SC, Kim HJ. Weissella sp. SNUL2 as potential probiotics with broad-spectrum antimicrobial activities. Heliyon 2024; 10:e28481. [PMID: 38576583 PMCID: PMC10990963 DOI: 10.1016/j.heliyon.2024.e28481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 03/19/2024] [Accepted: 03/20/2024] [Indexed: 04/06/2024] Open
Abstract
Probiotics have been applied to a wide range of bacteria, causing gastrointestinal and vaginal infections. However, probiotics generally possess limited antimicrobial spectra and are primarily utilized as dietary supplements. Recognizing the need for more versatile probiotics, this study focuses on isolating and characterizing strains suitable for antibiotic replacement. Among these strains, Weissella sp. SNUL2, derived from a traditional fermented food in Korea (i.e., Sikhae), emerged as a promising candidate. The correlation between optical density at 600 nm and colony-forming units was verified and applied in subsequent experiments. To assess the therapeutic potential of probiotics, antibacterial tests were conducted using a microplate reader to evaluate the inhibition of 60 bacterial strains (including common foodborne pathogens) induced by Weissella sp. SNUL2 cell-free supernatant (CFS). The results confirmed its broad-spectrum antibacterial properties compared to previously known probiotics. Furthermore, enzymatic treatment with proteinases (trypsin and pepsin) and a time-kill assay were conducted to elucidate the nature of the antibacterial substance in Weissella sp. SNUL2 CFS. Through sequential chromatography involving gel filtration and ion-exchange chromatography, specific fractions with enhanced antibacterial properties were identified. LC-MS/MS analysis of the secretome fraction revealed the presence of various proteins from the C39 family, peptidoglycan endopeptidases, and N-acetylmuramoyl-l-alanine amidase domain-containing protein precursors. Hence, the combined action of these proteins may contribute to Weissella sp. SNUL2's broad antimicrobial activity.
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Affiliation(s)
- Jae Won Han
- Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Nari Lee
- Food Safety and Distribution Research Group, Research Division of Strategic Food Technology, Korea Food Research Institute, Wanju-gun 55365, Republic of Korea
| | - Hea Joon Kim
- Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Sung Jin Moon
- Department of Internal Medicine, International St. Mary's Hospital, Catholic Kwandong University, Incheon 22711, Republic of Korea
| | - Soo Chan Lee
- South Texas Center of Emerging Infectious Diseases (STCEID), Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Hyo Jin Kim
- Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
- Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
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34
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Sawabe T, Ojima Y, Nakagawa M, Sawada T, Tahara YO, Miyata M, Azuma M. Construction and characterization of a hypervesiculation strain of Escherichia coli Nissle 1917. PLoS One 2024; 19:e0301613. [PMID: 38564580 PMCID: PMC10986995 DOI: 10.1371/journal.pone.0301613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 03/19/2024] [Indexed: 04/04/2024] Open
Abstract
Outer membrane vesicles (OMVs) are produced by Gram-negative bacteria and deliver microbial molecules to distant target cells in a host. OMVs secreted by probiotic probiotic strain Escherichia coli Nissle 1917 (EcN) have been reported to induce an immune response. In this study, we aimed to increase the OMV production of EcN. The double gene knockout of mlaE and nlpI was conducted in EcN because the ΔmlaEΔnlpI of experimental strain E. coli K12 showed the highest OMV production in our previous report. The ΔmlaEΔnlpI of EcN showed approximately 8 times higher OMV production compared with the parental (wild-type) strain. Quick-freeze, deep-etch replica electron microscopy revealed that plasmolysis occurred in the elongated ΔmlaEΔnlpI cells and the peptidoglycan (PG) had numerous holes. While these phenomena are similar to the findings for the ΔmlaEΔnlpI of K12, there were more PG holes in the ΔmlaEΔnlpI of EcN than the K12 strain, which were observed not only at the tip of the long axis but also in the whole PG structure. Further analysis clarified that the viability of ΔmlaEΔnlpI of EcN decreased compared with that of the wild-type. Although the amount of PG in ΔmlaEΔnlpI cells was about half of that in wild-type, the components of amino acids in PG did not change in ΔmlaEΔnlpI. Although the viability decreased compared to the wild-type, the ΔmlaEΔnlpI grew in normal culture conditions. The hypervesiculation strain constructed here is expected to be used as an enhanced probiotic strain.
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Affiliation(s)
- Tomomi Sawabe
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Yoshihiro Ojima
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Mao Nakagawa
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Toru Sawada
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Yuhei O. Tahara
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
| | - Makoto Miyata
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
| | - Masayuki Azuma
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
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35
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Peñalver M, Paradela A, Palacios-Cuéllar C, Pucciarelli MG, García-Del Portillo F. Experimental evidence of d-glutamate racemase activity in the uncultivated bacterium Candidatus Saccharimonas aalborgensis. Environ Microbiol 2024; 26:e16621. [PMID: 38558504 DOI: 10.1111/1462-2920.16621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 03/16/2024] [Indexed: 04/04/2024]
Abstract
The Candidate Phyla Radiation (CPR) encompasses widespread uncultivated bacteria with reduced genomes and limited metabolic capacities. Most CPR bacteria lack the minimal set of enzymes required for peptidoglycan (PG) synthesis, leaving it unclear how these bacteria produce this essential envelope component. In this study, we analysed the distribution of d-amino acid racemases that produce the universal PG components d-glutamate (d-Glu) or d-alanine (d-Ala). We also examined moonlighting enzymes that synthesize d-Glu or d-Ala. Unlike other phyla in the domain Bacteria, CPR bacteria do not exhibit these moonlighting activities and have, at most, one gene encoding either a Glu or Ala racemase. One of these 'orphan' racemases is a predicted Glu racemase (MurICPR) from the CPR bacterium Candidatus Saccharimonas aalborgenesis. The expression of MurICPR restores the growth of a Salmonella d-Glu auxotroph lacking its endogenous racemase and results in the substitution of l-Ala by serine as the first residue in a fraction of the PG stem peptides. In vitro, MurICPR exclusively racemizes Glu as a substrate. Therefore, Ca. Saccharimonas aalborgensis may couple Glu racemization to serine and d-Glu incorporation into the stem peptide. Our findings provide the first insights into the synthesis of PG by an uncultivated environmental bacterium and illustrate how to experimentally test enzymatic activities from CPR bacteria related to PG metabolism.
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Affiliation(s)
- Marcos Peñalver
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Department of Molecular Biology, Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Centro de Biologia Molecular Severo Ochoa (CBM), CSIC-UAM, Madrid, Spain
| | - Alberto Paradela
- Proteomics Facility, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
| | - César Palacios-Cuéllar
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
| | - M Graciela Pucciarelli
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Department of Molecular Biology, Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Centro de Biologia Molecular Severo Ochoa (CBM), CSIC-UAM, Madrid, Spain
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36
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Hsu HC, Wang M, Kovach A, Darwin AJ, Li H. P. aeruginosa CtpA protease adopts a novel activation mechanism to initiate the proteolytic process. EMBO J 2024; 43:1634-1652. [PMID: 38467832 PMCID: PMC11021448 DOI: 10.1038/s44318-024-00069-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 02/19/2024] [Accepted: 02/26/2024] [Indexed: 03/13/2024] Open
Abstract
During bacterial cell growth, hydrolases cleave peptide cross-links between strands of the peptidoglycan sacculus to allow new strand insertion. The Pseudomonas aeruginosa carboxyl-terminal processing protease (CTP) CtpA regulates some of these hydrolases by degrading them. CtpA assembles as an inactive hexamer composed of a trimer-of-dimers, but its lipoprotein binding partner LbcA activates CtpA by an unknown mechanism. Here, we report the cryo-EM structures of the CtpA-LbcA complex. LbcA has an N-terminal adaptor domain that binds to CtpA, and a C-terminal superhelical tetratricopeptide repeat domain. One LbcA molecule attaches to each of the three vertices of a CtpA hexamer. LbcA triggers relocation of the CtpA PDZ domain, remodeling of the substrate binding pocket, and realignment of the catalytic residues. Surprisingly, only one CtpA molecule in a CtpA dimer is activated upon LbcA binding. Also, a long loop from one CtpA dimer inserts into a neighboring dimer to facilitate the proteolytic activity. This work has revealed an activation mechanism for a bacterial CTP that is strikingly different from other CTPs that have been characterized structurally.
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Affiliation(s)
- Hao-Chi Hsu
- Department of Structural Biology, Van Andel Institute, Grand Rapids, MI, USA
| | - Michelle Wang
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Amanda Kovach
- Department of Structural Biology, Van Andel Institute, Grand Rapids, MI, USA
| | - Andrew J Darwin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA.
| | - Huilin Li
- Department of Structural Biology, Van Andel Institute, Grand Rapids, MI, USA.
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37
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Pena MM, Martins TZ, Teper D, Zamuner C, Alves HA, Ferreira H, Wang N, Ferro MIT, Ferro JA. EnvC Homolog Encoded by Xanthomonas citri subsp. citri Is Necessary for Cell Division and Virulence. Microorganisms 2024; 12:691. [PMID: 38674634 PMCID: PMC11051873 DOI: 10.3390/microorganisms12040691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 03/16/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024] Open
Abstract
Peptidoglycan hydrolases are enzymes responsible for breaking the peptidoglycan present in the bacterial cell wall, facilitating cell growth, cell division and peptidoglycan turnover. Xanthomonas citri subsp. citri (X. citri), the causal agent of citrus canker, encodes an Escherichia coli M23 peptidase EnvC homolog. EnvC is a LytM factor essential for cleaving the septal peptidoglycan, thereby facilitating the separation of daughter cells. In this study, the investigation focused on EnvC contribution to the virulence and cell separation of X. citri. It was observed that disruption of the X. citri envC gene (ΔenvC) led to a reduction in virulence. Upon inoculation into leaves of Rangpur lime (Citrus limonia Osbeck), the X. citri ΔenvC exhibited a delayed onset of citrus canker symptoms compared with the wild-type X. citri. Mutant complementation restored the wild-type phenotype. Sub-cellular localization confirmed that X. citri EnvC is a periplasmic protein. Moreover, the X. citri ΔenvC mutant exhibited elongated cells, indicating a defect in cell division. These findings support the role of EnvC in the regulation of cell wall organization, cell division, and they clarify the role of this peptidase in X. citri virulence.
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Affiliation(s)
- Michelle M. Pena
- Agricultural and Livestock Microbiology Graduation Program, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal 14884-900, SP, Brazil; (M.M.P.); (T.Z.M.)
| | - Thaisa Z. Martins
- Agricultural and Livestock Microbiology Graduation Program, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal 14884-900, SP, Brazil; (M.M.P.); (T.Z.M.)
| | - Doron Teper
- Department of Plant Pathology and Weed Research, Institute of Plant Protection Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion 7505101, Israel;
| | - Caio Zamuner
- Biochemistry Building, Institute of Biosciences, São Paulo State University (UNESP), Rio Claro 13506-900, SP, Brazil; (C.Z.); (H.F.)
| | - Helen A. Alves
- Department of Agricultural, Livestock and Environmental Biotechnology, School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal 14884-900, SP, Brazil; (H.A.A.); (M.I.T.F.)
| | - Henrique Ferreira
- Biochemistry Building, Institute of Biosciences, São Paulo State University (UNESP), Rio Claro 13506-900, SP, Brazil; (C.Z.); (H.F.)
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, FL 33850, USA;
| | - Maria Inês T. Ferro
- Department of Agricultural, Livestock and Environmental Biotechnology, School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal 14884-900, SP, Brazil; (H.A.A.); (M.I.T.F.)
| | - Jesus A. Ferro
- Department of Agricultural, Livestock and Environmental Biotechnology, School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal 14884-900, SP, Brazil; (H.A.A.); (M.I.T.F.)
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38
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Yang Y, Yao Z, Zhang J, Shao W, Li B, Wu H, Tang W, Zhang J. Inhibiting Peptidoglycan Hydrolase Alleviates MRSA Pneumonia Through Autolysin-Mediated MDP-NOD2 Pathway. Infect Drug Resist 2024; 17:1231-1242. [PMID: 38560705 PMCID: PMC10981453 DOI: 10.2147/idr.s455339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 03/15/2024] [Indexed: 04/04/2024] Open
Abstract
Background Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of staph infection that is difficult to treat because of resistance to some antibiotics. A recent study indicated that diarylurea ZJ-2 is a novel antibacterial agent against multi-drug resistant Enterococcus faecium. In this work, we refined the bactericidal mechanism of ZJ-2 as a peptidoglycan (PG) hydrolase by affecting AtlA-mediated PG homeostasis. Methods A wild-type strain (WT) and a mutant strain (ΔatlA) were used to investigate the effects of ZJ-2 on the cell wall, PG, and autolysin regulatory system by antimicrobial susceptibility testing, hemolytic toxin assay, microanalysis, autolysis assay, qRT-PCR, ELISA and mouse model of pneumonia. Results The results revealed that ZJ-2 down-regulated the expression of genes related to peptidoglycan hydrolase (PGH) (sprX, walR, atlA, and lytM), and reduced the levels of PG, muramyl dipeptide (MDP), cytokines, and hemolytic toxin, while ΔatlA interfered with the genes regulation and PG homeostasis. In the mouse MRSA pneumonia model, the same trend was observed in the nucleotide oligomerization domain protein 2 (NOD2) and relative proinflammatory factors. Conclusion ZJ-2 may act as a novel inhibitor of PG hydrolyse, disrupting autolysin-mediated PG homeostasis, and reducing inflammation by down-regulating the MDP-NOD2 pathway.
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Affiliation(s)
- Yang Yang
- School of Medicine, Anhui University of Science and Technology, Huainan, People’s Republic of China
- Anhui Province Key Laboratory of Occupational Health, Anhui No.2 Provincial People’s Hospital, Hefei, People’s Republic of China
| | - Zongze Yao
- School of Medicine, Anhui University of Science and Technology, Huainan, People’s Republic of China
| | - Jiazhen Zhang
- School of Medicine, Anhui University of Science and Technology, Huainan, People’s Republic of China
| | - Wei Shao
- School of Pharmacy, Anhui Medical University, Hefei, People’s Republic of China
| | - Bo Li
- Anhui Province Key Laboratory of Occupational Health, Anhui No.2 Provincial People’s Hospital, Hefei, People’s Republic of China
| | - Huihui Wu
- Anhui Province Key Laboratory of Occupational Health, Anhui No.2 Provincial People’s Hospital, Hefei, People’s Republic of China
| | - Wenjian Tang
- School of Pharmacy, Anhui Medical University, Hefei, People’s Republic of China
| | - Jing Zhang
- Anhui Province Key Laboratory of Occupational Health, Anhui No.2 Provincial People’s Hospital, Hefei, People’s Republic of China
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39
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Aslam M, Rahman J, Iqbal A, Mujtaba S, Ashok AK, Kaouche FC, Hayat MM, Nisa MU, Ashraf M. Antiurease Activity of Antibiotics: In Vitro, In Silico, Structure Activity Relationship, and MD Simulations of Cephalosporins and Fluoroquinolones. ACS OMEGA 2024; 9:14005-14016. [PMID: 38559955 PMCID: PMC10975586 DOI: 10.1021/acsomega.3c09355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/22/2024] [Accepted: 03/01/2024] [Indexed: 04/04/2024]
Abstract
Helicobacter pylori infection is widespread in 50% of the world's population and is associated with gastric ulcers and related disorders that ultimately culminate in gastric cancer. Levofloxacin-based, or clarithromycin-based, triple therapy is frequently used to inhibit the bacterial urease enzyme for the eradication of H. pylori. A comprehensive investigation based on the urease inhibitory profiles of antibiotics and their computational implications is lacking in the scientific literature. The present study was aimed specifically to determine the antiurease activities within the realms of cephalosporins and fluoroquinolones by in vitro methods supported with in silico investigations. The results demonstrate the jack bean urease inhibitory activity of cephalosporins, wherein cefadroxil, cefpodoxime, cefotaxime, and cefaclor displayed inhibitions (IC50 21.35 ± 0.64 to 62.86 ± 0.78 μM) compared with the standard thiourea (IC50 21.25 ± 0.15 μM). Among fluoroquinolones, levofloxacin, ofloxacin, and gemifloxacin (IC50 7.24 ± 0.29 to 16.53 ± 0.85 μM) unveiled remarkable inhibitory profiles. Levofloxacin and ofloxacin exhibited competitive inhibition against the said enzyme. Ciprofloxacin and moxifloxacin displayed weak urease inhibitions. During molecular docking studies, Asp362, Gly279, Arg338, Asn168, Asp223, Gln364, and Met366 were involved in hydrogen bonding in fluoroquinolones, and hydrogen bonding was established with Arg338, His248, Asn168 residues, and metal Ni601 and Ni602 of the enzyme. MD simulations and MMPBSA results demonstrated the existence of significant protein-ligand binding. Overall, these results warrant further investigations into the significance of these active molecules in relation to their inhibitory potential against the targeted urease enzyme.
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Affiliation(s)
- Misbah Aslam
- Institute
of Chemistry, B.J. Campus, The Islamia University
of Bahawalpur, Bahawalpur 36000, Pakistan
| | - Jameel Rahman
- Institute
of Chemistry, B.J. Campus, The Islamia University
of Bahawalpur, Bahawalpur 36000, Pakistan
| | - Ambar Iqbal
- Institute
of Chemistry, B.J. Campus, The Islamia University
of Bahawalpur, Bahawalpur 36000, Pakistan
- Department
of Biochemistry and Molecular Biology, Institute of Biochemistry,
Biotechnology, Bioinformatics (IBBB), B.J. Campus, The Islamia University of Bahawalpur, Bahawalpur 36000, Pakistan
| | - Sara Mujtaba
- Institute
of Chemistry, B.J. Campus, The Islamia University
of Bahawalpur, Bahawalpur 36000, Pakistan
| | - Avinash Karkada Ashok
- Department
of Biotechnology, Siddaganga Institute of
Technology, Tumakuru 572103, Karnataka, India
| | - Farah Chafika Kaouche
- Department
of Chemistry, Faculty of Sciences of Mater, Ibn Khaldoun University, BP 78 zaaoura, 14000 Tiaret, Algeria
| | - Muhammad Munawar Hayat
- P
& SH Department, Punjab Drug Testing
Laboratory, 1-Bird Wood
Road, Lahore 631000, Pakistan
| | - Mouqadus-Un Nisa
- Multan Drug
Testing Laboratory, near Multan Institute
of Kidney Disease, Muzaffargarh
Road, Multan 261000, Pakistan
| | - Muhammad Ashraf
- Institute
of Chemistry, B.J. Campus, The Islamia University
of Bahawalpur, Bahawalpur 36000, Pakistan
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40
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Modi M, Thambiraja M, Cherukat A, Yennamalli RM, Priyadarshini R. Structure predictions and functional insights into Amidase_3 domain containing N-acetylmuramyl-L-alanine amidases from Deinococcus indicus DR1. BMC Microbiol 2024; 24:101. [PMID: 38532329 DOI: 10.1186/s12866-024-03225-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 02/15/2024] [Indexed: 03/28/2024] Open
Abstract
BACKGROUND N-acetylmuramyl-L-alanine amidases are cell wall modifying enzymes that cleave the amide bond between the sugar residues and stem peptide in peptidoglycan. Amidases play a vital role in septal cell wall cleavage and help separate daughter cells during cell division. Most amidases are zinc metalloenzymes, and E. coli cells lacking amidases grow as chains with daughter cells attached to each other. In this study, we have characterized two amidase enzymes from Deinococcus indicus DR1. D. indicus DR1 is known for its high arsenic tolerance and unique cell envelope. However, details of their cell wall biogenesis remain largely unexplored. RESULTS We have characterized two amidases Ami1Di and Ami2Di from D. indicus DR1. Both Ami1Di and Ami2Di suppress cell separation defects in E. coli amidase mutants, suggesting that these enzymes are able to cleave septal cell wall. Ami1Di and Ami2Di proteins possess the Amidase_3 catalytic domain with conserved -GHGG- motif and Zn2+ binding sites. Zn2+- binding in Ami1Di is crucial for amidase activity. AlphaFold2 structures of both Ami1Di and Ami2Di were predicted, and Ami1Di was a closer homolog to AmiA of E. coli. CONCLUSION Our results indicate that Ami1Di and Ami2Di enzymes can cleave peptidoglycan, and structural prediction studies revealed insights into the activity and regulation of these enzymes in D. indicus DR1.
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Affiliation(s)
- Malvika Modi
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, 201314, India
| | - Menaka Thambiraja
- Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, Tamil Nadu, 613401, India
| | - Archana Cherukat
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, 201314, India
- Department of Biology, Graduate School of Arts and Sciences, Wake Forest University, 1834 Wake Forest Rd, Winston-Salem, USA
| | - Ragothaman M Yennamalli
- Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, Tamil Nadu, 613401, India
| | - Richa Priyadarshini
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, 201314, India.
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41
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Coppinger MN, Laramore K, Popham DL, Stabb EV. A prototrophic suppressor of a Vibrio fischeri D-glutamate auxotroph reveals a member of the periplasmic broad-spectrum racemase family (BsrF). J Bacteriol 2024; 206:e0033323. [PMID: 38411059 PMCID: PMC10955857 DOI: 10.1128/jb.00333-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/04/2024] [Indexed: 02/28/2024] Open
Abstract
Although bacterial peptidoglycan (PG) is highly conserved, some natural variations in PG biosynthesis and structure have evolved. Understanding the mechanisms and limits of such variation will inform our understanding of antibiotic resistance, innate immunity, and the evolution of bacteria. We have explored the constraints on PG evolution by blocking essential steps in PG biosynthesis in Vibrio fischeri and then selecting mutants with restored prototrophy. Here, we attempted to select prototrophic suppressors of a D-glutamate auxotrophic murI racD mutant. No suppressors were isolated on unsupplemented lysogeny broth salts (LBS), despite plating >1011 cells, nor were any suppressors generated through mutagenesis with ethyl methanesulfonate. A single suppressor was isolated on LBS supplemented with iso-D-gln, although the iso-D-gln subsequently appeared irrelevant. This suppressor has a genomic amplification formed by the creation of a novel junction that fuses proB to a gene encoding a putative broad-spectrum racemase of V. fischeri, bsrF. An engineered bsrF allele lacking the putative secretion signal (ΔSS-bsrF) also suppressed D-glu auxotrophy, resulting in PG that was indistinguishable from the wild type. The ΔSS-bsrF allele similarly suppressed the D-alanine auxotrophy of an alr mutant and restored prototrophy to a murI alr double mutant auxotrophic for both D-ala and D-glu. The ΔSS-bsrF allele increased resistance to D-cycloserine but had no effect on sensitivity to PG-targeting antibiotics penicillin, ampicillin, or vancomycin. Our work helps define constraints on PG evolution and reveals a periplasmic broad-spectrum racemase in V. fischeri that can be co-opted for PG biosynthesis, with concomitant D-cycloserine resistance. IMPORTANCE D-Amino acids are used and produced by organisms across all domains of life, but often, their origins and roles are not well understood. In bacteria, D-ala and D-glu are structural components of the canonical peptidoglycan cell wall and are generated by dedicated racemases Alr and MurI, respectively. The more recent discovery of additional bacterial racemases is broadening our view and deepening our understanding of D-amino acid metabolism. Here, while exploring alternative PG biosynthetic pathways in Vibrio fischeri, we unexpectedly shed light on an unusual racemase, BsrF. Our results illustrate a novel mechanism for the evolution of antibiotic resistance and provide a new avenue for exploring the roles of non-canonical racemases and D-amino acids in bacteria.
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Affiliation(s)
- Macey N. Coppinger
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
- Department of Biological Sciences, University of Illinois, Chicago, Illinois, USA
| | - Kathrin Laramore
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - David L. Popham
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Eric V. Stabb
- Department of Biological Sciences, University of Illinois, Chicago, Illinois, USA
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42
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Antillon SF, Bernhardt TG, Chamakura K, Young R. Physiological characterization of single-gene lysis proteins. J Bacteriol 2024; 206:e0038423. [PMID: 38426721 PMCID: PMC10955853 DOI: 10.1128/jb.00384-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/07/2024] [Indexed: 03/02/2024] Open
Abstract
Single-strand RNA (ssRNA) and single-strand DNA phages elicit host lysis using a single gene, in each case designated as sgl. Of the 11 identified Sgls, three have been shown to be specific inhibitors of different steps in the pathway that supplies lipid II to the peptidoglycan (PG) biosynthesis machinery. These Sgls have been called "protein antibiotics" because the lytic event is a septal catastrophe indistinguishable from that caused by cell wall antibiotics. Here, we designate these as type I Sgls. In this formalism, the other eight Sgls are assigned to type II, the best-studied of which is protein L of the paradigm F-specific ssRNA phage MS2. Comparisons have suggested that type II Sgls have four sequence elements distinguished by hydrophobic and polar character. Environmental metatranscriptomics has revealed thousands of new ssRNA phage genomes, each of which presumably has an Sgl. Here, we describe methods to distinguish type I and type II Sgls. Using phase contrast microscopy, we show that both classes of Sgls cause the formation of blebs prior to lysis, but the location of the blebs differs significantly. In addition, we show that L and other type II Sgls do not inhibit the net synthesis of PG, as measured by radio-labeling of PG. Finally, we provide direct evidence that the Sgl from Pseudomonas phage PP7 is a type I Sgl, in support of a recent report based on a genetic selection. This shows that the putative four-element sequence structure suggested for L is not a reliable discriminator for the operational characterization of Sgls. IMPORTANCE The ssRNA phage world has recently undergone a metagenomic expansion upward of a thousandfold. Each genome likely carries at least one single-gene lysis (sgl) cistron encoding a protein that single-handedly induces host autolysis. Here, we initiate an approach to segregate the Sgls into operational types based on physiological analysis, as a first step toward the alluring goal of finding many new ways to induce bacterial death and the attendant expectations for new antibiotic development.
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Affiliation(s)
- S. Francesca Antillon
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
- Center for Phage Technology, Texas A&M AgriLife Research, College Station, Texas, USA
| | - Thomas G. Bernhardt
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| | - Karthik Chamakura
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
- Center for Phage Technology, Texas A&M AgriLife Research, College Station, Texas, USA
| | - Ry Young
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
- Center for Phage Technology, Texas A&M AgriLife Research, College Station, Texas, USA
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43
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Bollinger KW, Müh U, Ocius KL, Apostolos AJ, Pires MM, Helm RF, Popham DL, Weiss DS, Ellermeier CD. Identification of a new family of peptidoglycan transpeptidases reveals atypical crosslinking is essential for viability in Clostridioides difficile. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.14.584917. [PMID: 38559057 PMCID: PMC10980060 DOI: 10.1101/2024.03.14.584917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Clostridioides difficile, the leading cause of antibiotic-associated diarrhea, relies primarily on 3-3 crosslinks created by L,D-transpeptidases (LDTs) to fortify its peptidoglycan (PG) cell wall. This is unusual, as in most bacteria the vast majority of PG crosslinks are 4-3 crosslinks, which are created by penicillin-binding proteins (PBPs). Here we report the unprecedented observation that 3-3 crosslinking is essential for viability in C. difficile. We also report the discovery of a new family of LDTs that use a VanW domain to catalyze 3-3 crosslinking rather than a YkuD domain as in all previously known LDTs. Bioinformatic analyses indicate VanW domain LDTs are less common than YkuD domain LDTs and are largely restricted to Gram-positive bacteria. Our findings suggest that LDTs might be exploited as targets for antibiotics that kill C. difficile without disrupting the intestinal microbiota that is important for keeping C. difficile in check.
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Affiliation(s)
- Kevin W. Bollinger
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Ute Müh
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Karl L. Ocius
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Alexis J. Apostolos
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
- Present address: Haleon, 1211 Sherwood Ave, Richmond, VA 23220
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Richard F. Helm
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
| | - David L. Popham
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - David S. Weiss
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Graduate Program in Genetics, University of Iowa, Iowa City, IA USA
| | - Craig D. Ellermeier
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Graduate Program in Genetics, University of Iowa, Iowa City, IA USA
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Hillman A, Hyland SN, Wodzanowski KA, Moore DL, Ratna S, Jemas A, Sandles LMD, Chaya T, Ghosh A, Fox JM, Grimes CL. Minimalist Tetrazine N-Acetyl Muramic Acid Probes for Rapid and Efficient Labeling of Commensal and Pathogenic Peptidoglycans in Living Bacterial Culture and During Macrophage Invasion. J Am Chem Soc 2024; 146:6817-6829. [PMID: 38427023 PMCID: PMC10941766 DOI: 10.1021/jacs.3c13644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/13/2024] [Accepted: 02/14/2024] [Indexed: 03/02/2024]
Abstract
N-Acetyl muramic acid (NAM) probes containing alkyne or azide groups are commonly used to investigate aspects of cell wall synthesis because of their small size and ability to incorporate into bacterial peptidoglycan (PG). However, copper-catalyzed alkyne-azide cycloaddition (CuAAC) reactions are not compatible with live cells, and strain-promoted alkyne-azide cycloaddition (SPAAC) reaction rates are modest and, therefore, not as desirable for tracking the temporal alterations of bacterial cell growth, remodeling, and division. Alternatively, the tetrazine-trans-cyclooctene ligation (Tz-TCO), which is the fastest known bioorthogonal reaction and not cytotoxic, allows for rapid live-cell labeling of PG at biologically relevant time scales and concentrations. Previous work to increase reaction kinetics on the PG surface by using tetrazine probes was limited because of low incorporation of the probe. Described here are new approaches to construct a minimalist tetrazine (Tz)-NAM probe utilizing recent advancements in asymmetric tetrazine synthesis. This minimalist Tz-NAM probe was successfully incorporated into pathogenic and commensal bacterial PG where fixed and rapid live-cell, no-wash labeling was successful in both free bacterial cultures and in coculture with human macrophages. Overall, this probe allows for expeditious labeling of bacterial PG, thereby making it an exceptional tool for monitoring PG biosynthesis for the development of new antibiotic screens. The versatility and selectivity of this probe will allow for real-time interrogation of the interactions of bacterial pathogens in a human host and will serve a broader utility for studying glycans in multiple complex biological systems.
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Affiliation(s)
- Ashlyn
S. Hillman
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
| | - Stephen N. Hyland
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
| | - Kimberly A. Wodzanowski
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
| | - DeVonte L. Moore
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
| | - Sushanta Ratna
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
| | - Andrew Jemas
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
| | - Liam-Michael D. Sandles
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
| | - Timothy Chaya
- Department
of Plant and Soil Sciences, University of
Delaware, Newark, Delaware 19716, United States
| | - Arit Ghosh
- Delaware
Biotechnology Institute, UDEL Flow Cytometry Core, University of Delaware, Newark, Delaware 19716, United States
| | - Joseph M. Fox
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
- Department
of Materials Science and Engineering, University
of Delaware, Newark, Delaware 19716, United States
| | - Catherine L. Grimes
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
- Department
of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
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45
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VanOtterloo LM, Macias LA, Powers MJ, Brodbelt JS, Trent MS. Characterization of Acinetobacter baumannii core oligosaccharide synthesis reveals novel aspects of lipooligosaccharide assembly. mBio 2024; 15:e0301323. [PMID: 38349180 PMCID: PMC10936431 DOI: 10.1128/mbio.03013-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/12/2024] [Indexed: 03/14/2024] Open
Abstract
A fundamental feature of Gram-negative bacteria is their outer membrane that protects the cell against environmental stressors. This defense is predominantly due to its asymmetry, with glycerophospholipids located in the inner leaflet and lipopolysaccharide (LPS) or lipooligosaccharide (LOS) confined to the outer leaflet. LPS consists of a lipid A anchor, a core oligosaccharide, and a distal O-antigen while LOS lacks O-antigen. While LPS/LOS is typically essential for growth, this is not the case for Acinetobacter baumannii. Despite this unique property, the synthesis of the core oligosaccharide of A. baumannii LOS is not well-described. Here, we characterized the LOS chemotypes of A. baumannii strains with mutations in a predicted core oligosaccharide locus via tandem mass spectrometry. This allowed for an extensive identification of genes required for core assembly that can be exploited to generate precise structural LOS modifications in many A. baumannii strains. We further investigated two chemotypically identical yet phenotypically distinct mutants, ∆2903 and ∆lpsB, that exposed a possible link between LOS and the peptidoglycan cell wall-two cell envelope components whose coordination has not yet been described in A. baumannii. Selective reconstruction of the core oligosaccharide via expression of 2903 and LpsB revealed that these proteins rely on each other for the unusual tandem transfer of two residues, KdoIII and N-acetylglucosaminuronic acid. The data presented not only allow for better usage of A. baumannii as a tool to study outer membrane integrity but also provide further evidence for a novel mechanism of core oligosaccharide assembly. IMPORTANCE Acinetobacter baumannii is a multidrug-resistant pathogen that produces lipooligosaccharide (LOS), a glycolipid that confers protective asymmetry to the bacterial outer membrane. The core oligosaccharide is a ubiquitous component of LOS that typically follows a well-established model of synthesis. In addition to providing an extensive analysis of the genes involved in the synthesis of the core region, we demonstrate that this organism has evidently diverged from the long-held archetype of core synthesis. Moreover, our data suggest that A. baumannii LOS assembly is important for cell division and likely intersects with the synthesis of the peptidoglycan cell wall, another essential component of the Gram-negative cell envelope. This connection between LOS and cell wall synthesis provides an intriguing foundation for a unique method of outer membrane biogenesis and cell envelope coordination.
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Affiliation(s)
- Leah M. VanOtterloo
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
| | - Luis A. Macias
- Department of Chemistry, University of Texas at Austin, Austin, Texas, USA
| | - Matthew J. Powers
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
| | | | - M. Stephen Trent
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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46
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Chew NSL, Ooi CW, Yeo LY, Tan MK. Influence of MHz-order acoustic waves on bacterial suspensions. ULTRASONICS 2024; 138:107234. [PMID: 38171227 DOI: 10.1016/j.ultras.2023.107234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/22/2023] [Accepted: 12/24/2023] [Indexed: 01/05/2024]
Abstract
The development of alternative techniques to efficiently inactivate bacterial suspensions is crucial to prevent transmission of waterborne illness, particularly when commonly used techniques such as heating, filtration, chlorination, or ultraviolet treatment are not practical or feasible. We examine the effect of MHz-order acoustic wave irradiation in the form of surface acoustic waves (SAWs) on Gram-positive (Escherichia coli) and Gram-negative (Brevibacillus borstelensis and Staphylococcus aureus) bacteria suspended in water droplets. A significant increase in the relative bacterial load reduction of colony-forming units (up to 74%) can be achieved by either increasing (1) the excitation power, or, (2) the acoustic treatment duration, which we attributed to the effect of the acoustic radiation force exerted on the bacteria. Consequently, by increasing the maximum pressure amplitude via a hybrid modulation scheme involving a combination of amplitude and pulse-width modulation, we observe that the bacterial inactivation efficiency can be further increased by approximately 14%. By combining this scalable acoustic-based bacterial inactivation platform with plasma-activated water, a 100% reduction in E. coli is observed in less than 10 mins, therefore demonstrating the potential of the synergistic effects of MHz-order acoustic irradiation and plasma-activated water as an efficient strategy for water decontamination.
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Affiliation(s)
- Nicholas S L Chew
- Department of Mechanical Engineering, School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia
| | - Chien W Ooi
- Department of Chemical Engineering, School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia
| | - Leslie Y Yeo
- Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3001, Australia
| | - Ming K Tan
- Department of Mechanical Engineering, School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia.
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47
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Thweatt JL, Harman CE, Araújo MN, Marlow JJ, Oliver GC, Sabuda MC, Sevgen S, Wilpiszeki RL. Chapter 6: The Breadth and Limits of Life on Earth. ASTROBIOLOGY 2024; 24:S124-S142. [PMID: 38498824 DOI: 10.1089/ast.2021.0131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Scientific ideas about the potential existence of life elsewhere in the universe are predominantly informed by knowledge about life on Earth. Over the past ∼4 billion years, life on Earth has evolved into millions of unique species. Life now inhabits nearly every environmental niche on Earth that has been explored. Despite the wide variety of species and diverse biochemistry of modern life, many features, such as energy production mechanisms and nutrient requirements, are conserved across the Tree of Life. Such conserved features help define the operational parameters required by life and therefore help direct the exploration and evaluation of habitability in extraterrestrial environments. As new diversity in the Tree of Life continues to expand, so do the known limits of life on Earth and the range of environments considered habitable elsewhere. The metabolic processes used by organisms living on the edge of habitability provide insights into the types of environments that would be most suitable to hosting extraterrestrial life, crucial for planning and developing future astrobiology missions. This chapter will introduce readers to the breadth and limits of life on Earth and show how the study of life at the extremes can inform the broader field of astrobiology.
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Affiliation(s)
- Jennifer L Thweatt
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA. (Former)
| | - C E Harman
- Planetary Systems Branch, NASA Ames Research Center, Moffett Field, California, USA
| | - M N Araújo
- Biochemistry Department, University of São Paulo, São Carlos, Brazil
| | - Jeffrey J Marlow
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Gina C Oliver
- Department of Geology, San Bernardino Valley College, San Bernardino, California, USA
| | - Mary C Sabuda
- Department of Earth and Environmental Sciences, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA
- Biotechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, USA
| | - Serhat Sevgen
- Institute of Marine Sciences, Middle East Technical University, Erdemli, Mersin, Turkey
- Blue Marble Space Institute of Science, Seattle, Washington, USA
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48
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Oechslin F, Zhu X, Morency C, Somerville V, Shi R, Moineau S. Fermentation Practices Select for Thermostable Endolysins in Phages. Mol Biol Evol 2024; 41:msae055. [PMID: 38489607 PMCID: PMC10980517 DOI: 10.1093/molbev/msae055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/12/2024] [Accepted: 03/07/2024] [Indexed: 03/17/2024] Open
Abstract
Endolysins are produced by (bacterio)phages and play a crucial role in degrading the bacterial cell wall and the subsequent release of new phage progeny. These lytic enzymes exhibit a remarkable diversity, often occurring in a multimodular form that combines different catalytic and cell wall-binding domains, even in phages infecting the same species. Yet, our current understanding lacks insight into how environmental factors and ecological niches may have influenced the evolution of these enzymes. In this study, we focused on phages infecting Streptococcus thermophilus, as this bacterial species has a well-defined and narrow ecological niche, namely, dairy fermentation. Among the endolysins found in phages targeting this species, we observed limited diversity, with a singular structural type dominating in most of identified S. thermophilus phages. Within this prevailing endolysin type, we discovered a novel and highly conserved calcium-binding motif. This motif proved to be crucial for the stability and activity of the enzyme at elevated temperatures. Ultimately, we demonstrated its positive selection within the host's environmental conditions, particularly under the temperature profiles encountered in the production of yogurt, mozzarella, and hard cheeses that rely on S. thermophilus.
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Affiliation(s)
- Frank Oechslin
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, Université Laval, Quebec City, Canada
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, Canada
| | - Xiaojun Zhu
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, Université Laval, Quebec City, Canada
| | - Carlee Morency
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, Université Laval, Quebec City, Canada
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, Canada
| | - Vincent Somerville
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, Université Laval, Quebec City, Canada
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, Canada
- Department of Microbiology & Immunology, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
| | - Rong Shi
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, Université Laval, Quebec City, Canada
| | - Sylvain Moineau
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, Université Laval, Quebec City, Canada
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, Canada
- Félix d’Hérelle Reference Center for Bacterial Viruses, Université Laval, Québec City, Canada
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Espaillat A, Alvarez L, Torrens G, Ter Beek J, Miguel-Ruano V, Irazoki O, Gago F, Hermoso JA, Berntsson RPA, Cava F. A distinctive family of L,D-transpeptidases catalyzing L-Ala-mDAP crosslinks in Alpha- and Betaproteobacteria. Nat Commun 2024; 15:1343. [PMID: 38351082 PMCID: PMC10864386 DOI: 10.1038/s41467-024-45620-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/29/2024] [Indexed: 02/16/2024] Open
Abstract
The bacterial cell-wall peptidoglycan is made of glycan strands crosslinked by short peptide stems. Crosslinks are catalyzed by DD-transpeptidases (4,3-crosslinks) and LD-transpeptidases (3,3-crosslinks). However, recent research on non-model species has revealed novel crosslink types, suggesting the existence of uncharacterized enzymes. Here, we identify an LD-transpeptidase, LDTGo, that generates 1,3-crosslinks in the acetic-acid bacterium Gluconobacter oxydans. LDTGo-like proteins are found in Alpha- and Betaproteobacteria lacking LD3,3-transpeptidases. In contrast with the strict specificity of typical LD- and DD-transpeptidases, LDTGo can use non-terminal amino acid moieties for crosslinking. A high-resolution crystal structure of LDTGo reveals unique features when compared to LD3,3-transpeptidases, including a proline-rich region that appears to limit substrate access, and a cavity accommodating both glycan chain and peptide stem from donor muropeptides. Finally, we show that DD-crosslink turnover is involved in supplying the necessary substrate for LD1,3-transpeptidation. This phenomenon underscores the interplay between distinct crosslinking mechanisms in maintaining cell wall integrity in G. oxydans.
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Affiliation(s)
- Akbar Espaillat
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, SciLifeLab, Umeå University, Umeå, Sweden
- Chr. Hansen A/S, Microbial Physiology, R&D, 2970, Hoersholm, Denmark
| | - Laura Alvarez
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, SciLifeLab, Umeå University, Umeå, Sweden
| | - Gabriel Torrens
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, SciLifeLab, Umeå University, Umeå, Sweden
| | - Josy Ter Beek
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Vega Miguel-Ruano
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Blas Cabrera", CSIC, Madrid, Spain
| | - Oihane Irazoki
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, SciLifeLab, Umeå University, Umeå, Sweden
| | - Federico Gago
- Department of Biomedical Sciences & IQM-CSIC Associate Unit, School of Medicine and Health Sciences, University of Alcalá, E-28805, Madrid, Alcalá de Henares, Spain
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Blas Cabrera", CSIC, Madrid, Spain
| | - Ronnie P-A Berntsson
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Felipe Cava
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, SciLifeLab, Umeå University, Umeå, Sweden.
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50
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Stephani J, Gerhards L, Khairalla B, Solov’yov IA, Brand I. How do Antimicrobial Peptides Interact with the Outer Membrane of Gram-Negative Bacteria? Role of Lipopolysaccharides in Peptide Binding, Anchoring, and Penetration. ACS Infect Dis 2024; 10:763-778. [PMID: 38259029 PMCID: PMC10862549 DOI: 10.1021/acsinfecdis.3c00673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/31/2023] [Accepted: 01/02/2024] [Indexed: 01/24/2024]
Abstract
Gram-negative bacteria possess a complex structural cell envelope that constitutes a barrier for antimicrobial peptides that neutralize the microbes by disrupting their cell membranes. Computational and experimental approaches were used to study a model outer membrane interaction with an antimicrobial peptide, melittin. The investigated membrane included di[3-deoxy-d-manno-octulosonyl]-lipid A (KLA) in the outer leaflet and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) in the inner leaflet. Molecular dynamics simulations revealed that the positively charged helical C-terminus of melittin anchors rapidly into the hydrophilic headgroup region of KLA, while the flexible N-terminus makes contacts with the phosphate groups of KLA, supporting melittin penetration into the boundary between the hydrophilic and hydrophobic regions of the lipids. Electrochemical techniques confirmed the binding of melittin to the model membrane. To probe the peptide conformation and orientation during interaction with the membrane, polarization modulation infrared reflection absorption spectroscopy was used. The measurements revealed conformational changes in the peptide, accompanied by reorientation and translocation of the peptide at the membrane surface. The study suggests that melittin insertion into the outer membrane affects its permeability and capacitance but does not disturb the membrane's bilayer structure, indicating a distinct mechanism of the peptide action on the outer membrane of Gram-negative bacteria.
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Affiliation(s)
- Justus
C. Stephani
- Institute
of Physics, Carl von Ossietzky University
of Oldenburg, 26111 Oldenburg, Germany
| | - Luca Gerhards
- Institute
of Physics, Carl von Ossietzky University
of Oldenburg, 26111 Oldenburg, Germany
| | - Bishoy Khairalla
- Department
of Chemistry, Carl von Ossietzky University
of Oldenburg, 26111 Oldenburg, Germany
| | - Ilia A. Solov’yov
- Institute
of Physics, Carl von Ossietzky University
of Oldenburg, 26111 Oldenburg, Germany
- Research
Center Neurosensory Science, Carl von Ossietzky
University of Oldenburg, 26111 Oldenburg, Germany
- CeNaD—Center
for Nanoscale Dynamics, Carl von Ossietzky
University of Oldenburg, 26111 Oldenburg, Germany
| | - Izabella Brand
- Department
of Chemistry, Carl von Ossietzky University
of Oldenburg, 26111 Oldenburg, Germany
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