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Zhang H, You J, Pan X, Hu Y, Zhang Z, Zhang X, Zhang W, Rao Z. Genomic and biological insights of bacteriophages JNUWH1 and JNUWD in the arms race against bacterial resistance. Front Microbiol 2024; 15:1407039. [PMID: 38989022 PMCID: PMC11233448 DOI: 10.3389/fmicb.2024.1407039] [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: 03/27/2024] [Accepted: 06/07/2024] [Indexed: 07/12/2024] Open
Abstract
The coevolution of bacteria and bacteriophages has created a great diversity of mechanisms by which bacteria fight phage infection, and an equivalent diversity of mechanisms by which phages subvert bacterial immunity. Effective and continuous evolution by phages is necessary to deal with coevolving bacteria. In this study, to better understand the connection between phage genes and host range, we examine the isolation and genomic characterization of two bacteriophages, JNUWH1 and JNUWD, capable of infecting Escherichia coli. Sourced from factory fermentation pollutants, these phages were classified within the Siphoviridae family through TEM and comparative genomic analysis. Notably, the phages exhibited a viral burst size of 500 and 1,000 PFU/cell, with latent periods of 15 and 20 min, respectively. They displayed stability over a pH range of 5 to 10, with optimal activity at 37°C. The complete genomes of JNUWH1 and JNUWD were 44,785 bp and 43,818 bp, respectively. Phylogenetic analysis revealed their close genetic relationship to each other. Antibacterial assays demonstrated the phages' ability to inhibit E. coli growth for up to 24 h. Finally, through laboratory-driven adaptive evolution, we successfully identified strains for both JNUWH1 and JNUWD with mutations in receptors specifically targeting lipopolysaccharides (LPS) and the lptD gene. Overall, these phages hold promise as additives in fermentation products to counter E. coli, offering potential solutions in the context of evolving bacterial resistance.
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Affiliation(s)
- Hengwei Zhang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Jiajia You
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Xuewei Pan
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Yanglu Hu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Zan Zhang
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Xian Zhang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Weiguo Zhang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
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Zhang P, Zhang B, Ji Y, Jiao J, Zhang Z, Tian C. Cofitness network connectivity determines a fuzzy essential zone in open bacterial pangenome. MLIFE 2024; 3:277-290. [PMID: 38948139 PMCID: PMC11211677 DOI: 10.1002/mlf2.12132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 04/20/2024] [Accepted: 04/24/2024] [Indexed: 07/02/2024]
Abstract
Most in silico evolutionary studies commonly assumed that core genes are essential for cellular function, while accessory genes are dispensable, particularly in nutrient-rich environments. However, this assumption is seldom tested genetically within the pangenome context. In this study, we conducted a robust pangenomic Tn-seq analysis of fitness genes in a nutrient-rich medium for Sinorhizobium strains with a canonical open pangenome. To evaluate the robustness of fitness category assignment, Tn-seq data for three independent mutant libraries per strain were analyzed by three methods, which indicates that the Hidden Markov Model (HMM)-based method is most robust to variations between mutant libraries and not sensitive to data size, outperforming the Bayesian and Monte Carlo simulation-based methods. Consequently, the HMM method was used to classify the fitness category. Fitness genes, categorized as essential (ES), advantage (GA), and disadvantage (GD) genes for growth, are enriched in core genes, while nonessential genes (NE) are over-represented in accessory genes. Accessory ES/GA genes showed a lower fitness effect than core ES/GA genes. Connectivity degrees in the cofitness network decrease in the order of ES, GD, and GA/NE. In addition to accessory genes, 1599 out of 3284 core genes display differential essentiality across test strains. Within the pangenome core, both shared quasi-essential (ES and GA) and strain-dependent fitness genes are enriched in similar functional categories. Our analysis demonstrates a considerable fuzzy essential zone determined by cofitness connectivity degrees in Sinorhizobium pangenome and highlights the power of the cofitness network in understanding the genetic basis of ever-increasing prokaryotic pangenome data.
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Affiliation(s)
- Pan Zhang
- State Key Laboratory of Plant Environmental Resilience, and College of Biological SciencesChina Agricultural UniversityBeijingChina
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
- Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina
| | - Biliang Zhang
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
- State Key Laboratory of Livestock and Poultry Biotechnology Breeding, and College of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Yuan‐Yuan Ji
- State Key Laboratory of Plant Environmental Resilience, and College of Biological SciencesChina Agricultural UniversityBeijingChina
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
| | - Jian Jiao
- State Key Laboratory of Plant Environmental Resilience, and College of Biological SciencesChina Agricultural UniversityBeijingChina
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
| | - Ziding Zhang
- State Key Laboratory of Livestock and Poultry Biotechnology Breeding, and College of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Chang‐Fu Tian
- State Key Laboratory of Plant Environmental Resilience, and College of Biological SciencesChina Agricultural UniversityBeijingChina
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
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Hartojo A, Doyle MT. β-barrel membrane proteins fold via hybrid-barrel intermediate states. Curr Opin Struct Biol 2024; 87:102830. [PMID: 38728831 DOI: 10.1016/j.sbi.2024.102830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/15/2024] [Accepted: 04/22/2024] [Indexed: 05/12/2024]
Abstract
Gram-negative bacteria and eukaryotic organelles of bacterial origin contain outer membrane proteins that possess a transmembrane "β-barrel" domain. The conserved β-barrel assembly machine (BAM) and the sorting and assembly machine (SAM) are required for the folding and membrane insertion of β-barrels in Gram-negative bacteria and mitochondria, respectively. Although the mechanisms by which β-barrels are folded are incompletely understood, advances in cryo-electron microscopy (cryo-EM) have recently yielded unprecedented insights into their folding process. Here we highlight recent studies that show that both bacterial and mitochondrial β-barrels fold via the formation of remarkable "hybrid-barrel" intermediate states during their interaction with the folding machinery. We discuss how these results align with a general model of β-barrel folding.
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Affiliation(s)
- Alfred Hartojo
- Sydney Infectious Diseases Institute, The University of Sydney, Darlington, New South Wales, Australia; School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Darlington, New South Wales, Australia. https://twitter.com/AlfredHartojo29
| | - Matthew Thomas Doyle
- Sydney Infectious Diseases Institute, The University of Sydney, Darlington, New South Wales, Australia; School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Darlington, New South Wales, Australia.
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Rodas-Junco BA, Hernández-Solís SE, Serralta-Interian AA, Rueda-Gordillo F. Dental Stem Cells and Lipopolysaccharides: A Concise Review. Int J Mol Sci 2024; 25:4338. [PMID: 38673923 PMCID: PMC11049850 DOI: 10.3390/ijms25084338] [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: 03/10/2024] [Revised: 04/06/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Dental tissue stem cells (DTSCs) are well known for their multipotent capacity and regenerative potential. They also play an important role in the immune response of inflammatory processes derived from caries lesions, periodontitis, and gingivitis. These oral diseases are triggered by toxins known as lipopolysaccharides (LPS) produced by gram-negative bacteria. LPS present molecular patterns associated with pathogens and are recognized by Toll-like receptors (TLRs) in dental stem cells. In this review, we describe the effect of LPS on the biological behavior of DTSCs. We also focus on the molecular sensors, signaling pathways, and emerging players participating in the interaction of DTSCs with lipopolysaccharides. Although the scientific advances generated provide an understanding of the immunomodulatory potential of DTSCs, there are still new reflections to explore with regard to their clinical application in the treatment of oral inflammatory diseases.
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Affiliation(s)
- Beatriz A. Rodas-Junco
- CONAHCYT–Facultad de Ingeniería Química, Campus de Ciencias Exactas e Ingenierías, Universidad Autónoma de Yucatán, Periférico Norte Kilómetro 33.5, Tablaje Catastral 13615 Chuburná de Hidalgo Inn, Mérida CP 97203, Yucatán, Mexico
- Laboratorio Traslacional de Células Troncales de la Cavidad Bucal, Facultad de Odontología, Universidad Autónoma de Yucatán, Calle 61-A #492-A X Av. Itzaes Costado Sur “Parque de la Paz”, Col. Centro, Mérida CP 97000, Yucatán, Mexico;
| | - Sandra E. Hernández-Solís
- Departamento de Microbiología Oral y Biología Molecular, Facultad de Odontología, Universidad Autónoma de Yucatán, Calle 61-A #492-A X Av. Itzaes Costado Sur “Parque de la Paz”, Col. Centro, Mérida CP 97000, Yucatán, Mexico; (S.E.H.-S.); (F.R.-G.)
| | - Angelica A. Serralta-Interian
- Laboratorio Traslacional de Células Troncales de la Cavidad Bucal, Facultad de Odontología, Universidad Autónoma de Yucatán, Calle 61-A #492-A X Av. Itzaes Costado Sur “Parque de la Paz”, Col. Centro, Mérida CP 97000, Yucatán, Mexico;
- Facultad de Ingeniería Química, Campus de Ciencias Exactas e Ingenierías, Universidad Autónoma de Yucatán, Periférico Norte Kilómetro 33.5, Tablaje Catastral 13615 Chuburná de Hidalgo Inn, Mérida CP 97203, Yucatán, Mexico
| | - Florencio Rueda-Gordillo
- Departamento de Microbiología Oral y Biología Molecular, Facultad de Odontología, Universidad Autónoma de Yucatán, Calle 61-A #492-A X Av. Itzaes Costado Sur “Parque de la Paz”, Col. Centro, Mérida CP 97000, Yucatán, Mexico; (S.E.H.-S.); (F.R.-G.)
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5
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Yoon Y, Song S. Structural Insights into the Lipopolysaccharide Transport (Lpt) System as a Novel Antibiotic Target. J Microbiol 2024; 62:261-275. [PMID: 38816673 DOI: 10.1007/s12275-024-00137-w] [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: 03/19/2024] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 06/01/2024]
Abstract
Lipopolysaccharide (LPS) is a critical component of the extracellular leaflet within the bacterial outer membrane, forming an effective physical barrier against environmental threats in Gram-negative bacteria. After LPS is synthesized and matured in the bacterial cytoplasm and the inner membrane (IM), LPS is inserted into the outer membrane (OM) through the ATP-driven LPS transport (Lpt) pathway, which is an energy-intensive process. A trans-envelope complex that contains seven Lpt proteins (LptA-LptG) is crucial for extracting LPS from the IM and transporting it across the periplasm to the OM. The last step in LPS transport involves the mediation of the LptDE complex, facilitating the insertion of LPS into the outer leaflet of the OM. As the Lpt system plays an essential role in maintaining the impermeability of the OM via LPS decoration, the interactions between these interconnected subunits, which are meticulously regulated, may be potential targets for the development of new antibiotics to combat multidrug-resistant Gram-negative bacteria. In this review, we aimed to provide an overview of current research concerning the structural interactions within the Lpt system and their implications to clarify the function and regulation of LPS transport in the overall process of OM biogenesis. Additionally, we explored studies on the development of therapeutic inhibitors of LPS transport, the factors that limit success, and future prospects.
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Affiliation(s)
- Yurim Yoon
- Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology, Daejeon, 34114, Republic of Korea
| | - Saemee Song
- Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology, Daejeon, 34114, Republic of Korea.
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6
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Cina NP, Klug CS. Conformational investigation of the asymmetric periplasmic domains of E. coli LptB 2FGC using SDSL CW EPR spectroscopy. APPLIED MAGNETIC RESONANCE 2024; 55:141-158. [PMID: 38645307 PMCID: PMC11025719 DOI: 10.1007/s00723-023-01590-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 04/23/2024]
Abstract
The majority of pathogenic Gram-negative bacteria benefit from intrinsic antibiotic resistance, attributed primarily to the lipopolysaccharide (LPS) coating of the bacterial envelope. To effectively coat the bacterial cell envelope, LPS is transported from the inner membrane by the LPS transport (Lpt) system, which comprises seven distinct Lpt proteins, LptA-G, that form a stable protein bridge spanning the periplasm to connect the inner and outer membranes. The driving force of this process, LptB2FG, is an asymmetric ATP binding cassette (ABC) transporter with a novel architecture and function that ejects LPS from the inner membrane and facilitates transfer to the periplasmic bridge. Here, we utilize site-directed spin labeling (SDSL) electron paramagnetic resonance (EPR) spectroscopy to probe conformational differences between the periplasmic domains of LptF and LptG. We show that LptC solely interacts with the edge β-strand of LptF and does not directly interact with LptG. We also quantify the interaction of periplasmic LptC with LptF. Additionally, we show that LPS cannot enter the protein complex externally, supporting the unidirectional LPS transport model. Furthermore, we present our findings that the presence of LPS within the LptB2FGC binding cavity and the membrane reconstitution environment affect the structural orientation of the periplasmic domains of LptF and LptG, but overall are relatively fixed with respect to one another. This study will provide insight into the structural asymmetry associated with the newly defined type VI ABC transporter class.
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Affiliation(s)
- Nicholas P. Cina
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI 53226 USA
| | - Candice S. Klug
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI 53226 USA
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7
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Cina NP, Frank DW, Klug CS. Residues within the LptC transmembrane helix are critical for Escherichia coli LptB 2 FG ATPase regulation. Protein Sci 2024; 33:e4879. [PMID: 38131105 PMCID: PMC10804673 DOI: 10.1002/pro.4879] [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: 07/13/2023] [Revised: 11/20/2023] [Accepted: 12/19/2023] [Indexed: 12/23/2023]
Abstract
Lipopolysaccharide (LPS) synthesis in Gram-negative bacteria is completed at the outer leaflet of the inner membrane (IM). Following synthesis, seven LPS transport (Lpt) proteins facilitate the movement of LPS to the outer membrane (OM), an essential process that if disrupted at any stage has lethal effects on bacterial viability. LptB2 FG, the IM component of the Lpt bridge system, is a type VI ABC transporter that provides the driving force for LPS extraction from the IM and subsequent transport across a stable protein bridge to the outer leaflet of the OM. LptC is a periplasmic protein anchored to the IM by a single transmembrane (TM) helix intercalating within the lateral gate formed by LptF TM5 and LptG TM1. LptC facilitates the hand-off of LPS from LptB2 FG to the periplasmic protein LptA and has been shown to regulate the ATPase activity of LptB2 FG. Here, using an engineered chromosomal knockout system in Escherichia coli to assess the effects of LptC mutations in vivo, we identified six partial loss of function LptC mutations in the first unbiased alanine screen of this essential protein. To investigate the functional effects of these mutations, nanoDSF (differential scanning fluorimetry) and site-directed spin labeling (SDSL) electron paramagnetic resonance (EPR) spectroscopy in combination with an in vitro ATPase assay show that specific residues in the TM helix of LptC destabilize the LptB2 FGC complex and regulate the ATPase activity of LptB.
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Affiliation(s)
- Nicholas P. Cina
- Department of BiophysicsMedical College of WisconsinMilwaukeeWisconsinUSA
| | - Dara W. Frank
- Department of Microbiology & ImmunologyMedical College of WisconsinMilwaukeeWisconsinUSA
| | - Candice S. Klug
- Department of BiophysicsMedical College of WisconsinMilwaukeeWisconsinUSA
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Huynh DTN, Lim MC, Jaiswal RK. Modified Impedance Sensing System Determination of Virulence Characteristics of Pathogenic Bacteria Klebsiella Species. Indian J Microbiol 2023; 63:421-428. [PMID: 38031597 PMCID: PMC10682369 DOI: 10.1007/s12088-023-01112-6] [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: 02/23/2023] [Accepted: 10/10/2023] [Indexed: 12/01/2023] Open
Abstract
An impedance sensing system is a family of biosensors that measure changes in electrical impedance to perform their functions. Physical and chemical changes in the impedance of the sensing element, such as changes in the concentration of a target analyte or changes in the physical properties of the sensing element, can result in changes in the impedance of the sensing element. Many impedance biosensors have been developed for the detection of pathogens in the past few decades. Several types of biosensors have been developed for the detection of infections, including transduction elements, biorecognition components, and electrochemical approaches. In this review, we discuss the characteristics and pathogenic factors associated with 2,3-butanediol-producing Klebsiella pneumoniae collected using impedance sensors. An impedance sensing system was introduced as a great method for monitoring the virulence factors of Klebsiella spp. in situ. Klebsiella pneumoniae produces virulence factors, including capsules, lipopolysaccharides, fimbriae, and siderophores, as part of its pathogenesis. It is possible to examine virulence factors' pathogenic characteristics in vitro and in vivo using real tissues or mouse models in order to conduct experiments. For the monitoring of virulence factors in situ, a novel alternative method has been developed to mimic the environment of real tissues. For the purpose of developing tissue-mimicking models, mucin and mannose were used to modify the surface of gold electrodes. These components are known to contribute to the adhesion of pathogens to epithelial cells in mammals.
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Affiliation(s)
- Duyen Thi Ngoc Huynh
- Department of Food Science and Biotechnology and Graduate School of Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, 17104 Republic of Korea
| | - Min-Cheol Lim
- Research Group of Food Safety and Distribution, Korea Food Research Institute (KFRI), Wanju-gun, Jeollabuk-do 55365 Republic of Korea
| | - Rishi Kumar Jaiswal
- Department of Cancer Biology, Cardinal Bernardin Cancer Center, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153 USA
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Yang YM, Fu X, Cui FJ, Sun L, Zan XY, Sun WJ. Biochemical and structural characterization of a glucan synthase GFGLS2 from edible fungus Grifola frondosa to synthesize β-1, 3-glucan. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:163. [PMID: 37904199 PMCID: PMC10617128 DOI: 10.1186/s13068-023-02380-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 08/05/2023] [Indexed: 11/01/2023]
Abstract
BACKGROUND Grifola frondosa is a Basidiomycete fungus belonging to the family of Grifolaceae and the order of Polyporales. β-Glucans are the main polymers in G. frondosa, playing a crucial role in the physiology and representing the healthy benefits for humans. The membrane-integrated β-1, 3-glucan synthase (GLS) is responsible for glucan synthesis, cell wall assembly, differentiation and growth of the edible fungi. However, the structural/catalytic characteristics and mechanisms of β-1, 3-glucan synthases in G. frondosa are still unknown due to their extremely complex structures with multi-transmembranes and large molecular masses. RESULTS Herein, a β-1, 3-glucan synthase (GFGLS2) was purified and identified from the cultured mycelia with a specific activity of 60.01 pmol min-1 μg-1 for the first time. The GFGLS2 showed a strict specificity to UDP-glucose with a Vmax value of 1.29 ± 0.04 µM min-1 at pH 7.0 and synthesized β-1, 3-glucan with a maximum degree of polymerization (DP) of 62. Sequence Similarity Network (SSN) analysis revealed that GFGLS2 has a close relationship with others in Ganoderma sinense, Trametes coccinea, Polyporus brumalis, and Trametes pubescens. With the assistance of 3D structure modelling by AlphaFold 2, molecular docking and molecular dynamics simulations, the central hydrophilic domain (Class III) in GFGLS2 was the main active sites through binding the substrate UDP-glucose to 11 amino acid residues via hydrogen bonds, π-stacking and salt bridges. CONCLUSIONS The biochemical, 3D structural characterization and potential catalytic mechanism of a membrane-bound β-1, 3-glucan synthase GFGLS2 from cultured mycelia of G. frondosa were well investigated and would provide a reasonable full picture of β-1, 3-glucan synthesis in fungi.
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Affiliation(s)
- Yu-Meng Yang
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Xin Fu
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Feng-Jie Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China.
- Jiangxi Provincial Engineering and Technology Center for Food Additives Bio-Production, Dexing, 334221, China.
| | - Lei Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Xin-Yi Zan
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Wen-Jing Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
- Jiangxi Provincial Engineering and Technology Center for Food Additives Bio-Production, Dexing, 334221, China
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Yang Y, Chen H, Corey RA, Morales V, Quentin Y, Froment C, Caumont-Sarcos A, Albenne C, Burlet-Schiltz O, Ranava D, Stansfeld PJ, Marcoux J, Ieva R. LptM promotes oxidative maturation of the lipopolysaccharide translocon by substrate binding mimicry. Nat Commun 2023; 14:6368. [PMID: 37821449 PMCID: PMC10567701 DOI: 10.1038/s41467-023-42007-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 09/27/2023] [Indexed: 10/13/2023] Open
Abstract
Insertion of lipopolysaccharide (LPS) into the bacterial outer membrane (OM) is mediated by a druggable OM translocon consisting of a β-barrel membrane protein, LptD, and a lipoprotein, LptE. The β-barrel assembly machinery (BAM) assembles LptD together with LptE at the OM. In the enterobacterium Escherichia coli, formation of two native disulfide bonds in LptD controls translocon activation. Here we report the discovery of LptM (formerly YifL), a lipoprotein conserved in Enterobacteriaceae, that assembles together with LptD and LptE at the BAM complex. LptM stabilizes a conformation of LptD that can efficiently acquire native disulfide bonds, whereas its inactivation makes disulfide bond isomerization by DsbC become essential for viability. Our structural prediction and biochemical analyses indicate that LptM binds to sites in both LptD and LptE that are proposed to coordinate LPS insertion into the OM. These results suggest that, by mimicking LPS binding, LptM facilitates oxidative maturation of LptD, thereby activating the LPS translocon.
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Affiliation(s)
- Yiying Yang
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31062, France
| | - Haoxiang Chen
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31062, France
| | - Robin A Corey
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, Bristol, BS8 1TD, UK
| | - Violette Morales
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31062, France
| | - Yves Quentin
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31062, France
| | - Carine Froment
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31077, France
- Infrastructure Nationale de Protéomique, ProFI, FR 2048, Toulouse, France
| | - Anne Caumont-Sarcos
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31062, France
| | - Cécile Albenne
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31062, France
| | - Odile Burlet-Schiltz
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31077, France
- Infrastructure Nationale de Protéomique, ProFI, FR 2048, Toulouse, France
| | - David Ranava
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31062, France
| | - Phillip J Stansfeld
- School of Life Sciences and Department of Chemistry, Gibbet Hill Campus, The University of Warwick, Coventry, CV4 7AL, UK
| | - Julien Marcoux
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31077, France
- Infrastructure Nationale de Protéomique, ProFI, FR 2048, Toulouse, France
| | - Raffaele Ieva
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, 31062, France.
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Sabnis A, Edwards AM. Lipopolysaccharide as an antibiotic target. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119507. [PMID: 37268022 DOI: 10.1016/j.bbamcr.2023.119507] [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: 04/04/2022] [Revised: 04/18/2023] [Accepted: 05/14/2023] [Indexed: 06/04/2023]
Abstract
Gram-negative bacteria, including Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii are amongst the highest priority drug-resistant pathogens, for which new antibiotics are urgently needed. Whilst antibiotic drug development is inherently challenging, this is particularly true for Gram-negative bacteria due to the presence of the outer membrane, a highly selective permeability barrier that prevents the ingress of several classes of antibiotic. This selectivity is largely due to an outer leaflet composed of the glycolipid lipopolysaccharide (LPS), which is essential for the viability of almost all Gram-negative bacteria. This essentiality, coupled with the conservation of the synthetic pathway across species and recent breakthroughs in our understanding of transport and membrane homeostasis has made LPS an attractive target for novel antibiotic drug development. Several different targets have been explored and small molecules developed that show promising activity in vitro. However, these endeavours have met limited success in clinical testing and the polymyxins, discovered more than 70 years ago, remain the only LPS-targeting drugs to enter the clinic thus far. In this review, we will discuss efforts to develop therapeutic inhibitors of LPS synthesis and transport and the reasons for limited success, and explore new developments in understanding polymyxin mode of action and the identification of new analogues with reduced toxicity and enhanced activity.
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Affiliation(s)
- Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London SW7 2AZ, UK
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London SW7 2AZ, UK.
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12
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Dey J, Mahapatra SR, Singh PK, Prabhuswamimath SC, Misra N, Suar M. Designing of multi-epitope peptide vaccine against Acinetobacter baumannii through combined immunoinformatics and protein interaction-based approaches. Immunol Res 2023; 71:639-662. [PMID: 37022613 PMCID: PMC10078064 DOI: 10.1007/s12026-023-09374-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 03/16/2023] [Indexed: 04/07/2023]
Abstract
Acinetobacter baumannii is one of the major pathogenic ESKAPE bacterium, which is responsible for about more than 722,000 cases in a year, globally. Despite the alarming increase in multidrug resistance, a safe and effective vaccine for Acinetobacter infections is still not available. Hence in the current study, a multiepitope vaccine construct was developed using linear B cell, cytotoxic T cell, and helper T cell epitopes from the antigenic and well-conserved lipopolysaccharide assembly proteins employing systematic immunoinformatics and structural vaccinology strategies. The multi-peptide vaccine was predicted to be highly antigenic, non-allergenic, non-toxic, and cover maximum population coverage worldwide. Further, the vaccine construct was modeled along with adjuvant and peptide linkers and validated to achieve a high-quality three-dimensional structure which was subsequently utilized for cytokine prediction, disulfide engineering, and docking analyses with Toll-like receptor (TLR4). Ramachandran plot showed 98.3% of the residues were located in the most favorable and permitted regions, thereby corroborating the feasibility of the modeled vaccine construct. Molecular dynamics simulation for a 100 ns timeframe further confirmed the stability of the binding vaccine-receptor complex. Finally, in silico cloning and codon adaptation were also performed with the pET28a (+) plasmid vector to determine the efficiency of expression and translation of the vaccine. Immune simulation studies demonstrated that the vaccine could trigger both B and T cell responses and can elicit strong primary, secondary, and tertiary immune responses. The designed multi-peptide subunit vaccine would certainly expedite the experimental approach for the development of a vaccine against A. baumannii infection.
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Affiliation(s)
- Jyotirmayee Dey
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, -751024, Bhubaneswar, India
| | - Soumya Ranjan Mahapatra
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, -751024, Bhubaneswar, India
| | | | - Samudyata C Prabhuswamimath
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, -570015, Mysuru, Karnataka, India
| | - Namrata Misra
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, -751024, Bhubaneswar, India.
- KIIT-Technology Business Incubator (KIIT-TBI), Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, -751024, Bhubaneswar, India.
| | - Mrutyunjay Suar
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, -751024, Bhubaneswar, India.
- KIIT-Technology Business Incubator (KIIT-TBI), Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, -751024, Bhubaneswar, India.
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13
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Shi Z, Zhang X, Yang X, Zhang X, Ma F, Gan H, Chen J, Wang D, Sun W, Wang J, Wang C, Lyu L, Yang K, Deng L, Qing G. Specific Clearance of Lipopolysaccharide from Blood Based on Peptide Bottlebrush Polymer for Sepsis Therapy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302560. [PMID: 37247257 DOI: 10.1002/adma.202302560] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/16/2023] [Indexed: 05/31/2023]
Abstract
Lipopolysaccharide (LPS) is the primary bacterial toxin that is vital to the pathogenesis and progression of sepsis associated with extremely high morbidity and mortality worldwide. However, specific clearance of LPS from circulating blood is highly challenging because of the structural complexity and its variation between/within bacterial species. Herein, a robust strategy based on phage display screening and hemocompatible peptide bottlebrush polymer design for specific clearance of targeted LPS from circulating blood is proposed. Using LPS extracted from Escherichia coli as an example, a novel peptide (HWKAVNWLKPWT) with high affinity (KD < 1.0 nм), specificity, and neutralization activity (95.9 ± 0.1%) against the targeted LPS is discovered via iterative affinity selection coupled with endotoxin detoxification screening. A hemocompatible bottlebrush polymer bearing the short peptide [poly(PEGMEA-co-PEP-1)] exhibits high LPS selectivity to reduce circulating LPS level from 2.63 ± 0.01 to 0.78 ± 0.05 EU mL-1 in sepsis rabbits via extracorporeal hemoperfusion (LPS clearance ratio > 70%), reversing the LPS-induced leukocytopenia and multiple organ damages significantly. This work provides a universal paradigm for developing a highly selective hemoadsorbent library fully covering the LPS family, which is promising to create a new era of precision medicine in sepsis therapy.
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Affiliation(s)
- Zhenqiang Shi
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Xiancheng Zhang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Xijing Yang
- Animal Experiment Center, West China Hospital, Sichuan University, Chengdu, 610041, P.R. China
| | - Xiaoyu Zhang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Fei Ma
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, P.R. China
| | - Hui Gan
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, 100850, P.R. China
| | - Junjun Chen
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Dongdong Wang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Wenjing Sun
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Jingxia Wang
- Radiation Chemistry Department, Sichuan Institute of Atomic Energy, Chengdu, 610101, P.R. China
| | - Cunli Wang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Liting Lyu
- Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Kaiguang Yang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
| | - Lijing Deng
- Pediatric Intensive Care Unit, Department of Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, 610041, P.R. China
| | - Guangyan Qing
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
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14
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Elshenawi Y, Hu S, Hathroubi S. Biofilm of Helicobacter pylori: Life Cycle, Features, and Treatment Options. Antibiotics (Basel) 2023; 12:1260. [PMID: 37627679 PMCID: PMC10451559 DOI: 10.3390/antibiotics12081260] [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: 06/29/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
Helicobacter pylori is a gastric pathogen that infects nearly half of the global population and is recognized as a group 1 carcinogen by the Word Health Organization. The global rise in antibiotic resistance has increased clinical challenges in treating H. pylori infections. Biofilm growth has been proposed to contribute to H. pylori's chronic colonization of the host stomach, treatment failures, and the eventual development of gastric diseases. Several components of H. pylori have been identified to promote biofilm growth, and several of these may also facilitate antibiotic tolerance, including the extracellular matrix, outer membrane proteins, shifted morphology, modulated metabolism, efflux pumps, and virulence factors. Recent developments in therapeutic approaches targeting H. pylori biofilm have shown that synthetic compounds, such as small molecule drugs and plant-derived compounds, are effective at eradicating H. pylori biofilms. These combined topics highlight the necessity for biofilm-based research in H. pylori, to improve current H. pylori-targeted therapeutic approaches and alleviate relative public health burden. In this review we discuss recent discoveries that have decoded the life cycle of H. pylori biofilms and current biofilm-targeted treatment strategies.
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Affiliation(s)
- Yasmine Elshenawi
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA;
| | - Shuai Hu
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA;
| | - Skander Hathroubi
- Spartha Medical, CRBS 1 Rue Eugène Boeckel, 67000 Strasbourg, France
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15
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Jensen SJ, Ruhe ZC, Williams AF, Nhan DQ, Garza-Sánchez F, Low DA, Hayes CS. Paradoxical Activation of a Type VI Secretion System Phospholipase Effector by Its Cognate Immunity Protein. J Bacteriol 2023; 205:e0011323. [PMID: 37212679 PMCID: PMC10294671 DOI: 10.1128/jb.00113-23] [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: 03/27/2023] [Accepted: 05/03/2023] [Indexed: 05/23/2023] Open
Abstract
Type VI secretion systems (T6SSs) deliver cytotoxic effector proteins into target bacteria and eukaryotic host cells. Antibacterial effectors are invariably encoded with cognate immunity proteins that protect the producing cell from self-intoxication. Here, we identify transposon insertions that disrupt the tli immunity gene of Enterobacter cloacae and induce autopermeabilization through unopposed activity of the Tle phospholipase effector. This hyperpermeability phenotype is T6SS dependent, indicating that the mutants are intoxicated by Tle delivered from neighboring sibling cells rather than by internally produced phospholipase. Unexpectedly, an in-frame deletion of tli does not induce hyperpermeability because Δtli null mutants fail to deploy active Tle. Instead, the most striking phenotypes are associated with disruption of the tli lipoprotein signal sequence, which prevents immunity protein localization to the periplasm. Immunoblotting reveals that most hyperpermeable mutants still produce Tli, presumably from alternative translation initiation codons downstream of the signal sequence. These observations suggest that cytosolic Tli is required for the activation and/or export of Tle. We show that Tle growth inhibition activity remains Tli dependent when phospholipase delivery into target bacteria is ensured through fusion to the VgrG β-spike protein. Together, these findings indicate that Tli has distinct functions, depending on its subcellular localization. Periplasmic Tli acts as a canonical immunity factor to neutralize incoming effector proteins, while a cytosolic pool of Tli is required to activate the phospholipase domain of Tle prior to T6SS-dependent export. IMPORTANCE Gram-negative bacteria use type VI secretion systems deliver toxic effector proteins directly into neighboring competitors. Secreting cells also produce specific immunity proteins that neutralize effector activities to prevent autointoxication. Here, we show the Tli immunity protein of Enterobacter cloacae has two distinct functions, depending on its subcellular localization. Periplasmic Tli acts as a canonical immunity factor to block Tle lipase effector activity, while cytoplasmic Tli is required to activate the lipase prior to export. These results indicate Tle interacts transiently with its cognate immunity protein to promote effector protein folding and/or packaging into the secretion apparatus.
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Affiliation(s)
- Steven J. Jensen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Zachary C. Ruhe
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - August F. Williams
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Dinh Q. Nhan
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Fernando Garza-Sánchez
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
| | - David A. Low
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
- Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Christopher S. Hayes
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
- Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, California, USA
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16
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He H, Pramanik AS, Swanson SK, Johnson DK, Florens L, Zückert WR. A Borrelia burgdorferi LptD homolog is required for flipping of surface lipoproteins through the spirochetal outer membrane. Mol Microbiol 2023; 119:752-767. [PMID: 37170643 PMCID: PMC10330739 DOI: 10.1111/mmi.15072] [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: 12/21/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/13/2023]
Abstract
Borrelia spirochetes are unique among diderm bacteria in their lack of lipopolysaccharide (LPS) in the outer membrane (OM) and their abundance of surface-exposed lipoproteins with major roles in transmission, virulence, and pathogenesis. Despite their importance, little is known about how surface lipoproteins are translocated through the periplasm and the OM. Here, we characterized Borrelia burgdorferi BB0838, a distant homolog of the OM LPS assembly protein LptD. Using a CRISPR interference approach, we showed that BB0838 is required for cell growth and envelope stability. Upon BB0838 knockdown, surface lipoprotein OspA was retained in the inner leaflet of the OM, as determined by its inaccessibility to in situ proteolysis but its presence in OM vesicles. The topology of the OM porin/adhesin P66 remained unaffected. Quantitative mass spectrometry of the B. burgdorferi membrane-associated proteome confirmed the selective periplasmic retention of surface lipoproteins under BB0838 knockdown conditions. Additional analysis identified a single in situ protease-accessible BB0838 peptide that mapped to a predicted β-barrel surface loop. Alphafold Multimer modeled a B. burgdorferi LptB2 FGCAD complex spanning the periplasm. Together, this suggests that BB0838/LptDBb facilitates the essential terminal step in spirochetal surface lipoprotein secretion, using an orthologous OM component of a pathway that secretes LPS in proteobacteria.
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Affiliation(s)
- Huan He
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
| | - Ankita S. Pramanik
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
| | | | - David K. Johnson
- University of Kansas, Computational Chemical Biology Core, Lawrence, Kansas, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Wolfram R. Zückert
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
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17
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McDonnell RT, Patel N, Wehrspan ZJ, Elcock AH. Atomic Models of All Major Trans-Envelope Complexes Involved in Lipid Trafficking in Escherichia Coli Constructed Using a Combination of AlphaFold2, AF2Complex, and Membrane Morphing Simulations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.28.538765. [PMID: 37162969 PMCID: PMC10168319 DOI: 10.1101/2023.04.28.538765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In Gram-negative bacteria, several trans-envelope complexes (TECs) have been identified that span the periplasmic space in order to facilitate lipid transport between the inner- and outer- membranes. While partial or near-complete structures of some of these TECs have been solved by conventional experimental techniques, most remain incomplete. Here we describe how a combination of computational approaches, constrained by experimental data, can be used to build complete atomic models for four TECs implicated in lipid transport in Escherichia coli . We use DeepMind's protein structure prediction algorithm, AlphaFold2, and a variant of it designed to predict protein complexes, AF2Complex, to predict the oligomeric states of key components of TECs and their likely interfaces with other components. After obtaining initial models of the complete TECs by superimposing predicted structures of subcomplexes, we use the membrane orientation prediction algorithm OPM to predict the likely orientations of the inner- and outer- membrane components in each TEC. Since, in all cases, the predicted membrane orientations in these initial models are tilted relative to each other, we devise a novel molecular mechanics-based strategy that we call "membrane morphing" that adjusts each TEC model until the two membranes are properly aligned with each other and separated by a distance consistent with estimates of the periplasmic width in E. coli . The study highlights the potential power of combining computational methods, operating within limits set by both experimental data and by cell physiology, for producing useable atomic structures of very large protein complexes.
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18
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Wikantyasning ER, Da’i M, Cholisoh Z, Kalsum U. 3-Aminophenylboronic Acid Conjugation on Responsive Polymer and Gold Nanoparticles for Qualitative Bacterial Detection. JOURNAL OF PHARMACY AND BIOALLIED SCIENCES 2023; 15:81-87. [PMID: 37469647 PMCID: PMC10353662 DOI: 10.4103/jpbs.jpbs_646_22] [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: 12/13/2022] [Revised: 03/07/2023] [Accepted: 04/08/2023] [Indexed: 07/21/2023] Open
Abstract
Background Because of their sensitive and selective responses to a wide variety of analytes, colorimetric sensors have gained widespread acceptance in recent years. Gold nanoparticles (AuNPs) are widely employed in visual sensor strategies due to their high stability and ease of use. Combining AuNPs with a responsive polymer can result in distinct surface plasmon resonance (SPR) changes that can be utilized as colorimetric biosensors. Objectives The purpose of this research is to develop a colorimetric-based sensor through the utilization of the optical properties of gold nanoparticles (AuNPs) crosslinked with pH-responsive polymers poly (acrylic acid) (PAA) conjugated to 3-aminophenyl boronic acid (APBA). Methods The polymer (PAA) was synthesized via RAFT polymerization. The inversed Turkevic method was used to produce AuNPs, which were subsequently used in a self-assembly process using poly (acrylic acid)-aminophenyl boronic acid (PAA-APBA) to create the self-assembled AuNPs-APBA-PAA. The particle size, zeta potential, and reversibility of the polymer-modified gold nanoparticles were determined using a transmission electron microscope (TEM), a particle size analyzer (PSA), and an Ultraviolet-Visible spectrophotometer (UV-Vis spectrophotometer). Visual, UV-Vis spectrophotometer and TEM observations confirmed the system's ability to identify bacteria. Statistical analysis was performed using a one-way analysis of variance using Excel software. Results Using UV-Vis spectrophotometry, the particle size of AuNPs was determined to be 25.7 nm, and the maximum absorbance occurred at 530 nm. AuNPs PAA APBA colloid exhibited an absorbance maximum of 532 nm, a zeta potential of -41.53, and a pH transition point between 4 and 5. At E. coli concentrations of 4.5 x 107 CFU/mL, the color of the system sensors changed from red to blue after 15 hours of incubation, whereas at S. aureus concentrations of 1.2 x 109 CFU/mL, the color changed to purple immediately after mixing. The TEM confirmed that the detection mechanism is based on the boronate-polyol bonding of saccharides on the outer membranes of Escherichia coli and Staphylococcus aureus. Conclusions The use of APBA in conjunction with pH-responsive PAA polymers containing AuNPs to detect E. coli and S. aureus bacteria induces a maximum wavelength transition, followed by a color change from red to blue. By the process of de-swelling of the responsive polymer, which induces the aggregation of the AuNPs, the established sensor system is able to alter the color. The conjugated polymer and gold nanoparticle-based sensor system demonstrated a promising method for bacterial detection.
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Affiliation(s)
| | - Muhammad Da’i
- Faculty of Pharmacy, Universitas Muhammadiyah Surakarta, Jl. A. Yani 157, Sukoharjo, Indonesia
| | - Zakky Cholisoh
- Faculty of Pharmacy, Universitas Muhammadiyah Surakarta, Jl. A. Yani 157, Sukoharjo, Indonesia
| | - Ummi Kalsum
- Study Program of Pharmacy, STIKES Telogorejo, Jl. Yos Sudarso, Semarang, Jawa Tengah, Indonesia
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19
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Jensen SJ, Ruhe ZC, Williams AF, Nhan DQ, Garza-Sánchez F, Low DA, Hayes CS. Paradoxical activation of a type VI secretion system (T6SS) phospholipase effector by its cognate immunity protein. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534661. [PMID: 37034769 PMCID: PMC10081291 DOI: 10.1101/2023.03.28.534661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Type VI secretion systems (T6SS) deliver cytotoxic effector proteins into target bacteria and eukaryotic host cells. Antibacterial effectors are invariably encoded with cognate immunity proteins that protect the producing cell from self-intoxication. Here, we identify transposon insertions that disrupt the tli immunity gene of Enterobacter cloacae and induce auto-permeabilization through unopposed activity of the Tle phospholipase effector. This hyper-permeability phenotype is T6SS-dependent, indicating that the mutants are intoxicated by Tle delivered from neighboring sibling cells rather than by internally produced phospholipase. Unexpectedly, an in-frame deletion of tli does not induce hyper-permeability because Δ tli null mutants fail to deploy active Tle. Instead, the most striking phenotypes are associated with disruption of the tli lipoprotein signal sequence, which prevents immunity protein localization to the periplasm. Immunoblotting reveals that most hyper-permeable mutants still produce Tli, presumably from alternative translation initiation codons downstream of the signal sequence. These observations suggest that cytosolic Tli is required for the activation and/or export of Tle. We show that Tle growth inhibition activity remains Tli-dependent when phospholipase delivery into target bacteria is ensured through fusion to the VgrG β-spike protein. Together, these findings indicate that Tli has distinct functions depending on its subcellular localization. Periplasmic Tli acts as a canonical immunity factor to neutralize incoming effector proteins, while a cytosolic pool of Tli is required to activate the phospholipase domain of Tle prior to T6SS-dependent export.
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20
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Bilsing FL, Anlauf MT, Hachani E, Khosa S, Schmitt L. ABC Transporters in Bacterial Nanomachineries. Int J Mol Sci 2023; 24:ijms24076227. [PMID: 37047196 PMCID: PMC10094684 DOI: 10.3390/ijms24076227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/18/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Members of the superfamily of ABC transporters are found in all domains of life. Most of these primary active transporters act as isolated entities and export or import their substrates in an ATP-dependent manner across biological membranes. However, some ABC transporters are also part of larger protein complexes, so-called nanomachineries that catalyze the vectorial transport of their substrates. Here, we will focus on four bacterial examples of such nanomachineries: the Mac system providing drug resistance, the Lpt system catalyzing vectorial LPS transport, the Mla system responsible for phospholipid transport, and the Lol system, which is required for lipoprotein transport to the outer membrane of Gram-negative bacteria. For all four systems, we tried to summarize the existing data and provide a structure-function analysis highlighting the mechanistical aspect of the coupling of ATP hydrolysis to substrate translocation.
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21
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Miyazaki R, Akiyama Y. Analyzing protein intermediate interactions in living E. coli cells using site-specific photo-crosslinking combined with chemical crosslinking. STAR Protoc 2023; 4:102178. [PMID: 36933223 PMCID: PMC10034496 DOI: 10.1016/j.xpro.2023.102178] [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: 12/26/2022] [Revised: 01/31/2023] [Accepted: 02/23/2023] [Indexed: 03/19/2023] Open
Abstract
Information on protein-protein interactions is crucial in understanding protein-mediated cellular processes; however, analyzing transient and unstable interactions in living cells is challenging. Here, we present a protocol capturing the interaction between an assembly intermediate form of a bacterial outer membrane protein and β-barrel assembly machinery complex components. We describe steps for expression of a protein target, chemical crosslinking combined with in vivo photo-crosslinking and crosslinking detection procedures including immunoblotting. This protocol can be adapted to analyze interprotein interactions in other processes. For complete details on the use and execution of this protocol, please refer to Miyazaki et al. (2021).1.
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Affiliation(s)
- Ryoji Miyazaki
- Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
| | - Yoshinori Akiyama
- Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
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22
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Romano K, Hung D. Targeting LPS biosynthesis and transport in gram-negative bacteria in the era of multi-drug resistance. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119407. [PMID: 36543281 PMCID: PMC9922520 DOI: 10.1016/j.bbamcr.2022.119407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 11/09/2022] [Accepted: 11/18/2022] [Indexed: 12/23/2022]
Abstract
Gram-negative bacteria pose a major threat to human health in an era fraught with multi-drug resistant bacterial infections. Despite extensive drug discovery campaigns over the past decades, no new antibiotic target class effective against gram-negative bacteria has become available to patients since the advent of the carbapenems in 1985. Antibiotic discovery efforts against gram-negative bacteria have been hampered by limited intracellular accumulation of xenobiotics, in large part due to the impermeable cell envelope comprising lipopolysaccharide (LPS) in the outer leaflet of the outer membrane, as well as a panoply of efflux pumps. The biosynthesis and transport of LPS are essential to the viability and virulence of most gram-negative bacteria. Thus, both LPS biosynthesis and transport are attractive pathways to target therapeutically. In this review, we summarize the LPS biosynthesis and transport pathways and discuss efforts to find small molecule inhibitors against targets within these pathways.
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Affiliation(s)
- K.P. Romano
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, MA, USA,The Broad Institute of MIT and Harvard, Cambridge, MA, USA,Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA
| | - D.T. Hung
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA,Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA,Department of Genetics, Harvard Medical School, Boston, MA, USA,Corresponding author at: The Broad Institute of MIT and Harvard, Cambridge, MA, USA. (D.T. Hung)
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23
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Suppressor Mutations in LptF Bypass Essentiality of LptC by Forming a Six-Protein Transenvelope Bridge That Efficiently Transports Lipopolysaccharide. mBio 2023; 14:e0220222. [PMID: 36541759 PMCID: PMC9972910 DOI: 10.1128/mbio.02202-22] [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] [Indexed: 12/24/2022] Open
Abstract
Lipopolysaccharide (LPS) is an essential component of the outer membrane (OM) of many Gram-negative bacteria, providing a barrier against the entry of toxic molecules. In Escherichia coli, LPS is exported to the cell surface by seven essential proteins (LptA-G) that form a transenvelope complex. At the inner membrane, the ATP-binding cassette (ABC) transporter LptB2FG associates with LptC to power LPS extraction from the membrane and transfer to the periplasmic LptA protein, which is in complex with the OM translocon LptDE. LptC interacts both with LptB2FG and LptADE to mediate the formation of the transenvelope bridge and regulates the ATPase activity of LptB2FG. A genetic screen has previously identified suppressor mutants at a residue (R212) of LptF that are viable in the absence of LptC. Here, we present in vivo evidence that the LptF R212G mutant assembles a six-protein transenvelope complex in which LptA mediates interactions with LptF and LptD in the absence of LptC. Furthermore, we present in vitro evidence that the mutant LptB2FG complexes restore the regulation of ATP hydrolysis as it occurs in the LptB2FGC complex to achieve wild-type efficient coupling of ATP hydrolysis and LPS movement. We also show the suppressor mutations restore the wild-type levels of LPS transport both in vivo and in vitro, but remarkably, without restoring the affinity of the inner membrane complex for LptA. Based on the sensitivity of lptF suppressor mutants to selected stress conditions relative to wild-type cells, we show that there are additional regulatory functions of LptF and LptC that had not been identified. IMPORTANCE The presence of an external LPS layer in the outer membrane makes Gram-negative bacteria intrinsically resistant to many antibiotics. Millions of LPS molecules are transported to the cell surface per generation by the Lpt molecular machine made, in E. coli, by seven essential proteins. LptC is the unconventional regulatory subunit of the LptB2FGC ABC transporter, involved in coordinating energy production and LPS transport. Surprisingly, despite being essential for bacterial growth, LptC can be deleted, provided that a specific residue in the periplasmic domain of LptF is mutated and LptA is overexpressed. Here, we apply biochemical techniques to investigate the suppression mechanism. The data produced in this work disclose an unknown regulatory function of LptF in the transporter that not only expands the knowledge about the Lpt complex but can also be targeted by novel LPS biogenesis inhibitors.
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Sperandeo P, Martorana AM, Zaccaria M, Polissi A. Targeting the LPS export pathway for the development of novel therapeutics. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119406. [PMID: 36473551 DOI: 10.1016/j.bbamcr.2022.119406] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 10/14/2022] [Accepted: 11/01/2022] [Indexed: 12/12/2022]
Abstract
The rapid rise of multi-resistant bacteria is a global health threat. This is especially serious for Gram-negative bacteria in which the impermeable outer membrane (OM) acts as a shield against antibiotics. The development of new drugs with novel modes of actions to combat multi-drug resistant pathogens requires the selection of suitable processes to be targeted. The LPS export pathway is an excellent under exploited target for drug development. Indeed, LPS is the major determinant of the OM permeability barrier, and its biogenetic pathway is conserved in most Gram-negatives. Here we describe efforts to identify inhibitors of the multiprotein Lpt system that transports LPS to the cell surface. Despite none of these molecules has been approved for clinical use, they may represent valuable compounds for optimization. Finally, the recent discovery of a link between inhibition of LPS biogenesis and changes in peptidoglycan structure uncovers additional targets to develop novel therapeutic strategies.
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Affiliation(s)
- Paola Sperandeo
- Department of Pharmacological and Biomolecular Sciences, Via Balzaretti 9, 20133 Milano, Italy
| | - Alessandra M Martorana
- Department of Pharmacological and Biomolecular Sciences, Via Balzaretti 9, 20133 Milano, Italy
| | - Marta Zaccaria
- Department of Pharmacological and Biomolecular Sciences, Via Balzaretti 9, 20133 Milano, Italy
| | - Alessandra Polissi
- Department of Pharmacological and Biomolecular Sciences, Via Balzaretti 9, 20133 Milano, Italy.
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25
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Liu X, Li P, Yan K, Du Y, Peng K, Li M, Cui K, Zhang H, Yang X, Lu S, Liang X. Resveratrol ameliorates the defects of meiotic maturation in lipopolysaccharide exposed porcine oocytes. Reprod Toxicol 2023; 115:85-93. [PMID: 36549457 DOI: 10.1016/j.reprotox.2022.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/27/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022]
Abstract
Lipopolysaccharide (LPS), a significant virulence factor of gram-negative bacteria, adversely affects female reproduction, especially the maturation and early embryonic development of oocytes, through inducing of inflammatory and oxidative stress-associated toxic responses. Resveratrol (Res), a potent antioxidant, exhibits many beneficial effects on the maturation and developmental competence of oocytes. However, it is unclear whether Res can restore LPS-induced defects in the maturation of oocytes during meiosis. In this study, we used porcine oocytes to explore the protective effects of Res and its underlying mechanism against the toxic impacts of LPS exposure on meiotic maturation and developmental competence of oocytes during meiosis. The oocytes were randomly assigned to a control, LPS-exposed or Res-supplemented group. Nuclear and cytoplasmic maturation was assessed after 26 h (MI) or 44 h (MII) of in vitro maturation (IVM). Our results showed that 10 µM Res significantly improved the rates of oocyte maturation and blastocyst formation after exposure to 15 µg/mL LPS. In addition, Res preserved the normal spindle/chromosome structure and maintained acetylated tubulin levels, actin polymerization and cortical granules (CGs) distribution. Additionally, Res protected mitochondrial content and function, scavenges reactive oxygen species (ROS), and reduced DNA damage and apoptosis in LPS-exposed oocytes. Furthermore, inhibition of SIRT1 by its specific inhibitor EX527 suppressed the recovery of ROS levels, mitochondrial content, and spindle/chromosome structure by Res supplementation. In summary, this study shows that Res can alleviate the impacts of LPS-induced toxicity on meiosis in porcine oocytes by upregulating SIRT1, which ameliorates oxidative stress and increasing mitochondrial content.
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Affiliation(s)
- Xinxin Liu
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Pan Li
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Ke Yan
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Ya Du
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Ke Peng
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Mengqi Li
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Kexin Cui
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Hengye Zhang
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Xiaogan Yang
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China
| | - Shengsheng Lu
- Agri-animal Industrial Development Institute, Guangxi University, Nanning, Guangxi 530004, China.
| | - Xingwei Liang
- College of Animal Science & Technology, Guangxi University, Nanning, Guangxi 530004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi 530004, China.
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26
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Webby MN, Oluwole AO, Pedebos C, Inns PG, Olerinyova A, Prakaash D, Housden NG, Benn G, Sun D, Hoogenboom BW, Kukura P, Mohammed S, Robinson CV, Khalid S, Kleanthous C. Lipids mediate supramolecular outer membrane protein assembly in bacteria. SCIENCE ADVANCES 2022; 8:eadc9566. [PMID: 36322653 PMCID: PMC9629720 DOI: 10.1126/sciadv.adc9566] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
β Barrel outer membrane proteins (OMPs) cluster into supramolecular assemblies that give function to the outer membrane (OM) of Gram-negative bacteria. How such assemblies form is unknown. Here, through photoactivatable cross-linking into the Escherichia coli OM, coupled with simulations, and biochemical and biophysical analysis, we uncover the basis for OMP clustering in vivo. OMPs are typically surrounded by an annular shell of asymmetric lipids that mediate higher-order complexes with neighboring OMPs. OMP assemblies center on the abundant porins OmpF and OmpC, against which low-abundance monomeric β barrels, such as TonB-dependent transporters, are packed. Our study reveals OMP-lipid-OMP complexes to be the basic unit of supramolecular OMP assembly that, by extending across the entire cell surface, couples the requisite multifunctionality of the OM to its stability and impermeability.
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Affiliation(s)
- Melissa N. Webby
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Abraham O. Oluwole
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
- The Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QZ, UK
| | - Conrado Pedebos
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Patrick G. Inns
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Anna Olerinyova
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Dheeraj Prakaash
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Nicholas G. Housden
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Georgina Benn
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Dawei Sun
- Structural Biology, Genentech Inc., South San Francisco, USA
| | - Bart W. Hoogenboom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
- Department of Physics and Astronomy, University College London, WC1E 6BT London, UK
| | - Philipp Kukura
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Shabaz Mohammed
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3QZ, UK
- Mechanistic Proteomics, Rosalind Franklin Institute, Harwell Campus, Didcot OX11 OFA, UK
| | - Carol V. Robinson
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
- The Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QZ, UK
| | - Syma Khalid
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Colin Kleanthous
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
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27
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Dai X, Yuan M, Lu Y, Zhu X, Liu C, Zheng Y, Si S, Yuan L, Zhang J, Li Y. Identification of a Small Molecule That Inhibits the Interaction of LPS Transporters LptA and LptC. Antibiotics (Basel) 2022; 11:1385. [PMID: 36290043 PMCID: PMC9598311 DOI: 10.3390/antibiotics11101385] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 10/15/2023] Open
Abstract
The need for novel antibiotics has become imperative with the increasing prevalence of antibiotic resistance in Gram-negative bacteria in clinics. Acting as a permeability barrier, lipopolysaccharide (LPS) protects Gram-negative bacteria against drugs. LPS is synthesized in cells and transported to the outer membrane (OM) via seven lipopolysaccharide transport (Lpt) proteins (LptA-LptG). Of these seven Lpt proteins, LptC interacts with LptA to transfer LPS from the inner membrane (IM) to the OM, and assembly is aided by LptD/LptE. This interaction among the Lpt proteins is important for the biosynthesis of LPS; therefore, the Lpt proteins, which are significant in the assembly process of LPS, can be a potential target for new antibiotics. In this study, a yeast two-hybrid (Y2H) system was used to screen compounds that could block LPS transport by inhibiting LptA/LptC interaction, which finally disrupts the biosynthesis of the OM. We selected the compound IMB-0042 for this study. Our results suggest that IMB-0042 disrupts LptA/LptC interaction by binding to both LptA and LptC. Escherichia coli cells, when treated with IMB-0042, showed filament morphology, impaired OM integrity, and an accumulation of LPS in the periplasm. IMB-0042 inhibited the growth of Gram-negative bacteria and showed synergistic sensitization to other antibiotics, with low cytotoxicity. Thus, we successfully identified a potential antibacterial agent by using a Y2H system, which blocks the transport of LPS by targeting LptA/LptC interaction in Escherichia coli.
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Affiliation(s)
- Xiaowei Dai
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- Hebei Key Laboratory for Chronic Diseases, Tangshan Key Laboratory for Preclinical and Basic Research on Chronic Diseases, School of Basic Medical Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Min Yuan
- State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Yu Lu
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- Hebei Key Laboratory for Chronic Diseases, Tangshan Key Laboratory for Preclinical and Basic Research on Chronic Diseases, School of Basic Medical Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Xiaohong Zhu
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Chao Liu
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yifan Zheng
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Shuyi Si
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Lijie Yuan
- Hebei Key Laboratory for Chronic Diseases, Tangshan Key Laboratory for Preclinical and Basic Research on Chronic Diseases, School of Basic Medical Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Jing Zhang
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yan Li
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
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28
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Giacometti SI, MacRae MR, Dancel-Manning K, Bhabha G, Ekiert DC. Lipid Transport Across Bacterial Membranes. Annu Rev Cell Dev Biol 2022; 38:125-153. [PMID: 35850151 DOI: 10.1146/annurev-cellbio-120420-022914] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The movement of lipids within and between membranes in bacteria is essential for building and maintaining the bacterial cell envelope. Moving lipids to their final destination is often energetically unfavorable and does not readily occur spontaneously. Bacteria have evolved several protein-mediated transport systems that bind specific lipid substrates and catalyze the transport of lipids across membranes and from one membrane to another. Specific protein flippases act in translocating lipids across the plasma membrane, overcoming the obstacle of moving relatively large and chemically diverse lipids between leaflets of the bilayer. Active transporters found in double-membraned bacteria have evolved sophisticated mechanisms to traffic lipids between the two membranes, including assembling to form large, multiprotein complexes that resemble bridges, shuttles, and tunnels, shielding lipids from the hydrophilic environment of the periplasm during transport. In this review, we explore our current understanding of the mechanisms thought to drive bacterial lipid transport.
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Affiliation(s)
- Sabrina I Giacometti
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA; , , ,
| | - Mark R MacRae
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA; , , ,
| | - Kristen Dancel-Manning
- Office of Science and Research, New York University School of Medicine, New York, NY, USA;
| | - Gira Bhabha
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA; , , ,
| | - Damian C Ekiert
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA; , , ,
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
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29
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Zhao W, Liu Y, Zhang P, Zhou P, Wu Z, Lou B, Jiang Y, Shakoor N, Li M, Li Y, Lynch I, Rui Y, Tan Z. Engineered Zn-based nano-pesticides as an opportunity for treatment of phytopathogens in agriculture. NANOIMPACT 2022; 28:100420. [PMID: 36038133 DOI: 10.1016/j.impact.2022.100420] [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: 06/03/2022] [Revised: 08/15/2022] [Accepted: 08/21/2022] [Indexed: 06/15/2023]
Abstract
People's desire for food has never slowed, despite the deterioration of the global agricultural environment and the threat to food security. People rely on agrochemicals to ensure normal crop growth and to relieve the existing demand pressure. Phytopathogens have acquired resistance to traditional pesticides as a result of pesticdes' abuse. Compared with traditional formulations, nano-pesticides have superior antimicrobial performance and are environmentally friendly. Zn-based nanoparticles (NPs) have shown their potential as strong antipathogen activity. However, their full potential has not been demonstrated yet. Here, we analyzed the prerequisites for the use of Zn-based NPs as nano-pesticides in agriculture including both intrinsic properties of the materials and environmental conditions. We also summarized the mechanisms of Zn-based NPs against phytopathogens including direct and indirect strategies to alleviate plant disease stress. Finally, the current challenges and future directions are highlighted to advance our understanding of this field and guide future studies.
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Affiliation(s)
- Weichen Zhao
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yanwanjing Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, Zhejiang Province, China
| | - Peng Zhang
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Pingfan Zhou
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Zhangguo Wu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, Zhejiang Province, China
| | - Benzhen Lou
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Yaqi Jiang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Noman Shakoor
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Mingshu Li
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Yuanbo Li
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Iseult Lynch
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Yukui Rui
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; China Agricultural University Professor Workstation of Yuhuangmiao Town, Shanghe County, Jinan, Shandong, China; China Agricultural University Professor Workstation of Sunji Town, Shanghe County, Jinan, Shandong, China.
| | - Zhiqiang Tan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, Zhejiang Province, China.
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30
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Fu X, Zan XY, Sun L, Tan M, Cui FJ, Liang YY, Meng LJ, Sun WJ. Functional Characterization and Structural Basis of the β-1,3-Glucan Synthase CMGLS from Mushroom Cordyceps militaris. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:8725-8737. [PMID: 35816703 DOI: 10.1021/acs.jafc.2c03410] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
β-1,3-Glucan synthases play key roles in glucan synthesis, cell wall assembly, and growth of fungi. However, their multi-transmembrane domains (over 14 TMHs) and large molecular masses (over 100 kDa) significantly hamper understanding of their catalytic characteristics and mechanisms. In the present study, the 5841-bp gene CMGLS encoding the 221.7 kDa membrane-bound β-1,3-glucan synthase CMGLS in Cordyceps militaris was cloned, identified, and structurally analyzed. CMGLS was partially purified with a specific activity of 87.72 pmol/min/μg, a purification fold of 121, and a yield of 10.16% using a product-entrapment purification method. CMGLS showed a strict specificity to UDP-glucose with a Km value of 84.28 μM at pH 7.0 and synthesized β-1,3-glucan with a maximum degree of polymerization (DP) of 70. With the assistance of AlphaFold and molecular docking, the 3D structure of CMGLS and its binding features with substrate UDP-glucose were proposed for the first time to our knowledge. UDP-glucose potentially bound to at least 11 residues via hydrogen bonds, π-stacking ,and salt bridges, and Arg 1436 was predicted as a key residue directly interacting with the moieties of glucose, phosphate, and the ribose ring on UDP-glucose. These findings would open an avenue to recognize and understand the glucan synthesis process and catalytic mechanism of β-1,3-glucan synthases in mushrooms.
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Affiliation(s)
- Xin Fu
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Xin-Yi Zan
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Lei Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Ming Tan
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Feng-Jie Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
- Jiangxi Provincial Engineering and Technology Center for Food Additives Bio-production, Dexing 334221, P.R. China
| | - Ying-Ying Liang
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Li-Juan Meng
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Wen-Jing Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
- Jiangxi Provincial Engineering and Technology Center for Food Additives Bio-production, Dexing 334221, P.R. China
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31
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Wilson A, Ruiz N. The transmembrane α-helix of LptC participates in LPS extraction by the LptB 2 FGC transporter. Mol Microbiol 2022; 118:61-76. [PMID: 35678757 PMCID: PMC9544173 DOI: 10.1111/mmi.14952] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/28/2022]
Abstract
Lipopolysaccharide (LPS) is an essential component of the outer membrane of most Gram‐negative bacteria that provides resistance to various toxic compounds and antibiotics. Newly synthesized LPS is extracted from the inner membrane by the ATP‐binding cassette (ABC) transporter LptB2FGC, which places the glycolipid onto a periplasmic protein bridge that connects to the outer membrane. This ABC transporter is structurally unusual in that it associates with an additional protein, LptC. The periplasmic domain of LptC is part of the transporter's bridge while its transmembrane α‐helix intercalates into the LPS‐binding cavity of the core LptB2FG transporter. LptC’s transmembrane helix affects the in vitro ATPase activity of LptB2FG, but its role in LPS transport in cells remains undefined. Here, we describe two roles of LptC’s transmembrane helix in Escherichia coli. We demonstrate that it is required to maintain proper levels of LptC and participates in coupling the activity of the ATPase LptB to that of its transmembrane partners LptF/LptG prior to loading LPS onto the periplasmic bridge. Our data support a model in which the association of LptC’s transmembrane helix with LptFG creates a nonessential step that slows down the LPS transporter.
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Affiliation(s)
- Andrew Wilson
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Natividad Ruiz
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
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32
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Fang M, Xue Z, He L, You Y, Gong Y, Fan D, Sun L, Zhai K, Yang Y, Zhang J. Distribution characteristics of the sabA, hofC, homA, homB and frpB-4 genes of Helicobacter pylori in different regions of China. PLoS One 2022; 17:e0268373. [PMID: 35588168 PMCID: PMC9119684 DOI: 10.1371/journal.pone.0268373] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/28/2022] [Indexed: 11/18/2022] Open
Abstract
Background Helicobacter pylori (H. pylori) encodes numerous outer membrane proteins (OMPs), with considerable geographic heterogeneity and related to different clinical outcomes. This study aimed to investigate the distribution characteristics of five important OMP genes (sabA, hofC, homA, homB and frpB-4) in different regions of China. Materials and method A total of 266 strains were isolated from 348 stomach biopsy specimens in Shandong, Guangxi, Heilongjiang, Hunan, and Qinghai provinces. The presence of sabA, hofC, homA, homB and frpB-4 gene was detected by polymerase chain reaction (PCR) from H. pylori genomic DNA. Results Among the strains in five regions, the prevalence of frpB-4 was 100% and that of hofC was 97.7%. The prevalence of homB in the isolates from Qinghai (45.5%) was significantly lower than that in Shandong (75.3%), Guangxi (76.9%) and Hunan (69.6%) (P<0.05). The frequency of homA in Shandong (30.1%) was significantly lower than in Guangxi (57.7%) and Qinghai (63.6%) (P<0.05). The prevalence of the sabA gene in Shandong, Guangxi, Heilongjiang, Hunan and Qinghai provinces was 21.9%, 59.7%, 45.9%, 52.2%, and 18.2%, respectively (P<0.05). The sabA “on” status was significantly more frequent in isolates from Guangxi (46.8%), Heilongjiang (37.8%), and Hunan (47.8%) than Qinghai (3.0%) (P<0.05). The presence of homA and sabA genes may be negatively correlated with the development of gastritis. There was no significant association between the frpB-4, hofC, homB gene and clinical outcomes. Conclusion The prevalence of homA, homB, and sabA genes and the sabA “on” or “off” status have significant geographical differences among five provinces in China. The presence of homA and sabA genes may be protective factors of gastritis.
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Affiliation(s)
- Mengyang Fang
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Zhijing Xue
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Lihua He
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yuanhai You
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yanan Gong
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Dongjie Fan
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Lu Sun
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Kangle Zhai
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yaming Yang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Jianzhong Zhang
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
- * E-mail:
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33
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Prasad NK, Seiple IB, Cirz RT, Rosenberg OS. Leaks in the Pipeline: a Failure Analysis of Gram-Negative Antibiotic Development from 2010 to 2020. Antimicrob Agents Chemother 2022; 66:e0005422. [PMID: 35471042 PMCID: PMC9112940 DOI: 10.1128/aac.00054-22] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The World Health Organization (WHO) has warned that our current arsenal of antibiotics is not innovative enough to face impending infectious diseases, especially those caused by multidrug-resistant Gram-negative pathogens. Although the current preclinical pipeline is well stocked with novel candidates, the last U.S. Food and Drug Administration (FDA)-approved antibiotic with a novel mechanism of action against Gram-negative bacteria was discovered nearly 60 years ago. Of all the antibiotic candidates that initiated investigational new drug (IND) applications in the 2000s, 17% earned FDA approval within 12 years, while an overwhelming 62% were discontinued in that time frame. These "leaks" in the clinical pipeline, where compounds with clinical potential are abandoned during clinical development, indicate that scientific innovations are not reaching the clinic and providing benefits to patients. This is true for not only novel candidates but also candidates from existing antibiotic classes with clinically validated targets. By identifying the sources of the leaks in the clinical pipeline, future developmental efforts can be directed toward strategies that are more likely to flow into clinical use. In this review, we conduct a detailed failure analysis of clinical candidates with Gram-negative activity that have fallen out of the clinical pipeline over the past decade. Although limited by incomplete data disclosure from companies engaging in antibiotic development, we attempt to distill the developmental challenges faced by each discontinued candidate. It is our hope that this insight can help de-risk antibiotic development and bring new, effective antibiotics to the clinic.
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Affiliation(s)
- Neha K. Prasad
- Chan Zuckerberg Biohub, San Francisco, California, USA
- Department of Medicine, University of California, San Francisco, San Francisco, California, USA
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, USA
| | - Ian B. Seiple
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, USA
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, USA
| | | | - Oren S. Rosenberg
- Chan Zuckerberg Biohub, San Francisco, California, USA
- Department of Medicine, University of California, San Francisco, San Francisco, California, USA
- Department of Biochemistry, University of California, San Francisco, San Francisco, California, USA
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34
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Cryo-EM structures of a LptDE transporter in complex with Pro-macrobodies offer insight into lipopolysaccharide translocation. Nat Commun 2022; 13:1826. [PMID: 35383177 PMCID: PMC8983717 DOI: 10.1038/s41467-022-29459-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Lipopolysaccharides are major constituents of the extracellular leaflet in the bacterial outer membrane and form an effective physical barrier for environmental threats and for antibiotics in Gram-negative bacteria. The last step of LPS insertion via the Lpt pathway is mediated by the LptD/E protein complex. Detailed insights into the architecture of LptDE transporter complexes have been derived from X-ray crystallography. However, no structure of a laterally open LptD transporter, a transient state that occurs during LPS release, is available to date. Here, we report a cryo-EM structure of a partially opened LptDE transporter in complex with rigid chaperones derived from nanobodies, at 3.4 Å resolution. In addition, a subset of particles allows to model a structure of a laterally fully opened LptDE complex. Our work offers insights into the mechanism of LPS insertion, provides a structural framework for the development of antibiotics targeting LptD and describes a highly rigid chaperone scaffold to enable structural biology of challenging protein targets. Lateral opening of the LptDE transporter in the outer membrane of Gram-negative bacteria is necessary for insertion of lipopolysaccharides. Here, Botte et al. report a cryo-EM structure of a partially opened LptDE transporter, in complex with rigid chaperones derived from nanobodies.
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35
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Sun J, Rutherford ST, Silhavy TJ, Huang KC. Physical properties of the bacterial outer membrane. Nat Rev Microbiol 2022; 20:236-248. [PMID: 34732874 PMCID: PMC8934262 DOI: 10.1038/s41579-021-00638-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2021] [Indexed: 11/09/2022]
Abstract
It has long been appreciated that the Gram-negative outer membrane acts as a permeability barrier, but recent studies have uncovered a more expansive and versatile role for the outer membrane in cellular physiology and viability. Owing to recent developments in microfluidics and microscopy, the structural, rheological and mechanical properties of the outer membrane are becoming apparent across multiple scales. In this Review, we discuss experimental and computational studies that have revealed key molecular factors and interactions that give rise to the spatial organization, limited diffusivity and stress-bearing capacity of the outer membrane. These physical properties suggest broad connections between cellular structure and physiology, and we explore future prospects for further elucidation of the implications of outer membrane construction for cellular fitness and survival.
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Affiliation(s)
- Jiawei Sun
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Steven T. Rutherford
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA 94080, USA,To whom correspondence should be addressed: , ,
| | - Thomas J. Silhavy
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA,To whom correspondence should be addressed: , ,
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA, USA. .,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA. .,Chan Zuckerberg Biohub, San Francisco, CA, USA.
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36
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Martorana AM, Moura ECCM, Sperandeo P, Di Vincenzo F, Liang X, Toone E, Zhou P, Polissi A. Degradation of Components of the Lpt Transenvelope Machinery Reveals LPS-Dependent Lpt Complex Stability in Escherichia coli. Front Mol Biosci 2022; 8:758228. [PMID: 35004843 PMCID: PMC8727689 DOI: 10.3389/fmolb.2021.758228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 11/23/2021] [Indexed: 11/13/2022] Open
Abstract
Lipopolysaccharide (LPS) is a peculiar component of the outer membrane (OM) of many Gram-negative bacteria that renders these bacteria highly impermeable to many toxic molecules, including antibiotics. LPS is assembled at the OM by a dedicated intermembrane transport system, the Lpt (LPS transport) machinery, composed of seven essential proteins located in the inner membrane (IM) (LptB2CFG), periplasm (LptA), and OM (LptDE). Defects in LPS transport compromise LPS insertion and assembly at the OM and result in an overall modification of the cell envelope and its permeability barrier properties. LptA is a key component of the Lpt machine. It connects the IM and OM sub-complexes by interacting with the IM protein LptC and the OM protein LptD, thus enabling the LPS transport across the periplasm. Defects in Lpt system assembly result in LptA degradation whose stability can be considered a marker of an improperly assembled Lpt system. Indeed, LptA recruitment by its IM and OM docking sites requires correct maturation of the LptB2CFG and LptDE sub-complexes, respectively. These quality control checkpoints are crucial to avoid LPS mistargeting. To further dissect the requirements for the complete Lpt transenvelope bridge assembly, we explored the importance of LPS presence by blocking its synthesis using an inhibitor compound. Here, we found that the interruption of LPS synthesis results in the degradation of both LptA and LptD, suggesting that, in the absence of the LPS substrate, the stability of the Lpt complex is compromised. Under these conditions, DegP, a major chaperone–protease in Escherichia coli, is responsible for LptD but not LptA degradation. Importantly, LptD and LptA stability is not affected by stressors disturbing the integrity of LPS or peptidoglycan layers, further supporting the notion that the LPS substrate is fundamental to keeping the Lpt transenvelope complex assembled and that LptA and LptD play a major role in the stability of the Lpt system.
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Affiliation(s)
- Alessandra M Martorana
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università Degli Studi di Milano, Milan, Italy
| | - Elisabete C C M Moura
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università Degli Studi di Milano, Milan, Italy
| | - Paola Sperandeo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università Degli Studi di Milano, Milan, Italy
| | - Flavia Di Vincenzo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università Degli Studi di Milano, Milan, Italy
| | - Xiaofei Liang
- Department of Chemistry, Duke University, Durham, NC, United States
| | - Eric Toone
- Department of Chemistry, Duke University, Durham, NC, United States
| | - Pei Zhou
- Department of Chemistry, Duke University, Durham, NC, United States.,Department of Biochemistry, Duke University School of Medicine, Durham, NC, United States
| | - Alessandra Polissi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università Degli Studi di Milano, Milan, Italy
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37
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Vieni C, Coudray N, Isom GL, Bhabha G, Ekiert DC. Role of Ring6 in the function of the E. coli MCE protein LetB. J Mol Biol 2022; 434:167463. [PMID: 35077766 PMCID: PMC9112829 DOI: 10.1016/j.jmb.2022.167463] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/15/2022] [Accepted: 01/18/2022] [Indexed: 10/19/2022]
Abstract
LetB is a tunnel-forming protein found in the cell envelope of some double-membraned bacteria, and is thought to be important for the transport of lipids between the inner and outer membranes. In Escherichia coli the LetB tunnel is formed from a stack of seven rings (Ring1 - Ring7), in which each ring is composed of a homo-hexameric assembly of MCE domains. The primary sequence of each MCE domain of the LetB protein is substantially divergent from the others, making each MCE ring unique in nature. The role of each MCE domain and how it contributes to the function of LetB is not well understood. Here we probed the importance of each MCE ring for the function of LetB, using a combination of bacterial growth assays and cryo-EM. Surprisingly, we find that ΔRing3 and ΔRing6 mutants, in which Ring3 and Ring6 have been deleted, confer increased resistance to membrane perturbing agents. Specific mutations in the pore-lining loops of Ring6 similarly confer increased resistance. A cryo-EM structure of the ΔRing6 mutant shows that despite the absence of Ring6, which leads to a shorter assembly, the overall architecture is maintained, highlighting the modular nature of MCE proteins. Previous work has shown that Ring6 is dynamic and in its closed state, may restrict the passage of substrate through the tunnel. Our work suggests that removal of Ring6 may relieve this restriction. The deletion of Ring6 combined with mutations in the pore-lining loops leads to a model for the tunnel gating mechanism of LetB. Together, these results provide insight into the functional roles of individual MCE domains and pore-lining loops in the LetB protein.
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38
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Tamrakar A, Singh R, Kumar A, Makde RD, Ashish, Kodgire P. Biophysical characterization of the homodimers of HomA and HomB, outer membrane proteins of Helicobacter pylori. Sci Rep 2021; 11:24471. [PMID: 34963695 PMCID: PMC8714817 DOI: 10.1038/s41598-021-04039-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 11/24/2021] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori is a Gram-negative bacterium that causes chronic inflammations in the stomach area and is involved in ulcers, which can develop into gastric malignancies. H. pylori attaches and colonizes to the human epithelium using some of their outer membrane proteins (OMPs). HomB and HomA are the most studied OMPs from H. pylori as they play a crucial role in adherence, hyper biofilm formation, antibiotic resistance and are also associated with severe gastric malignancies. The role of HomA and HomB in pathogenesis concerning their structure and function has not been evaluated yet. In the present study, we explored the structural aspect of HomA and HomB proteins using various computational, biophysical and small-angle X-ray scattering (SAXS) techniques. Interestingly, the in-silico analysis revealed that HomA/B consists of 8 discontinuous N and C terminal β-strands forming a small β-barrel, along with a large surface-exposed globular domain. Further, biophysical experiments suggested that HomA and HomB are dimeric and most likely the cysteine residues present on surface-exposed loops participate in protein-protein interactions. Our study provides essential structural information of unexplored proteins of the Hom family that can help in a better understanding of H. pylori pathogenesis.
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Affiliation(s)
- Anubhav Tamrakar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, 453 552, India
| | - Rahul Singh
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai, India
| | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, 453 552, India
| | - Ravindra D Makde
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai, India
| | - Ashish
- Protein Science and Engineering Division, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Prashant Kodgire
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, 453 552, India.
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39
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Egea PF. Mechanisms of Non-Vesicular Exchange of Lipids at Membrane Contact Sites: Of Shuttles, Tunnels and, Funnels. Front Cell Dev Biol 2021; 9:784367. [PMID: 34912813 PMCID: PMC8667587 DOI: 10.3389/fcell.2021.784367] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 11/08/2021] [Indexed: 11/13/2022] Open
Abstract
Eukaryotic cells are characterized by their exquisite compartmentalization resulting from a cornucopia of membrane-bound organelles. Each of these compartments hosts a flurry of biochemical reactions and supports biological functions such as genome storage, membrane protein and lipid biosynthesis/degradation and ATP synthesis, all essential to cellular life. Acting as hubs for the transfer of matter and signals between organelles and throughout the cell, membrane contacts sites (MCSs), sites of close apposition between membranes from different organelles, are essential to cellular homeostasis. One of the now well-acknowledged function of MCSs involves the non-vesicular trafficking of lipids; its characterization answered one long-standing question of eukaryotic cell biology revealing how some organelles receive and distribute their membrane lipids in absence of vesicular trafficking. The endoplasmic reticulum (ER) in synergy with the mitochondria, stands as the nexus for the biosynthesis and distribution of phospholipids (PLs) throughout the cell by contacting nearly all other organelle types. MCSs create and maintain lipid fluxes and gradients essential to the functional asymmetry and polarity of biological membranes throughout the cell. Membrane apposition is mediated by proteinaceous tethers some of which function as lipid transfer proteins (LTPs). We summarize here the current state of mechanistic knowledge of some of the major classes of LTPs and tethers based on the available atomic to near-atomic resolution structures of several "model" MCSs from yeast but also in Metazoans; we describe different models of lipid transfer at MCSs and analyze the determinants of their specificity and directionality. Each of these systems illustrate fundamental principles and mechanisms for the non-vesicular exchange of lipids between eukaryotic membrane-bound organelles essential to a wide range of cellular processes such as at PL biosynthesis and distribution, lipid storage, autophagy and organelle biogenesis.
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Affiliation(s)
- Pascal F Egea
- Department of Biological Chemistry, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States
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40
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Thoma J, Burmann BM. Architects of their own environment: How membrane proteins shape the Gram-negative cell envelope. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:1-34. [PMID: 35034716 DOI: 10.1016/bs.apcsb.2021.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Gram-negative bacteria are surrounded by a complex multilayered cell envelope, consisting of an inner and an outer membrane, and separated by the aqueous periplasm, which contains a thin peptidoglycan cell wall. These bacteria employ an arsenal of highly specialized membrane protein machineries to ensure the correct assembly and maintenance of the membranes forming the cell envelope. Here, we review the diverse protein systems, which perform these functions in Escherichia coli, such as the folding and insertion of membrane proteins, the transport of lipoproteins and lipopolysaccharide within the cell envelope, the targeting of phospholipids, and the regulation of mistargeted envelope components. Some of these protein machineries have been known for a long time, yet still hold surprises. Others have only recently been described and some are still missing pieces or yet remain to be discovered.
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Affiliation(s)
- Johannes Thoma
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Göteborg, Sweden; Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden.
| | - Björn M Burmann
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Göteborg, Sweden; Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
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41
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Larson MR, Biddle K, Gorman A, Boutom S, Rosenshine I, Saper MA. Escherichia coli O127 group 4 capsule proteins assemble at the outer membrane. PLoS One 2021; 16:e0259900. [PMID: 34780538 PMCID: PMC8592465 DOI: 10.1371/journal.pone.0259900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 10/28/2021] [Indexed: 12/26/2022] Open
Abstract
Enteropathogenic Escherichia coli O127 is encapsulated by a protective layer of polysaccharide made of the same strain specific O-antigen as the serotype lipopolysaccharide. Seven genes encoding capsule export functions comprise the group 4 capsule (gfc) operon. Genes gfcE, etk and etp encode homologs of the group 1 capsule secretion system but the upstream gfcABCD genes encode unknown functions specific to group 4 capsule export. We have developed an expression system for the large-scale production of the outer membrane protein GfcD. Contrary to annotations, we find that GfcD is a non-acylated integral membrane protein. Circular dichroism spectroscopy, light-scattering data, and the HHomp server suggested that GfcD is a monomeric β-barrel with 26 β-strands and an internal globular domain. We identified a set of novel protein-protein interactions between GfcB, GfcC, and GfcD, both in vivo and in vitro, and quantified the binding properties with isothermal calorimetry and biolayer interferometry. GfcC and GfcB form a high-affinity heterodimer with a KD near 100 nM. This heterodimer binds to GfcD (KD = 28 μM) significantly better than either GfcB or GfcC alone. These gfc proteins may form a complex at the outer membrane for group 4 capsule secretion or for a yet unknown function.
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Affiliation(s)
- Matthew R. Larson
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Kassia Biddle
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Adam Gorman
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sarah Boutom
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, United States of America
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Ilan Rosenshine
- Dept of Microbiology and Molecular Genetics, Hebrew University Faculty of Medicine, Ein Kerem, Jerusalem, Israel
| | - Mark A. Saper
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, United States of America
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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42
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Fiorentino F, Rotili D, Mai A, Bolla JR, Robinson CV. Mass spectrometry enables the discovery of inhibitors of an LPS transport assembly via disruption of protein-protein interactions. Chem Commun (Camb) 2021; 57:10747-10750. [PMID: 34585198 PMCID: PMC7614387 DOI: 10.1039/d1cc04186j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We developed a native mass spectrometry-based approach to quantify the monomer-dimer equilibrium of the LPS transport protein LptH. We use this method to assess the potency and efficacy of an antimicrobial peptide and small molecule disruptors, obtaining new information on their structure-activity relationships. This approach led to the identification of quinoline-based hit compounds representing the basis for the development of novel LPS transport inhibitors.
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Affiliation(s)
- Francesco Fiorentino
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK. .,The Kavli Institute for Nanoscience Discovery, 3 South Parks Road, Oxford, OX1 3QU, UK
| | - Dante Rotili
- Department of Drug Chemistry & Technologies, Sapienza University of Rome, P. le A Moro 5, Rome 00185, Italy.
| | - Antonello Mai
- Department of Drug Chemistry & Technologies, Sapienza University of Rome, P. le A Moro 5, Rome 00185, Italy.
| | - Jani R Bolla
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK. .,The Kavli Institute for Nanoscience Discovery, 3 South Parks Road, Oxford, OX1 3QU, UK
| | - Carol V Robinson
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK.
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43
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Vickery ON, Stansfeld PJ. CG2AT2: an Enhanced Fragment-Based Approach for Serial Multi-scale Molecular Dynamics Simulations. J Chem Theory Comput 2021; 17:6472-6482. [PMID: 34492188 PMCID: PMC8515810 DOI: 10.1021/acs.jctc.1c00295] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
![]()
Coarse-grained molecular
dynamics provides a means for simulating
the assembly and interactions of macromolecular complexes at a reduced
level of representation, thereby allowing both longer timescale and
larger sized simulations. Here, we describe an enhanced fragment-based
protocol for converting macromolecular complexes from coarse-grained
to atomistic resolution, for further refinement and analysis. While
the focus is upon systems that comprise an integral membrane protein
embedded in a phospholipid bilayer, the technique is also suitable
for membrane-anchored and soluble protein/nucleotide complexes. Overall,
this provides a method for generating an accurate and well-equilibrated
atomic-level description of a macromolecular complex. The approach
is evaluated using a diverse test set of 11 system configurations
of varying size and complexity. Simulations are assessed in terms
of protein stereochemistry, conformational drift, lipid/protein interactions,
and lipid dynamics.
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Affiliation(s)
- Owen N Vickery
- School of Life Sciences & Department of Chemistry, University of Warwick, Gibbet Hill Campus, Coventry CV4 7AL, U.K
| | - Phillip J Stansfeld
- School of Life Sciences & Department of Chemistry, University of Warwick, Gibbet Hill Campus, Coventry CV4 7AL, U.K
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Abidi W, Torres-Sánchez L, Siroy A, Krasteva PV. Weaving of bacterial cellulose by the Bcs secretion systems. FEMS Microbiol Rev 2021; 46:6388354. [PMID: 34634120 PMCID: PMC8892547 DOI: 10.1093/femsre/fuab051] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 10/08/2021] [Indexed: 12/13/2022] Open
Abstract
Cellulose is the most abundant biological compound on Earth and while it is the predominant building constituent of plants, it is also a key extracellular matrix component in many diverse bacterial species. While bacterial cellulose was first described in the 19th century, it was not until this last decade that a string of structural works provided insights into how the cellulose synthase BcsA, assisted by its inner-membrane partner BcsB, senses c-di-GMP to simultaneously polymerize its substrate and extrude the nascent polysaccharide across the inner bacterial membrane. It is now established that bacterial cellulose can be produced by several distinct types of cellulose secretion systems and that in addition to BcsAB, they can feature multiple accessory subunits, often indispensable for polysaccharide production. Importantly, the last years mark significant progress in our understanding not only of cellulose polymerization per se but also of the bigger picture of bacterial signaling, secretion system assembly, biofilm formation and host tissue colonization, as well as of structural and functional parallels of this dominant biosynthetic process between the bacterial and eukaryotic domains of life. Here, we review current mechanistic knowledge on bacterial cellulose secretion with focus on the structure, assembly and cooperativity of Bcs secretion system components.
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Affiliation(s)
- Wiem Abidi
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.,École doctorale 'Innovation thérapeutique: du fundamental à l'appliqué' (ITFA), Université Paris-Saclay, 92296, Chatenay-Malabry, France
| | - Lucía Torres-Sánchez
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.,École doctorale 'Innovation thérapeutique: du fundamental à l'appliqué' (ITFA), Université Paris-Saclay, 92296, Chatenay-Malabry, France
| | - Axel Siroy
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France
| | - Petya Violinova Krasteva
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France
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45
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Santos-Martin C, Wang G, Subedi P, Hor L, Totsika M, Paxman JJ, Heras B. Structural bioinformatic analysis of DsbA proteins and their pathogenicity associated substrates. Comput Struct Biotechnol J 2021; 19:4725-4737. [PMID: 34504665 PMCID: PMC8405906 DOI: 10.1016/j.csbj.2021.08.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/12/2021] [Accepted: 08/12/2021] [Indexed: 01/02/2023] Open
Abstract
The disulfide bond (DSB) forming system and in particular DsbA, is a key bacterial oxidative folding catalyst. Due to its role in promoting the correct assembly of a wide range of virulence factors required at different stages of the infection process, DsbA is a master virulence rheostat, making it an attractive target for the development of new virulence blockers. Although DSB systems have been extensively studied across different bacterial species, to date, little is known about how DsbA oxidoreductases are able to recognize and interact with such a wide range of substrates. This review summarizes the current knowledge on the DsbA enzymes, with special attention on their interaction with the partner oxidase DsbB and substrates associated with bacterial virulence. The structurally and functionally diverse set of bacterial proteins that rely on DsbA-mediated disulfide bond formation are summarized. Local sequence and secondary structure elements of these substrates are analyzed to identify common elements recognized by DsbA enzymes. This not only provides information on protein folding systems in bacteria but also offers tools for identifying new DsbA substrates and informs current efforts aimed at developing DsbA targeted anti-microbials.
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Affiliation(s)
- Carlos Santos-Martin
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Geqing Wang
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Pramod Subedi
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Lilian Hor
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Makrina Totsika
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Jason John Paxman
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Begoña Heras
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
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46
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Miyazaki R, Watanabe T, Yoshitani K, Akiyama Y. Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways. eLife 2021; 10:70541. [PMID: 34463613 PMCID: PMC8423444 DOI: 10.7554/elife.70541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/26/2021] [Indexed: 01/06/2023] Open
Abstract
The outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier. Escherichia coli periplasmic Zn-metallopeptidase BepA contributes to the maintenance of OM integrity through its involvement in the biogenesis and degradation of LptD, a β-barrel protein component of the lipopolysaccharide translocon. BepA either promotes the maturation of LptD when it is on the normal assembly pathway (on-pathway) or degrades it when its assembly is compromised (off-pathway). BepA performs these functions probably on the β‐barrel assembly machinery (BAM) complex. However, how BepA recognizes and directs an immature LptD to different pathways remains unclear. Here, we explored the interactions among BepA, LptD, and the BAM complex. We found that the interaction of the BepA edge-strand located adjacent to the active site with LptD was crucial not only for proteolysis but also, unexpectedly, for assembly promotion of LptD. Site-directed crosslinking analyses indicated that the unstructured N-terminal half of the β-barrel-forming domain of an immature LptD contacts with the BepA edge-strand. Furthermore, the C-terminal region of the β-barrel-forming domain of the BepA-bound LptD intermediate interacted with a ‘seam’ strand of BamA, suggesting that BepA recognized LptD assembling on the BAM complex. Our findings provide important insights into the functional mechanism of BepA.
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Affiliation(s)
- Ryoji Miyazaki
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Tetsuro Watanabe
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Kohei Yoshitani
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Yoshinori Akiyama
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
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47
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Luo Q, Shi H, Xu X. Cryo-EM structures of LptB 2FG and LptB 2FGC from Klebsiella pneumoniae in complex with lipopolysaccharide. Biochem Biophys Res Commun 2021; 571:20-25. [PMID: 34303191 DOI: 10.1016/j.bbrc.2021.07.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 01/28/2023]
Abstract
Lipopolysaccharide (LPS) is an essential component of the outer membrane (OM) in most Gram-negative bacteria. LPS transport from the inner membrane (IM) to the OM is achieved by seven lipopolysaccharide transport proteins (LptA-G). LptB2FG, an type VI ATP-binding cassette (ABC) transporter, forms a stable complex with LptC, extracts LPS from the IM and powers LPS transport to the OM. Here we report the cryo-EM structures of LptB2FG and LptB2FGC from Klebsiella pneumoniae in complex with LPS. The KpLptB2FG-LPS structure provides detailed interactions between LPS and the transporter, while the KpLptB2FGC-LPS structure may represent an intermediate state that the transmembrane helix of LptC has not been fully inserted into the transmembrane domains of LptB2FG.
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Affiliation(s)
- Qingshan Luo
- Department of Clinical Laboratory, Shenzhen Baoan Women's and Children's Hospital, Jinan University, Shenzhen, 518133, China; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Huigang Shi
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Xueqing Xu
- Department of Clinical Laboratory, Shenzhen Baoan Women's and Children's Hospital, Jinan University, Shenzhen, 518133, China.
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48
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Bahr G, González LJ, Vila AJ. Metallo-β-lactamases in the Age of Multidrug Resistance: From Structure and Mechanism to Evolution, Dissemination, and Inhibitor Design. Chem Rev 2021; 121:7957-8094. [PMID: 34129337 PMCID: PMC9062786 DOI: 10.1021/acs.chemrev.1c00138] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Antimicrobial resistance is one of the major problems in current practical medicine. The spread of genes coding for resistance determinants among bacteria challenges the use of approved antibiotics, narrowing the options for treatment. Resistance to carbapenems, last resort antibiotics, is a major concern. Metallo-β-lactamases (MBLs) hydrolyze carbapenems, penicillins, and cephalosporins, becoming central to this problem. These enzymes diverge with respect to serine-β-lactamases by exhibiting a different fold, active site, and catalytic features. Elucidating their catalytic mechanism has been a big challenge in the field that has limited the development of useful inhibitors. This review covers exhaustively the details of the active-site chemistries, the diversity of MBL alleles, the catalytic mechanism against different substrates, and how this information has helped developing inhibitors. We also discuss here different aspects critical to understand the success of MBLs in conferring resistance: the molecular determinants of their dissemination, their cell physiology, from the biogenesis to the processing involved in the transit to the periplasm, and the uptake of the Zn(II) ions upon metal starvation conditions, such as those encountered during an infection. In this regard, the chemical, biochemical and microbiological aspects provide an integrative view of the current knowledge of MBLs.
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Affiliation(s)
- Guillermo Bahr
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
| | - Lisandro J. González
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
| | - Alejandro J. Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda S/N, 2000 Rosario, Argentina
- Area Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
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49
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Javadmanesh A, Mohammadi E, Mousavi Z, Azghandi M, Tanhaiean A. Antibacterial effects assessment on some livestock pathogens, thermal stability and proposing a probable reason for different levels of activity of thanatin. Sci Rep 2021; 11:10890. [PMID: 34035354 PMCID: PMC8149819 DOI: 10.1038/s41598-021-90313-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 05/06/2021] [Indexed: 02/04/2023] Open
Abstract
There is a continuing need to prevent the increasing use of common antibiotic and find the replacement to combat the drug/antibiotic resistant bacteria such as antimicrobial peptides (AMPs) such as thanatin peptide. In this study, recombinant thanatin peptide was expressed in the HEK293 cell line. Then the antimicrobial properties of this peptide on some poultry and farm animal's pathogen strains were assessed. The thermal-stability of thanatin was predicted in various temperatures through in silico analysis. Afterwards, according to Minimum Inhibitory Concentration (MIC) results, Escherichia coli and Pseudomonas aeruginosa were chosen to test the hypothesis of LptA/LptD-thanatin interaction, computationally. Relative amino acid sequences and crystallography structures were retrieved and missed tertiary structures were predicted. The interaction of thanatin with LptA and LptD of Escherichia coli and Pseudomonas aeruginosa were analyzed subsequently. The antibacterial activity of thanatin peptide was evaluated between 6.25 and 100 μg/mL using minimum inhibitory concentration. Also, the amounts of minimum bactericidal concentrations (MBC) were between 12.5 and 200 μg/mL. The bioinformatics analysis followed by the in vitro assessment, demonstrated that thanatin would be thermally stable in the body temperature of poultry and farm animals. Thanatin could penetrate to the outer membrane domain of LptD in Escherichia coli and it could block the transition path of this protein while the entrance of LptD in Pseudomonas aeruginosa was blocked for thanatin by extra residues in comparison with Escherichia coli LptD. In addition, the quality of interaction, with regard to the number and distance of interactions which leads to higher binding energy for thanatin and LptD of Escherichia coli was much better than Pseudomonas aeruginosa. But the site and quality of interaction for thanatin and LptA was almost the same for Escherichia coli and Pseudomonas aeruginosa. Accordingly, thanatin can prevent the assembly of LptA periplasmic bridge in both pathogens. The antibacterial and thermal stability of the thanatin peptide suggested that thanatin peptide might serve as a natural alternative instead of common antibiotics in the veterinary medicine. The outcome of this in silico study supports the MIC results. Therefore, a probable reason for different level of activity of thanatin against Escherichia coli and Pseudomonas aeruginosa might be the quality of LptA/LptD-thanatin interaction.
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Affiliation(s)
- Ali Javadmanesh
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran, 9177948974.
- Stem Cell Biology and Regenerative Medicine Research Group, Research Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran.
| | - Elyas Mohammadi
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran, 9177948974
- Faculty of Pharmacy and 3P Medicine Laboratory, International Research Agendas Programme, Medical University of Gdańsk, Gdańsk, Poland
| | - Zahra Mousavi
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran, 9177948974
| | - Marjan Azghandi
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran, 9177948974
| | - Abass Tanhaiean
- Department of Plant Breeding, Faculty of Agriculture, Shahrood University of Technology, Shahrood, Iran
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50
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Wang S, Xiang D, Tian F, Ni M. Lipopolysaccharide from biofilm-forming Pseudomonas aeruginosa PAO1 induces macrophage hyperinflammatory responses. J Med Microbiol 2021; 70. [PMID: 33909550 PMCID: PMC8289208 DOI: 10.1099/jmm.0.001352] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Introduction. Macrophages polarization is essential in infection control. Llipopolysaccharide (LPS) plays an essential role in host innate immune system-pathogen interaction. The LPS structure of Pseudomonas aeruginosa modifies in the adaptation of this pathogen to biofilm-related chronic infection.Gap statement. There have been several studies on LPS induced polarization of human and mouse macrophages with different results. And it was reported that the lipid A structure of the LPS derived from biofilm-forming Pseudomonas aeruginosa strain PAO1 was modified.Aim. This study aimed to investigate the effect and the involved pathway of LPS from biofilm-forming PAO1 on human and murine macrophage polarization.Methodology. LPS was isolated from biofilm-forming and planktonic PAO1 and quantified. Then the LPS was added to PMA-differentiated human macrophage THP-1 cells and Raw264.7 murine macrophage cells. The expression of iNOS, Arg-1, IL4, TNF-α, CCL3, and CCL22 was analysed in the different cell lines. The expression of TICAM-1 and MyD88 in human THP-1 macrophages was quantified by Western blot. PAO1 infected macrophages at different polarization states, and the intracellular bacterial growth in macrophages was evaluated.Results. LPS from biofilm-forming PAO1 induced more marked hyperinflammatory responses in THP-1 and Raw264.7 macrophages than LPS derived from planktonic PAO1, and these responses were related to the up-regulation of MyD88. Intracellular growth of PAO1 was significantly increased in THP-1 macrophages polarized by LPS from biofilm-forming PAO1, but decreased both in THP-1 and Raw264.7 macrophages polarized by LPS from planktonic PAO1.Conclusion. The presented in vitro study indicates that LPS derived from biofilm-forming PAO1 induces enhanced M1 polarization in human and murine macrophage cell lines than LPS from planktonic PAO1.
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Affiliation(s)
- Sufei Wang
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Dandan Xiang
- Department of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Fangbing Tian
- Department of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Ming Ni
- Department of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
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