1
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Farvardin A, Llorens E, Liu-Xu L, Sánchez-Giménez L, Wong A, Biosca EG, Pedra JM, Falomir E, Camañes G, Scalschi L, Vicedo B. Solanum lycopersicum heme-binding protein 2 as a potent antimicrobial weapon against plant pathogens. Sci Rep 2023; 13:20336. [PMID: 37990046 PMCID: PMC10663603 DOI: 10.1038/s41598-023-47236-z] [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: 07/28/2023] [Accepted: 11/10/2023] [Indexed: 11/23/2023] Open
Abstract
The rise in antibiotic-resistant bacteria caused by the excessive use of antibiotics has led to the urgent exploration of alternative antimicrobial solutions. Among these alternatives, antimicrobial proteins, and peptides (Apps) have garnered attention due to their wide-ranging antimicrobial effects. This study focuses on evaluating the antimicrobial properties of Solanum lycopersicum heme-binding protein 2 (SlHBP2), an apoplastic protein extracted from tomato plants treated with 1-Methyl tryptophan (1-MT), against Pseudomonas syringae pv. tomato DC3000 (Pst). Computational studies indicate that SlHBP2 is annotated as a SOUL heme-binding family protein. Remarkably, recombinant SlHBP2 demonstrated significant efficacy in inhibiting the growth of Pst within a concentration range of 3-25 μg/mL. Moreover, SlHBP2 exhibited potent antimicrobial effects against other microorganisms, including Xanthomonas vesicatoria (Xv), Clavibacter michiganensis subsp. michiganensis (Cmm), and Botrytis cinerea. To understand the mechanism of action employed by SlHBP2 against Pst, various techniques such as microscopy and fluorescence assays were employed. The results revealed that SlHBP2 disrupts the bacterial cell wall and causes leakage of intracellular contents. To summarize, the findings suggest that SlHBP2 has significant antimicrobial properties, making it a potential antimicrobial agent against a wide range of pathogens. Although further studies are warranted to explore the full potential of SlHBP2 and its suitability in various applications.
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Affiliation(s)
- Atefeh Farvardin
- Biochemistry and Biotechnology Group, Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I, 12071, Castellón de la Plana, Spain
| | - Eugenio Llorens
- Biochemistry and Biotechnology Group, Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I, 12071, Castellón de la Plana, Spain
| | - Luisa Liu-Xu
- Biochemistry and Biotechnology Group, Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I, 12071, Castellón de la Plana, Spain
| | - Lorena Sánchez-Giménez
- Biochemistry and Biotechnology Group, Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I, 12071, Castellón de la Plana, Spain
| | - Aloysius Wong
- College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou, 325060, Zhejiang, China
| | - Elena G Biosca
- Department of Microbiology and Ecology, Universitat de Valencia, E-46100, Valencia, Spain
| | - José M Pedra
- Central Service of Scientific Instrumentation, Universitat Jaume I, 12071, Castellón de la Plana, Spain
| | - Eva Falomir
- Department of Inorganic and Organic Chemistry, Universitat Jaume I, 12071, Castellón de la Plana, Spain
| | - Gemma Camañes
- Biochemistry and Biotechnology Group, Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I, 12071, Castellón de la Plana, Spain
| | - Loredana Scalschi
- Biochemistry and Biotechnology Group, Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I, 12071, Castellón de la Plana, Spain.
| | - Begonya Vicedo
- Biochemistry and Biotechnology Group, Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I, 12071, Castellón de la Plana, Spain
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2
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Liu D, Jiang L, Chen J, Chen Z, Yuan C, Lin D, Huang M. Monomer and Oligomer Transition of Zinc Phthalocyanine Is Key for Photobleaching in Photodynamic Therapy. Molecules 2023; 28:4639. [PMID: 37375194 PMCID: PMC10305241 DOI: 10.3390/molecules28124639] [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: 05/06/2023] [Revised: 05/25/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Photodynamic therapy (PDT) is recognized as a powerful method to inactivate cells. However, the photosensitizer (PS), a key component of PDT, has suffered from undesired photobleaching. Photobleaching reduces reactive oxygen species (ROS) yields, leading to the compromise of and even the loss of the photodynamic effect of the PS. Therefore, much effort has been devoted to minimizing photobleaching in order to ensure that there is no loss of photodynamic efficacy. Here, we report that a type of PS aggregate showed neither photobleaching nor photodynamic action. Upon direct contact with bacteria, the PS aggregate was found to fall apart into PS monomers and thus possessed photodynamic inactivation against bacteria. Interestingly, the disassembly of the bound PS aggregate in the presence of bacteria was intensified by illumination, generating more PS monomers and leading to an enhanced antibacterial photodynamic effect. This demonstrated that on a bacterial surface, the PS aggregate photo-inactivated bacteria via PS monomer during irradiation, where the photodynamic efficiency was retained without photobleaching. Further mechanistic studies showed that PS monomers disrupted bacterial membranes and affected the expression of genes related to cell wall synthesis, bacterial membrane integrity, and oxidative stress. The results obtained here are applicable to other types of PSs in PDT.
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Affiliation(s)
- Dafeng Liu
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
- College of Chemistry, Fuzhou University, Fuzhou 350002, China
| | - Longguang Jiang
- College of Chemistry, Fuzhou University, Fuzhou 350002, China
| | - Jincan Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Zhuo Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Cai Yuan
- College of Chemistry, Fuzhou University, Fuzhou 350002, China
| | - Donghai Lin
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Mingdong Huang
- College of Chemistry, Fuzhou University, Fuzhou 350002, China
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3
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Zou J, Peng B, Qu J, Zheng J. Are Bacterial Persisters Dormant Cells Only? Front Microbiol 2022; 12:708580. [PMID: 35185807 PMCID: PMC8847742 DOI: 10.3389/fmicb.2021.708580] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial persisters are a sub-population of phenotypic variants that tolerate high concentrations of antibiotics within the genetically homogeneous cells. They resume division upon the removal of drugs. Bacterial persistence is one of major causes of antibiotic treatment failure and recurrent infection. Cell dormancy, triggered by toxin/antitoxin pair, (p)ppGpp, SOS response and ATP levels, is known to be the mechanistic basis for persistence. However, recent studies have demonstrated that bacteria with active metabolism can maintain persistence by lowering intracellular antibiotic concentration via an efflux pump. Additionally, others and our work have showed that cell wall deficient bacteria (CWDB), including both L-form and spheroplasts that produced by β-lactam antibiotics, are associated with antibiotic persistence. They are not dormant cells as their cell walls have been completely damaged. In this review, we discuss the various types of persisters and highlight the contribution of non-walled bacteria on bacterial persistence.
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Affiliation(s)
- Jin Zou
- Department of Clinical Laboratory, The Third People's Hospital of Shenzhen, Southern University of Science and Technology, National Clinical Research Center for Infectious Diseases, Shenzhen, China.,Faculty of Health Sciences, University of Macau, Zhuhai, Macau SAR, China
| | - Bo Peng
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Jiuxin Qu
- Department of Clinical Laboratory, The Third People's Hospital of Shenzhen, Southern University of Science and Technology, National Clinical Research Center for Infectious Diseases, Shenzhen, China
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Zhuhai, Macau SAR, China.,Institute of Translational Medicine, University of Macau, Zhuhai, Macau SAR, China
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4
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Effect of membrane potential on entry of lactoferricin B-derived 6-residue antimicrobial peptide into single Escherichia coli cells and lipid vesicles. J Bacteriol 2021; 203:JB.00021-21. [PMID: 33558393 PMCID: PMC8092161 DOI: 10.1128/jb.00021-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The antimicrobial peptide (AMP) derived from lactoferricin B, LfcinB (4-9) (RRWQWR), and lissamine rhodamine B red-labeled peptide (Rh-LfcinB (4-9)) exhibit strong antimicrobial activities, and they can enter Escherichia coli cells without damaging the cell membranes. Thus, these peptides are cell-penetrating peptide (CPP) -type AMPs. In this study, to elucidate the effect of the membrane potential (Δφ) on the action of the CPP-type AMP, Rh-LfcinB (4-9), we investigated the interactions of Rh-LfcinB (4-9) with single E. coli cells and spheroplasts containing calcein in the cytosol using confocal laser scanning microscopy. At low peptide concentrations, Rh-LfcinB (4-9) entered the cytosol of single E. coli cells and spheroplasts without damaging the cell membranes, and the H+-ionophore carbonyl cyanide m-chlorophenyl-hydrazone (CCCP) suppressed its entry. The studies using the time-kill method indicate that these low concentrations of peptide exhibit antimicrobial activity but CCCP inhibits this activity. Next, we investigated the effect of Δφ on the interaction of Rh-LfcinB (4-9) with single giant unilamellar vesicles (GUVs) comprising E. coli polar lipid extracts and containing a fluorescent probe, Alexa Fluor 647 hydrazide. At low concentrations (0.2-0.5 μM), Rh-LfcinB (4-9) showed significant entry to the single GUV lumen without pore formation in the presence of Δφ. The fraction of entry of peptide increased with increasing negative membrane potential, indicating that the rate of peptide entry into the GUV lumen increased with increasing negative membrane potential. These results indicate that Δφ enhances the entry of Rh-LfcinB (4-9) into single E. coli cells, spheroplasts, and GUVs and its antimicrobial activity.IMPORTANCE: Bacterial cells have a membrane potential (Δφ), but the effect of Δφ on action of cell-penetrating peptide-type antimicrobial peptides (AMPs) is not clear. Here, we investigated the effect of Δφ on the action of fluorescent probe-labeled AMP derived from lactoferricin B, Rh-LfcinB (4-9). At low peptide concentrations, Rh-LfcinB (4-9) enters the cytosol of Escherichia coli cells and spheroplasts without damaging their cell membrane, but a protonophore suppresses this entry and its antimicrobial activity. The rate of entry of Rh-LfcinB (4-9) into the giant unilamellar vesicles (GUVs) comprising E. coli lipids without pore formation increases with increasing Δφ. These results indicate that Δφ enhances the antimicrobial activity of Rh-LfcinB (4-9) and hence LfcinB (4-9) by increasing the rate of their entry into the cytosol.
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5
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Portelinha J, Duay SS, Yu SI, Heilemann K, Libardo MDJ, Juliano SA, Klassen JL, Angeles-Boza AM. Antimicrobial Peptides and Copper(II) Ions: Novel Therapeutic Opportunities. Chem Rev 2021; 121:2648-2712. [PMID: 33524257 DOI: 10.1021/acs.chemrev.0c00921] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The emergence of new pathogens and multidrug resistant bacteria is an important public health issue that requires the development of novel classes of antibiotics. Antimicrobial peptides (AMPs) are a promising platform with great potential for the identification of new lead compounds that can combat the aforementioned pathogens due to their broad-spectrum antimicrobial activity and relatively low rate of resistance emergence. AMPs of multicellular organisms made their debut four decades ago thanks to ingenious researchers who asked simple questions about the resistance to bacterial infections of insects. Questions such as "Do fruit flies ever get sick?", combined with pioneering studies, have led to an understanding of AMPs as universal weapons of the immune system. This review focuses on a subclass of AMPs that feature a metal binding motif known as the amino terminal copper and nickel (ATCUN) motif. One of the metal-based strategies of hosts facing a pathogen, it includes wielding the inherent toxicity of copper and deliberately trafficking this metal ion into sites of infection. The sudden increase in the concentration of copper ions in the presence of ATCUN-containing AMPs (ATCUN-AMPs) likely results in a synergistic interaction. Herein, we examine common structural features in ATCUN-AMPs that exist across species, and we highlight unique features that deserve additional attention. We also present the current state of knowledge about the molecular mechanisms behind their antimicrobial activity and the methods available to study this promising class of AMPs.
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Affiliation(s)
- Jasmin Portelinha
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Searle S Duay
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States.,Chemistry Department, Adamson University, 900 San Marcelino Street, Ermita, Manila 1000, Philippines
| | - Seung I Yu
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Kara Heilemann
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - M Daben J Libardo
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Samuel A Juliano
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Jonathan L Klassen
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Alfredo M Angeles-Boza
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States.,Institute of Material Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
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6
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Antimicrobial Mechanism of pBD2 against Staphylococcus aureus. Molecules 2020; 25:molecules25153513. [PMID: 32752087 PMCID: PMC7435708 DOI: 10.3390/molecules25153513] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 12/17/2022] Open
Abstract
Antimicrobial peptides (AMPs) show high antibacterial activity against pathogens, which makes them potential new therapeutics to prevent and cure diseases. Porcine beta defensin 2 (pBD2) is a newly discovered AMP and has shown antibacterial activity against different bacterial species including multi-resistant bacteria. In this study, the functional mechanism of pBD2 antibacterial activity against Staphylococcus aureus was investigated. After S. aureus cells were incubated with different concentrations of pBD2, the morphological changes in S. aureus and locations of pBD2 were detected by electron microscopy. The differentially expressed genes (DEGs) were also analyzed. The results showed that the bacterial membranes were broken, bulging, and perforated after treatment with pBD2; pBD2 was mainly located on the membranes, and some entered the cytoplasm. Furthermore, 31 DEGs were detected and confirmed by quantitative real-time PCR (qRT-PCR). The known functional DEGs were associated with transmembrane transport, transport of inheritable information, and other metabolic processes. Our data suggest that pBD2 might have multiple modes of action, and the main mechanism by which pBD2 kills S. aureus is the destruction of the membrane and interaction with DNA. The results imply that pBD2 is an effective bactericide for S. aureus, and deserves further study as a new therapeutic substance against S. aureus.
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7
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Juliano SA, Serafim LF, Duay SS, Heredia Chavez M, Sharma G, Rooney M, Comert F, Pierce S, Radulescu A, Cotten ML, Mihailescu M, May ER, Greenwood AI, Prabhakar R, Angeles-Boza AM. A Potent Host Defense Peptide Triggers DNA Damage and Is Active against Multidrug-Resistant Gram-Negative Pathogens. ACS Infect Dis 2020; 6:1250-1263. [PMID: 32251582 DOI: 10.1021/acsinfecdis.0c00051] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Gram-negative bacteria are some of the biggest threats to public health due to a large prevalence of antibiotic resistance. The difficulty in treating bacterial infections, stemming from their double membrane structure combined with efflux pumps in the outer membrane, has resulted in a much greater need for antimicrobials with activity against these pathogens. Tunicate host defense peptide (HDP), Clavanin A, is capable of not only inhibiting Gram-negative growth but also potentiating activity in the presence of Zn(II). Here, we provide evidence that the improvements of Clavanin A activity in the presence of Zn(II) are due to its novel mechanism of action. We employed E. coli TD172 (ΔrecA::kan) and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay to show in cellulae that DNA damage occurs upon treatment with Clavanin A. In vitro assays demonstrated that Zn(II) ions are required for the nuclease activity of the peptide. The quantum mechanics/molecular mechanics (QM/MM) calculations were used to investigate the mechanism of DNA damage. In the rate-determining step of the proposed mechanism, due to its Lewis acidity, the Zn(II) ion activates the scissile P-O bond of DNA and creates a hydroxyl nucleophile from a water molecule. A subsequent attack by this group to the electrophilic phosphorus cleaves the scissile phosphoester bond. Additionally, we utilized bacterial cytological profiling (BCP), circular dichroism (CD) spectroscopy in the presence of lipid vesicles, and surface plasmon resonance combined with electrical impedance spectroscopy in order to address the apparent discrepancies between our results and the previous studies regarding the mechanism of action of Clavanin A. Finally, our approach may lead to the identification of additional Clavanin A like HDPs and promote the development of antimicrobial peptide based therapeutics.
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Affiliation(s)
- Samuel A. Juliano
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Leonardo F. Serafim
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | - Searle S. Duay
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Maria Heredia Chavez
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Gaurav Sharma
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | - Mary Rooney
- Department of Applied Science, William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Fatih Comert
- Institute for Bioscience and Biotechnology Research, University of Maryland, 9600 Gudelsky Drive, Rockville, Maryland 20850, United States
| | - Scott Pierce
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Andrei Radulescu
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Myriam L. Cotten
- Department of Applied Science, William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Mihaela Mihailescu
- Institute for Bioscience and Biotechnology Research, University of Maryland, 9600 Gudelsky Drive, Rockville, Maryland 20850, United States
| | - Eric R. May
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Alexander I. Greenwood
- Department of Applied Science, William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | - Alfredo M. Angeles-Boza
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
- Institute of Materials Science, University of Connecticut, 97 N. Eagleville Road, Storrs, Connecticut 06269, United States
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8
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Moghal MMR, Hossain F, Yamazaki M. Action of antimicrobial peptides and cell-penetrating peptides on membrane potential revealed by the single GUV method. Biophys Rev 2020; 12:339-348. [PMID: 32152921 PMCID: PMC7242587 DOI: 10.1007/s12551-020-00662-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 02/23/2020] [Indexed: 02/06/2023] Open
Abstract
Membrane potential plays various key roles in live bacterial and eukaryotic cells. So far, the effects of membrane potential on action of antimicrobial peptides (AMPs) and cell-penetrating peptides (CPPs) have been examined using cells and small lipid vesicles. However, due to the technical drawbacks of these experiments, the effect of membrane potential on the actions of AMPs and CPPs and the elementary processes of interactions of these peptides with cell membranes and vesicle membranes are not well understood. In this short review, we summarize the results of the effect of membrane potential on the action of an AMP, lactoferricin B (LfcinB), and a CPP, transportan 10 (TP10), in vesicle membranes revealed by the single giant unilamellar vesicle (GUV) method. Parts of the actions and their elementary steps of AMPs and CPPs interacting vesicle membranes under membrane potential are clearly revealed using the single GUV method. The experimental methods and their analysis described here can be used to elucidate the effects of membrane potential on various activities of peptides such as AMPs, CPPs, and proteins. Moreover, GUVs with membrane potential are more suitable as a model of cells or artificial cells, as well as GUVs containing small vesicles.
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Affiliation(s)
- Md Mizanur Rahman Moghal
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan
- Department of Pharmacy, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
| | - Farzana Hossain
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Masahito Yamazaki
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan.
- Nanomaterials Research Division, Research Institute of Electronics, Shizuoka University, 836 Oya, Suruga-ku, Shizuoka, 422-8529, Japan.
- Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529, Japan.
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9
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Buck AK, Elmore DE, Darling LEO. Using fluorescence microscopy to shed light on the mechanisms of antimicrobial peptides. Future Med Chem 2019; 11:2445-2458. [PMID: 31517514 PMCID: PMC6787493 DOI: 10.4155/fmc-2019-0095] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/18/2019] [Indexed: 12/18/2022] Open
Abstract
Antimicrobial peptides (AMPs) are promising in the fight against increasing bacterial resistance, but the development of AMPs with enhanced activity requires a thorough understanding of their mechanisms of action. Fluorescence microscopy is one of the most flexible and effective tools to characterize AMPs, particularly in its ability to measure the membrane interactions and cellular localization of peptides. Recent advances have increased the scope of research questions that can be addressed via microscopy through improving spatial and temporal resolution. Unique combinations of fluorescent labels and dyes can simultaneously consider different aspects of peptide-membrane interaction mechanisms. This review emphasizes the central role that fluorescence microscopy will continue to play in the interrogation of AMP structure-function relationships and the engineering of more potent peptides.
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Affiliation(s)
- Anne K Buck
- Biochemistry Program, Wellesley College, Wellesley, MA 02481, USA
| | - Donald E Elmore
- Department of Chemistry & Biochemistry Program, Wellesley College, Wellesley, MA 02481, USA
| | - Louise EO Darling
- Department of Biological Sciences & Biochemistry Program, Wellesley College, Wellesley, MA 02481, USA
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10
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Hossain F, Moghal MMR, Islam MZ, Moniruzzaman M, Yamazaki M. Membrane potential is vital for rapid permeabilization of plasma membranes and lipid bilayers by the antimicrobial peptide lactoferricin B. J Biol Chem 2019; 294:10449-10462. [PMID: 31118274 DOI: 10.1074/jbc.ra119.007762] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/17/2019] [Indexed: 11/06/2022] Open
Abstract
Lactoferricin B (LfcinB) is a cationic antimicrobial peptide, and its capacity to damage the bacterial plasma membrane is suggested to be a main factor in LfcinB's antimicrobial activity. However, the specific processes and mechanisms in LfcinB-induced membrane damage are unclear. In this report, using confocal laser-scanning microscopy, we examined the interaction of LfcinB with single Escherichia coli cells and spheroplasts containing the water-soluble fluorescent probe calcein in the cytoplasm. LfcinB induced rapid calcein leakage from single E. coli cells and from single spheroplasts, indicating that LfcinB interacts directly with the plasma membrane and induces its rapid permeabilization. The proton ionophore carbonyl cyanide m-chlorophenylhydrazone suppressed this leakage. Next, we used the single giant unilamellar vesicle (GUV) method to examine LfcinB's interaction with GUVs comprising polar lipid extracts of E. coli containing a water-soluble fluorescent probe, Alexa Fluor 647 hydrazide (AF647). We observed that LfcinB stochastically induces local rupture in single GUVs, causing rapid AF647 leakage; however, higher LfcinB concentrations were required for AF647 leakage from GUVs than from E. coli cells and spheroplasts. To identify the reason for this difference, we examined the effect of membrane potential on LfcinB-induced pore formation, finding that the rate of LfcinB-induced local rupture in GUVs increases greatly with increasing negative membrane potential. These results indicate that membrane potential plays an important role in LfcinB-induced local rupture of lipid bilayers and rapid permeabilization of E. coli plasma membranes. On the basis of these results, we discuss the mode of action of LfcinB's antimicrobial activity.
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Affiliation(s)
- Farzana Hossain
- From the Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529
| | - Md Mizanur Rahman Moghal
- From the Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529
| | - Md Zahidul Islam
- From the Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529
| | - Md Moniruzzaman
- From the Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529
| | - Masahito Yamazaki
- From the Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, .,the Nanomaterials Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka 422-8529, and.,the Department of Physics, Graduate School of Science, Shizuoka University, Shizuoka 422-8529, Japan
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11
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Wade HM, Darling LEO, Elmore DE. Hybrids made from antimicrobial peptides with different mechanisms of action show enhanced membrane permeabilization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:182980. [PMID: 31067436 DOI: 10.1016/j.bbamem.2019.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 04/25/2019] [Accepted: 05/01/2019] [Indexed: 01/30/2023]
Abstract
Combining two known antimicrobial peptides (AMPs) into a hybrid peptide is one promising avenue in the design of agents with increased antibacterial activity. However, very few previous studies have considered the effect of creating a hybrid from one AMP that permeabilizes membranes and another AMP that acts intracellularly after translocating across the membrane. Moreover, very few studies have systematically evaluated the order of parent peptides or the presence of linkers in the design of hybrid AMPs. Here, we use a combination of antibacterial measurements, cellular assays and semi-quantitative confocal microscopy to characterize the activity and mechanism for a library of sixteen hybrid peptides. These hybrids consist of permutations of two primarily membrane translocating peptides, buforin II and DesHDAP1, and two primarily membrane permeabilizing peptides, magainin 2 and parasin. For all hybrids, the permeabilizing peptide appeared to dominate the mechanism, with hybrids primarily killing bacteria through membrane permeabilization. We also observed increased hybrid activity when the permeabilizing parent peptide was placed at the N-terminus. Activity data also highlighted the potential value of considering AMP cocktails in addition to hybrid peptides. Together, these observations will guide future design efforts aiming to design more active hybrid AMPs.
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Affiliation(s)
- Heidi M Wade
- Department of Chemistry, Wellesley College, Wellesley, MA 02481, United States of America; Biochemistry Program, Wellesley College, Wellesley, MA 02481, United States of America
| | - Louise E O Darling
- Biochemistry Program, Wellesley College, Wellesley, MA 02481, United States of America; Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, United States of America
| | - Donald E Elmore
- Department of Chemistry, Wellesley College, Wellesley, MA 02481, United States of America; Biochemistry Program, Wellesley College, Wellesley, MA 02481, United States of America.
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12
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Chen RB, Zhang K, Zhang H, Gao CY, Li CL. Analysis of the antimicrobial mechanism of porcine beta defensin 2 against E. coli by electron microscopy and differentially expressed genes. Sci Rep 2018; 8:14711. [PMID: 30279556 PMCID: PMC6168601 DOI: 10.1038/s41598-018-32822-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 09/13/2018] [Indexed: 12/15/2022] Open
Abstract
Porcine beta defensin 2 (pBD2) is a cationic antimicrobial peptide with broad spectrum antibacterial activity, which makes it a potential alternative to antibiotics to prevent and cure diseases of pigs. However, development of pBD2 as an effective antibiotic agent requires molecular understanding of its functional mechanism against pathogens. In this study, we investigated the functional mechanism of pBD2 antibacterial activity. Escherichia coli was incubated with different pBD2 concentrations for different times. Electron microscopy was used to analyze the locations of pBD2 and its induced morphological changes in E. coli. Gene expression analysis was also performed to further understand the molecular changes of E. coli in response to pBD2 incubation. The results demonstrated that E. coli membranes were broken, holed, and wrinkled after treatment with pBD2, and pBD2 was located on the cell membranes and manly in the cytoplasm. Furthermore, 38 differentially expressed genes (DEGs) were detected, successfully sequenced and confirmed by quantitative real-time PCR (qRT-PCR). Most of the known functional DEGs were associated with DNA transcription and translation and located in the cytoplasm. Collectively, the results suggest that pBD2 could have multiple modes of action and the main mechanism for killing E. coli might be influence on DNA transcription and translation by targeting intracellular molecules after membrane damage, although transport and metabolism proteins were also affected.
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Affiliation(s)
- Rui-Bo Chen
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China
| | - Kun Zhang
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China
| | - Heng Zhang
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China
| | - Chun-Yu Gao
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China
| | - Chun-Li Li
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China.
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13
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Figueroa DM, Wade HM, Montales KP, Elmore DE, Darling LEO. Production and Visualization of Bacterial Spheroplasts and Protoplasts to Characterize Antimicrobial Peptide Localization. J Vis Exp 2018:57904. [PMID: 30148492 PMCID: PMC6126710 DOI: 10.3791/57904] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The use of confocal microscopy as a method to assess peptide localization patterns within bacteria is commonly inhibited by the resolution limits of conventional light microscopes. As the resolution for a given microscope cannot be easily enhanced, we present protocols to transform the small rod-shaped gram-negative Escherichia coli (E. coli) and gram-positive Bacillus megaterium (B. megaterium) into larger, easily imaged spherical forms called spheroplasts or protoplasts. This transformation allows observers to rapidly and clearly determine whether peptides lodge themselves into the bacterial membrane (i.e., membrane localizing) or cross the membrane to enter the cell (i.e., translocating). With this approach, we also present a systematic method to characterize peptides as membrane localizing or translocating. While this method can be used for a variety of membrane-active peptides and bacterial strains, we demonstrate the utility of this protocol by observing the interaction of Buforin II P11A (BF2 P11A), an antimicrobial peptide (AMP), with E. coli spheroplasts and B. megaterium protoplasts.
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Affiliation(s)
| | - Heidi M Wade
- Biochemistry Program, Wellesley College; Department of Chemistry, Wellesley College
| | | | - Donald E Elmore
- Biochemistry Program, Wellesley College; Department of Chemistry, Wellesley College;
| | - Louise E O Darling
- Biochemistry Program, Wellesley College; Department of Biological Sciences, Wellesley College;
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14
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Sim S, Wang P, Beyer BN, Cutrona KJ, Radhakrishnan ML, Elmore DE. Investigating the nucleic acid interactions of histone-derived antimicrobial peptides. FEBS Lett 2017; 591:706-717. [PMID: 28130840 DOI: 10.1002/1873-3468.12574] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/13/2017] [Accepted: 01/22/2017] [Indexed: 11/05/2022]
Abstract
While many antimicrobial peptides (AMPs) disrupt bacterial membranes, some translocate into bacteria and interfere with intracellular processes. Buforin II and DesHDAP1 are thought to kill bacteria by interacting with nucleic acids. Here, molecular modeling and experimental measurements are used to show that neither nucleic acid binding peptide selectively binds DNA sequences. Simulations and experiments also show that changing lysines to arginines enhances DNA binding, suggesting that including additional guanidinium groups is a potential strategy to engineer more potent AMPs. Moreover, the lack of binding specificity may make it more difficult for bacteria to evolve resistance to these and other similar AMPs.
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Affiliation(s)
- Sukin Sim
- Department of Chemistry, Wellesley College, MA, USA
| | - Penny Wang
- Department of Chemistry, Wellesley College, MA, USA
| | | | | | - Mala L Radhakrishnan
- Department of Chemistry, Wellesley College, MA, USA.,Biochemistry Program, Wellesley College, MA, USA
| | - Donald E Elmore
- Department of Chemistry, Wellesley College, MA, USA.,Biochemistry Program, Wellesley College, MA, USA
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