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Kanagasingam S, von Ruhland C, Welbury R, Singhrao SK. Antimicrobial, Polarizing Light, and Paired Helical Filament Properties of Fragmented Tau Peptides of Selected Putative Gingipains. J Alzheimers Dis 2022; 89:1279-1291. [PMID: 36031895 DOI: 10.3233/jad-220486] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Tau is an established substrate for gingipains secreted by Porphyromonas gingivalis. Hyperphosphorylation of tau and neurofibrillary tangle (NFT) formation is a defining lesion of Alzheimer's disease (AD) where NFT distribution is related to Braak stage and disease severity. OBJECTIVE To assess gingipains'-fragmented tau peptides for their antimicrobial properties and for the likelihood of paired helical/straight filament (PHF/SF) formation with implications for the NFT lesion. METHODS Seven non-phosphorylated (A-G) and three phosphorylated (A-C) tau peptides, were tested for antimicrobial properties against P. gingivalis. Polarizing light properties were determined using Congo Red staining. Secondary and tertiary structures of peptides B-F were determined using transmission electron microscopy (TEM) and circular dichroism (CD) was undertaken for the soluble peptides A in phosphorylated and non-phosphorylated states. RESULTS Phosphorylated tau peptide A displayed a significant effect against planktonic P. gingivalis. The CD results demonstrated that both peptides A, in phosphorylated and non-phosphorylated states, in aqueous solution, adopted mainly β-type structures. Non-phosphorylated peptides B-F and phosphorylated peptides B-C were insoluble and fibrillar under the TEM. The secondary and tertiary structures of the non-phosphorylated peptide B demonstrated fewer helical twists, whereas peptide C displayed significantly more helical twists along the whole fiber(s) length following its phosphorylation. CONCLUSION Phosphorylated peptide A reduced P. gingivalis viability. CD spectroscopy demonstrated the phosphorylated and the non-phosphorylated peptide A predominantly formed from β-sheet structures in aqueous solution with potential antimicrobial activity. Phosphorylation of tau peptides physically changed their tertiary structure into PHFs with potential for self-aggregation and binding to the NFT lesion.
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Affiliation(s)
- Shalini Kanagasingam
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Christopher von Ruhland
- Electron and Light Microscopy Facility, College of Biomedical and Life Sciences, Cardiff University, Wales, UK
| | - Richard Welbury
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Sim K Singhrao
- Brain and Behavior Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
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Zhang R, Fan X, Jiang X, Zou M, Xiao H, Wu G. Multiple Mechanisms of the Synthesized Antimicrobial Peptide TS against Gram-Negative Bacteria for High Efficacy Antibacterial Action In Vivo. Molecules 2020; 26:molecules26010060. [PMID: 33374458 PMCID: PMC7795306 DOI: 10.3390/molecules26010060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 12/02/2022] Open
Abstract
The emergence of drug-resistant bacteria emphasizes the urgent need for novel antibiotics. The antimicrobial peptide TS shows extensive antibacterial activity in vitro and in vivo, especially in gram-negative bacteria; however, its antibacterial mechanism is unclear. Here, we find that TS without hemolytic activity disrupts the integrity of the outer bacterial cell membrane by displacing divalent cations and competitively binding lipopolysaccharides. In addition, the antimicrobial peptide TS can inhibit and kill E. coli by disintegrating the bacteria from within by interacting with bacterial DNA. Thus, antimicrobial peptide TS’s multiple antibacterial mechanisms may not easily induce bacterial resistance, suggesting use as an antibacterial drug to be for combating bacterial infections in the future.
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Affiliation(s)
- Rui Zhang
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Xiaobo Fan
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Xinglu Jiang
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Mingyuan Zou
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Han Xiao
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Guoqiu Wu
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Southeast University, Nanjing 210009, China
- Department of Clinical Laboratory Medicine, Zhongda Hospital, Southeast University, Nanjing 210009, China
- Correspondence: ; Tel.: +86-25-83272503
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Cardon S, Sachon E, Carlier L, Drujon T, Walrant A, Alemán-Navarro E, Martínez-Osorio V, Guianvarc'h D, Sagan S, Fleury Y, Marquant R, Piesse C, Rosenstein Y, Auvynet C, Lacombe C. Peptidoglycan potentiates the membrane disrupting effect of the carboxyamidated form of DMS-DA6, a Gram-positive selective antimicrobial peptide isolated from Pachymedusa dacnicolor skin. PLoS One 2018; 13:e0205727. [PMID: 30325956 PMCID: PMC6191125 DOI: 10.1371/journal.pone.0205727] [Citation(s) in RCA: 6] [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: 05/29/2018] [Accepted: 10/01/2018] [Indexed: 11/18/2022] Open
Abstract
The occurrence of nosocomial infections has been on the rise for the past twenty years. Notably, infections caused by the Gram-positive bacteria Staphylococcus aureus represent a major clinical problem, as an increase in antibiotic multi-resistant strains has accompanied this rise. There is thus a crucial need to find and characterize new antibiotics against Gram-positive bacteria, and against antibiotic-resistant strains in general. We identified a new dermaseptin, DMS-DA6, produced by the skin of the Mexican frog Pachymedusa dacnicolor, with specific antibacterial activity against Gram-positive bacteria. This peptide is particularly effective against two multiple drug-resistant strains Enterococcus faecium BM4147 and Staphylococcus aureus DAR5829, and has no hemolytic activity. DMS-DA6 is naturally produced with the C-terminal carboxyl group in either the free or amide forms. By using Gram-positive model membranes and different experimental approaches, we showed that both forms of the peptide adopt an α-helical fold and have the same ability to insert into, and to disorganize a membrane composed of anionic lipids. However, the bactericidal capacity of DMS-DA6-NH2 was consistently more potent than that of DMS-DA6-OH. Remarkably, rather than resulting from the interaction with the negatively charged lipids of the membrane, or from a more stable conformation towards proteolysis, the increased capacity to permeabilize the membrane of Gram-positive bacteria of the carboxyamidated form of DMS-DA6 was found to result from its enhanced ability to interact with peptidoglycan.
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Affiliation(s)
- Sébastien Cardon
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
| | - Emmanuelle Sachon
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Plate-forme Spectrométrie de Masse et Protéomique, Paris, France
| | - Ludovic Carlier
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
| | - Thierry Drujon
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
| | - Astrid Walrant
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
| | - Estefanía Alemán-Navarro
- Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Verónica Martínez-Osorio
- Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Dominique Guianvarc'h
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
| | - Sandrine Sagan
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
| | - Yannick Fleury
- Université de Bretagne Occidentale, LUBEM EA, IUT Quimper, Quimper, France
| | - Rodrigue Marquant
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
| | - Christophe Piesse
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Plate-forme de Synthèse Peptidique, Paris, France
| | - Yvonne Rosenstein
- Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Constance Auvynet
- Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- * E-mail: (CA); (CL)
| | - Claire Lacombe
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, Paris, France
- Faculté des Sciences et Technologie, Université Paris Est-Créteil Val de Marne, Créteil, France
- * E-mail: (CA); (CL)
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Pei J, Feng Z, Ren T, Jin W, Li X, Chen D, Tao Y, Dang J. Selectively screen the antibacterial peptide from the hydrolysates of highland barley. Eng Life Sci 2017; 18:48-54. [PMID: 32624860 DOI: 10.1002/elsc.201700118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/17/2017] [Accepted: 09/25/2017] [Indexed: 12/20/2022] Open
Abstract
Highland barley is one of the most important industrial crops in Tibetan plateau. Previous research indicated that highland barley has many medical functions. In this work, the antibacterial abilities of highland barley were investigated. The protein solutions hydrolyzed by trypsin for 4 h exhibited the highest antibacterial activity. An antibacterial peptide, barleycin, was screened and purified by magnetic liposome extraction combining with the protein profiles of reversed-phase high-performance liquid chromatography (RP-HPLC). Structure, characterization, and safety evaluation of barleycin were further investigated. Amino acids sequence was determined as Lys-Ile-Ile-Ile-Pro-Pro-Leu-Phe-His by N-sequencing. Circular dichroism spectra indicated the a-helix conformation of barleycin. The activity spectrum included Bacillus subtilis, Staphylcoccus aureus, Listeria innocua and Escherichia coli and the MICs were from 4 to 16 μg/mL. Safety evaluations with cytotoxicity and hemolytic suggested this antibacterial peptide could be considered as safe at MICs. Finally, mode of action of barleycin on sensitive cells was primarily studied. The results suggested the damage of cell membrane.
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Affiliation(s)
- Jinjin Pei
- Shaanxi Key Laboratory of Biology and Bioresources Shaanxi University of Technology Hanzhogn Shaanxi P. R. China.,Key laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology Chinese Academy of Sciences Xining P. R. China.,Qinghai Key Laboratory of Tibetan Medicine Research Xining P. R. China
| | - Zhenzhen Feng
- Shaanxi Key Laboratory of Biology and Bioresources Shaanxi University of Technology Hanzhogn Shaanxi P. R. China
| | - Ting Ren
- Shaanxi Key Laboratory of Biology and Bioresources Shaanxi University of Technology Hanzhogn Shaanxi P. R. China
| | - Wengang Jin
- Shaanxi Key Laboratory of Biology and Bioresources Shaanxi University of Technology Hanzhogn Shaanxi P. R. China
| | - Xinsheng Li
- Shaanxi Key Laboratory of Biology and Bioresources Shaanxi University of Technology Hanzhogn Shaanxi P. R. China
| | - Dejing Chen
- Shaanxi Key Laboratory of Biology and Bioresources Shaanxi University of Technology Hanzhogn Shaanxi P. R. China
| | - Yanduo Tao
- Key laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology Chinese Academy of Sciences Xining P. R. China.,Qinghai Key Laboratory of Tibetan Medicine Research Xining P. R. China
| | - Jun Dang
- Key laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology Chinese Academy of Sciences Xining P. R. China.,Qinghai Key Laboratory of Tibetan Medicine Research Xining P. R. China
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Zhang J, Scott WRP, Gabel F, Wu M, Desmond R, Bae J, Zaccai G, Algar WR, Straus SK. On the quest for the elusive mechanism of action of daptomycin: Binding, fusion, and oligomerization. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1490-1499. [PMID: 28844744 DOI: 10.1016/j.bbapap.2017.07.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/05/2017] [Accepted: 07/31/2017] [Indexed: 01/27/2023]
Abstract
Daptomycin, sold under the trade name CUBICIN, is the first lipopeptide antibiotic to be approved for use against Gram-positive organisms, including a number of highly resistant species. Over the last few decades, a number of studies have tried to pinpoint the mechanism of action of daptomycin. These proposed modes of action often have points in common (e.g. the requirement for Ca2+ and lipid membranes containing a high proportion of phosphatidylglycerol (PG) headgroups), but also points of divergence (e.g. oligomerization in solution and in membranes, membrane perturbation vs. inhibition of cell envelope synthesis). In this study, we investigate how concentration effects may have an impact on the interpretation of the biophysical data used to support a given mechanism of action. Results obtained from small angle neutron scattering (SANS) experiments and molecular dynamics (MD) simulations show that daptomycin oligomerizes at high concentrations (both with and without Ca2+) in solution, but that this oligomer readily falls apart. Photon correlation spectroscopy (PCS) experiments demonstrate that daptomycin causes fusion more readily in DMPC/PG membranes than in POPC/PG, suggesting that the latter may be a better model system. Finally, fluorescence and Förster resonance energy transfer (FRET) experiments reveal that daptomycin binds strongly to the lipid membrane and that oligomerization occurs in a concentration-dependent manner. The combined experiments provide an improved framework for more general and rigorous biophysical studies toward understanding the elusive mechanism of action of daptomycin. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
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Affiliation(s)
- Jin Zhang
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Walter R P Scott
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Frank Gabel
- Institut de Biologie Structurale, 41 rue Jules Horowitz, 38027 Grenoble Cedex 1, France; Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
| | - Miao Wu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Ruqaiba Desmond
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - JungHwan Bae
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Giuseppe Zaccai
- Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
| | - W Russ Algar
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
| | - Suzana K Straus
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
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Pritchard M, Jack A, Powell L, Sadh H, Rye P, Hill K, Thomas D. Alginate oligosaccharides modify hyphal infiltration ofCandida albicansin anin vitromodel of invasive human candidosis. J Appl Microbiol 2017. [DOI: 10.1111/jam.13516] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- M.F. Pritchard
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | - A.A. Jack
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | - L.C. Powell
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | - H. Sadh
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | | | - K.E. Hill
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | - D.W. Thomas
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
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The antimicrobial effects of the alginate oligomer OligoG CF-5/20 are independent of direct bacterial cell membrane disruption. Sci Rep 2017; 7:44731. [PMID: 28361894 PMCID: PMC5374485 DOI: 10.1038/srep44731] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 02/13/2017] [Indexed: 12/19/2022] Open
Abstract
Concerns about acquisition of antibiotic resistance have led to increasing demand for new antimicrobial therapies. OligoG CF-5/20 is an alginate oligosaccharide previously shown to have antimicrobial and antibiotic potentiating activity. We investigated the structural modification of the bacterial cell wall by OligoG CF-5/20 and its effect on membrane permeability. Binding of OligoG CF-5/20 to the bacterial cell surface was demonstrated in Gram-negative bacteria. Permeability assays revealed that OligoG CF-5/20 had virtually no membrane-perturbing effects. Lipopolysaccharide (LPS) surface charge and aggregation were unaltered in the presence of OligoG CF-5/20. Small angle neutron scattering and circular dichroism spectroscopy showed no substantial change to the structure of LPS in the presence of OligoG CF-5/20, however, isothermal titration calorimetry demonstrated a weak calcium-mediated interaction. Metabolomic analysis confirmed no change in cellular metabolic response to a range of osmolytes when treated with OligoG CF-5/20. This data shows that, although weak interactions occur between LPS and OligoG CF-5/20 in the presence of calcium, the antimicrobial effects of OligoG CF-5/20 are not related to the induction of structural alterations in the LPS or cell permeability. These results suggest a novel mechanism of action that may avoid the common route in acquisition of resistance via LPS structural modification.
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Miao J, Liu G, Ke C, Fan W, Li C, Chen Y, Dixon W, Song M, Cao Y, Xiao H. Inhibitory effects of a novel antimicrobial peptide from kefir against Escherichia coli. Food Control 2016. [DOI: 10.1016/j.foodcont.2016.01.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Tang W, Zhang H, Wang L, Qian H. New cationic antimicrobial peptide screened from boiled-dried anchovies by immobilized bacterial membrane liposome chromatography. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:1564-71. [PMID: 24499191 DOI: 10.1021/jf4052286] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
An efficient immobilized bacterial membrane liposome chromatography method was used to screen potential antimicrobial peptides from boiled-dried anchovies. A novel cationic antimicrobial peptide (Apep10) was successfully isolated by one-step chromatography. The sequence of Apep10 was identified as GLARCLAGTL by matrix-assisted laser desorption/ionization quadrupole time-of-flight tandem mass spectrometry (MALDI-Q-TOF MS). The antimicrobial activity assessment indicated that Apep10 inhibited the growth of the reference bacteria (Escherichia coli, Shigella dysenteriae, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, Bacillus subtilis, and Streptococcus pneumoniae), with minimal inhibitory concentration (MIC) values ranging from 8 to 64 μg/mL. Almost no cytotoxicity against mouse erythrocytes was observed at concentrations below 20 μg/mL. Nucleotide leakage induced by Apep10 showed that the peptide exhibited permeable activity on the cytoplasmic membrane. Alterations in morphology were observed by scanning electronic microscopy (SEM). Membrane disruption was confirmed by confocal laser scanning microscopy (CLSM) with propidium iodide (PI). The results demonstrate that immobilized bacterial membrane liposome chromatography is a straightforward technique for screening unknown antimicrobial peptides with cell-membrane-interacting activities from boiled-dried anchovies.
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Affiliation(s)
- Wenting Tang
- State Key Laboratory of Food Science and Technology & School of Food Science and Technology, Jiangnan University , Wuxi 214122, People's Republic of China
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Madhongsa K, Pasan S, Phophetleb O, Nasompag S, Thammasirirak S, Daduang S, Taweechaisupapong S, Lomize AL, Patramanon R. Antimicrobial action of the cyclic peptide bactenecin on Burkholderia pseudomallei correlates with efficient membrane permeabilization. PLoS Negl Trop Dis 2013; 7:e2267. [PMID: 23785532 PMCID: PMC3681726 DOI: 10.1371/journal.pntd.0002267] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 05/01/2013] [Indexed: 01/05/2023] Open
Abstract
Burkholderia pseudomallei is a category B agent that causes Melioidosis, an acute and chronic disease with septicemia. The current treatment regimen is a heavy dose of antibiotics such as ceftazidime (CAZ); however, the risk of a relapse is possible. Peptide antibiotics are an alternative to classical antibiotics as they exhibit rapid action and are less likely to result in the development of resistance. The aim of this study was to determine the bactericidal activity against B. pseudomallei and examine the membrane disrupting abilities of the potent antimicrobial peptides: bactenecin, RTA3, BMAP-18 and CA-MA. All peptides exhibited >97% bactericidal activity at 20 µM, with bactenecin having slightly higher activity. Long term time-kill assays revealed a complete inhibition of cell growth at 50 µM bactenecin and CA-MA. All peptides inhibited biofilm formation comparable to CAZ, but exhibited faster kinetics (within 1 h). Bactenecin exhibited stronger binding to LPS and induced perturbation of the inner membrane of live cells. Interaction of bactenecin with model membranes resulted in changes in membrane fluidity and permeability, leading to leakage of dye across the membrane at levels two-fold greater than that of other peptides. Modeling of peptide binding on the membrane showed stable and deep insertion of bactenecin into the membrane (up to 9 Å). We propose that bactenecin is able to form dimers or large β-sheet structures in a concentration dependent manner and subsequently rapidly permeabilize the membrane, leading to cytosolic leakage and cell death in a shorter period of time compared to CAZ. Bactenecin might be considered as a potent antimicrobial agent for use against B. pseudomallei. Burkholderia pseudomallei is a category B agent that causes Melioidosis, an acute and chronic disease with septicemia. The current treatment regimen is a heavy dose of antibiotics such as ceftazidime (CAZ), however, the risk of a relapse is possible. In this study we demonstrate that bactenecin, CA-MA, RTA3 and BMAP-18 are able to inhibit the growth and biofilm formation of B. pseudomallei. The strong bactericidal activity of bactenecin is attributed to its greater ability to permeabilize the membrane. Computational modeling of these peptide-membrane interactions provide support for a model in which bactenecin is able to penetrate the membrane most effectively due to its cyclical structure. The peptide, bactenecin has the potential to act as a highly effective alternative to CAZ, or as a combination therapy with CAZ in the treatment of melioidosis. Furthermore, understanding the mechanism of bactenecin may help us better design more effective peptides therapeutics of choice for melioidosis.
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Affiliation(s)
- Kanjana Madhongsa
- Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
| | - Supaluk Pasan
- Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
| | - Onanong Phophetleb
- Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
| | - Sawinee Nasompag
- Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
| | - Sompong Thammasirirak
- Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
| | - Sakda Daduang
- Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
| | - Suwimol Taweechaisupapong
- Melioidosis Research Center, Khon Kaen University, Khon Kaen, Thailand
- Biofilm Research Group, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Andrei L. Lomize
- College of Pharmacy, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Rina Patramanon
- Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
- * E-mail:
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Role of molecular architecture on the relative efficacy of aurein 2.5 and modelin 5. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2094-102. [PMID: 22617856 DOI: 10.1016/j.bbamem.2012.05.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 05/11/2012] [Accepted: 05/14/2012] [Indexed: 11/22/2022]
Abstract
In order to gain an insight into the mechanism of antimicrobial peptide action, aurein 2.5 and modelin-5 were studied. When tested against Staphylococcus aureus, aurein 2.5 showed approximately 5-fold greater efficacy even though the higher net positive charge and higher helix stability shown by modelin-5 would have predicated modelin-5 to be the more effective antimicrobial. However, in the presence of S. aureus membrane mimics, aurein 2.5 showed greater helical content (75% helical) relative to modelin-5 (51% helical) indicative of increase in membrane association. This was supported by monolayer data showing that aurein 2.5 (6.6mNm(-1)) generated greater pressure changes than modelin-5 (5.3mNm(-1)). Peptide monolayers indicted that modelin-5 formed a helix horizontal to the plane of an asymmetric interface which would be supported by the even distribution of charge and hydrophobicity along the helical long axis and facilitate lysis by non-specific membrane binding. In contrast, a groove structure observed on the surface of aurein 2.5 was predicted to be the cause of enhanced lipid binding (K(d)=75μM) relative to modelin-5 (K(d)=118μM) and the balance of hydrophobicity along the aurein 2.5 long axis supported deep penetration into the membrane in a tilt formation. This oblique orientation generates greater lytic efficacy in high anionic lipid (71%) compared to modelin-5 (32%).
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Schiopu I, Mereuta L, Apetrei A, Park Y, Hahm KS, Luchian T. The role of tryptophan spatial arrangement for antimicrobial-derived, membrane-active peptides adsorption and activity. MOLECULAR BIOSYSTEMS 2012; 8:2860-3. [DOI: 10.1039/c2mb25221j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Dennison SR, Phoenix DA. Effect of cholesterol on the membrane interaction of Modelin-5 isoforms. Biochemistry 2011; 50:10898-909. [PMID: 22082130 DOI: 10.1021/bi201267v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Modelin-5 isoforms were used to gain an insight into the effects of amidation on antimicrobial selectivity. When tested against Escherichia coli, amidation increased toxicity 10-fold (MIC = 31.25 μM) while showing limited increased hemolytic activity (2% lysis). Our results show that both the amidated and non-amidated peptides had a disordered structure in aqueous solution (<18% helical) and folded to form helices at the membrane interface (for example, >43% in the presence of DMPC). The stabilization of the helical structure by amidation has previously been shown to play a key role in increasing antibacterial efficacy. The presence of cholesterol in the membrane increases the packing density (C(s)(-1) values 25-33 mN m(-1)) and so prevents the peptide from forming stable association with the membrane, which is evidenced by the higher binding coefficient (K(d)) in the presence of cholesterol: 57.70 μM for Modelin-5-COOH and 35.64 μM for Modelin-5-CONH(2) compared to the presence of E. coli lipid extract (10 μM), which would prevent local concentration of the peptide at the bilayer interface as seen by reduction in monolayer interaction. This in turn would be predicted to inhibit activity.
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Affiliation(s)
- Sarah R Dennison
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK
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Dennison SR, Phoenix DA. Influence of C-terminal amidation on the efficacy of modelin-5. Biochemistry 2011; 50:1514-23. [PMID: 21241054 DOI: 10.1021/bi101687t] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To gain insight into the effects of amidation on the mechanism of membrane interaction, we studied two peptides modelin-5-COOH and modelin-5-CONH(2) and found they exhibit high surface activities (23.2 and 27.1 mN/m, respectively). When they were tested against Escherichia coli, amidation was seen to increase efficacy approximately 10-fold. Our results demonstrated that both peptides adopted low levels of α-helix in solution (<20%); however, in the presence of E. coli lipid extract, modelin-5-CONH(2) had a greater propensity (69%) than modelin-5-COOH (32%) to generate α-helical structure. The binding coefficient for both peptides was ∼10 μM, and the Hill coefficient approximated 1, suggesting that for both peptides the interactions with E. coli membranes were monomeric and comparable in strength. The peptides showed a clear preference for anionic lipid, with monolayer data showing that enhanced levels of helicity were associated with a greater pressure change (∼6 mN/m). Use of fluorescein-phosphatidylethanolamine showed the amidated version was able to generate greater levels of membrane disruption, which was confirmed by thermodynamic analysis. The data would imply that both peptides are able to initially bind to bilayer structures, but upon binding, the amidation stabilizes helix formation. This would be expected to help overcome a key rate-limiting step and generate higher local concentrations of peptide at the bilayer interface, which in turn would be predicted to increase efficacy.
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Affiliation(s)
- Sarah R Dennison
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, U.K
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