title: Brevibacillin, a cationic lipopeptide that binds to lipoteichoic acid and subsequently disrupts cytoplasmic membrane of Staphylococcus aureus.
abstract: Brevibacillin is a newly-discovered antimicrobial lipopeptide produced by Brevibacillus laterosporus OSY-I1. It is active against Gram-positive bacteria, including antibiotic resistant strains. This research was initiated to investigate the mechanism of action of brevibacillin against an indicator strain, Staphylococcus aureus ATCC 6538. Results of the study proved that brevibacillin binds to lipoteichoic acid (LTA) on cell wall before interacting with cell membrane. Additionally, brevibacillin disrupts S. aureus cytoplasmic membrane by increasing its permeability, depolarization and potassium leakage. Therefore, cytoplasmic membrane serves as a major target for brevibacillin. Despite the presence of multiple sites on S. aureus cell envelope, scanning electron microscope observation didn't reveal evidence of cell lysis or any morphological defects in cells treated with brevibacillin. Based on the results of this study, we propose that the electrostatic interaction between the cationic brevibacillin and the anionic LTA helped the accumulation of the antimicrobial agent at cell surface; this was followed by translocation of the lipopeptide to the cytoplasmic membrane and disrupting its vital functions.
authors.affiliation: Department of Food Science and Technology, The Ohio State University, Columbus, OH, United States.
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.
authors.forename: En
authors.initials: E
authors.lastname: Huang
authors.affiliation: Department of Food Science and Technology, The Ohio State University, Columbus, OH, United States; Department of Microbiology, The Ohio State University, Columbus, OH, United States. Electronic address: yousef.1@osu.edu.
authors.forename: Ahmed E
authors.initials: AE
authors.lastname: Yousef
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D058675:Brevibacillus / Q000737:chemistry*; D002462:Cell Membrane / Q000187:drug effects* / Q000502:physiology; D055666:Lipopeptides / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D010539:Permeability / Q000187:drug effects; D011485:Protein Binding; D013211:Staphylococcus aureus / Q000187:drug effects*; D013682:Teichoic Acids / Q000378:metabolism*
chemical_list: D023181:Antimicrobial Cationic Peptides; D055666:Lipopeptides; D008070:Lipopolysaccharides; D013682:Teichoic Acids; C009900:lipoteichoic acid
keywords: Brevibacillin; Cytoplasmic membrane; Lipoteichoic acid; Scanning electron microscopy