title: Interaction of antimicrobial peptide Plantaricin149a and four analogs with lipid bilayers and bacterial membranes.
abstract: The amidated analog of Plantaricin149, an antimicrobial peptide from Lactobacillus plantarum NRIC 149, directly interacts with negatively charged liposomes and bacterial membranes, leading to their lysis. In this study, four Pln149-analogs were synthesized with different hydrophobic groups at their N-terminus with the goal of evaluating the effect of the modifications at this region in the peptide's antimicrobial properties. The interaction of these peptides with membrane models, surface activity, their hemolytic effect on red blood cells, and antibacterial activity against microorganisms were evaluated. The analogs presented similar action of Plantaricin149a; three of them with no hemolytic effect (< 5%) until 0.5 mM, in addition to the induction of a helical element when binding to negative liposomes. The N-terminus difference between the analogs and Plantaricin149a retained the antibacterial effect on S. aureus and P. aeruginosa for all peptides (MIC50 of 19 μM and 155 μM to Plantaricin149a, respectively) but resulted in a different mechanism of action against the microorganisms, that was bactericidal for Plantaricin149a and bacteriostatic for the analogs. This difference was confirmed by a reduction in leakage action for the analogs. The lytic activity of Plantaricin149a is suggested to be a result of the peptide-lipid interactions from the amphipathic helix and the hydrophobic residues at the N-terminus of the antimicrobial peptide.
authors.affiliation: Grupo de Biofísica Molecular "Sérgio Mascarenhas", Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil.
authors.forename: José Luiz
authors.initials: JL
authors.lastname: de Souza Lopes
authors.affiliation: Departamento de Biologia, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors.forename: Denise Cavalcante
authors.initials: DC
authors.lastname: Hissa
authors.affiliation: Departamento de Biologia, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors.forename: Vânia Maria Maciel
authors.initials: VM
authors.lastname: Melo
authors.affiliation: Grupo de Biofísica Molecular "Sérgio Mascarenhas", Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil.
authors.forename: Leila Maria
authors.initials: LM
authors.lastname: Beltramini
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000187:drug effects*; D001430:Bacteriocins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects*; D048191:Lactiplantibacillus plantarum / Q000378:metabolism; D008051:Lipid Bilayers / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D023181:Antimicrobial Cationic Peptides; D001430:Bacteriocins; D008051:Lipid Bilayers; C519206:plantaricin 149
keywords: antimicrobial activity; antimicrobial peptide; calcein leakage; hemolytic assay