Abstract
Pseudin-2, isolated from the frog Pseudis paradoxa, exhibits potent antibacterial activity but also cytotoxicity. In an effort to develop clinically applicable antimicrobial peptides (AMPs), we designed pseudin-2 analogs with Lys substitutions, resulting in elevated amphipathic α-helical structure and cationicity. In addition, truncated analogs of pseudin-2 and Lys-substituted peptides were synthesized to produce linear 18-residue amphipathic α-helices, which were further investigated for their mechanism and functions. These truncated analogs exhibited higher antimicrobial activity and lower cytotoxicity than pseudin-2. In particular, Pse-T2 showed marked pore formation, permeabilization of the outer/inner bacterial membranes, and DNA binding. Fluorescence spectroscopy and scanning electron microscopy showed that Pse-T2 kills bacterial cells by disrupting membrane integrity. In vivo, wounds infected with multidrug-resistant (MDR) Pseudomonas aeruginosa healed significantly faster when treated with Pse-T2 than did untreated wounds or wounds treated with ciprofloxacin. Moreover, Pse-T2 facilitated infected-wound closure by reducing inflammation through suppression of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α). These data suggest that the small antimicrobial peptide Pse-T2 could be useful for future development of therapeutic agents effective against MDR bacterial strains.
Keywords:
antimicrobial peptide; cell selectivity; membrane disruption; multidrug-resistant bacteria; wound closure.
Copyright © 2018 American Society for Microbiology.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amphibian Proteins / chemical synthesis
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Amphibian Proteins / pharmacology*
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Animals
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Anti-Bacterial Agents / chemical synthesis
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Anti-Bacterial Agents / pharmacology*
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Antimicrobial Cationic Peptides / chemical synthesis
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Antimicrobial Cationic Peptides / pharmacology*
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Anura
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Biofilms / drug effects
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Biofilms / growth & development
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Cell Membrane / drug effects
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Cell Membrane / metabolism
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Ciprofloxacin
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Drug Resistance, Multiple, Bacterial / drug effects
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Drug Resistance, Multiple, Bacterial / genetics
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Escherichia coli / drug effects
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Escherichia coli / growth & development
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Interleukin-1beta / antagonists & inhibitors
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Interleukin-1beta / biosynthesis
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Interleukin-6 / antagonists & inhibitors
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Interleukin-6 / biosynthesis
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Mice
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Mice, Inbred BALB C
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Microbial Sensitivity Tests
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Peptides / chemical synthesis
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Peptides / pharmacology*
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Protein Engineering
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Pseudomonas Infections / drug therapy*
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Pseudomonas Infections / metabolism
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Pseudomonas Infections / pathology
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Pseudomonas aeruginosa / drug effects*
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Pseudomonas aeruginosa / genetics
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Pseudomonas aeruginosa / growth & development
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Skin / drug effects
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Skin / injuries
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Skin / metabolism
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Staphylococcus aureus / drug effects
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Staphylococcus aureus / growth & development
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Structure-Activity Relationship
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Tumor Necrosis Factor-alpha / antagonists & inhibitors
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Tumor Necrosis Factor-alpha / biosynthesis
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Wound Healing / drug effects
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Wounds, Nonpenetrating / drug therapy*
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Wounds, Nonpenetrating / metabolism
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Wounds, Nonpenetrating / pathology
Substances
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Amphibian Proteins
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Anti-Bacterial Agents
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Antimicrobial Cationic Peptides
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IL1B protein, mouse
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Interleukin-1beta
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Interleukin-6
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Peptides
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Tumor Necrosis Factor-alpha
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interleukin-6, mouse
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pseudin-2 protein, Pseudis paradoxa
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Ciprofloxacin