Design of Trp-Rich Dodecapeptides with Broad-Spectrum Antimicrobial Potency and Membrane-Disruptive Mechanism

J Med Chem. 2019 Aug 8;62(15):6941-6957. doi: 10.1021/acs.jmedchem.9b00288. Epub 2019 Jul 18.

Abstract

There has recently been great concern regarding antibiotics due to potential drug resistance and the impact of antibiotics on the environment. Antimicrobial peptides are believed to have potential as novel antimicrobial agents to address the problems of antibiotics. Herein, we report a set of Trp-rich dodecapeptides derived from PMAP-36 that are based on the peptide folding principle and the amino acid characteristics. An effective peptide design template, (WXYX)3, where X represents Arg or Lys and Y represents hydrophobic or neutral amino acid, was summarized with the distribution of Trp at H-bond formation sites along the α-helical structure. The template peptide 6 (3W-2), with low amphipathicity, displayed strong antimicrobial activity against laboratory strains and clinical isolates while showing no cytotoxicity. Furthermore, 6 was able to suppress the emergence of antimicrobial resistance. Membrane permeabilization assays and microscope observations revealed the potent membrane-disruptive mechanism of 6. Overall, this study diminishes the randomness in peptide design and provides a strategy for generating effective antibiotic alternatives to overcome antibiotic resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / chemical synthesis*
  • Anti-Infective Agents / pharmacology
  • Antimicrobial Cationic Peptides / chemical synthesis
  • Antimicrobial Cationic Peptides / pharmacology
  • Bacterial Outer Membrane / drug effects*
  • Bacterial Outer Membrane / physiology
  • Drug Design*
  • Escherichia coli / drug effects
  • Escherichia coli / physiology
  • Humans
  • Microbial Sensitivity Tests / methods
  • Oligopeptides / chemical synthesis*
  • Oligopeptides / pharmacology
  • Peptide Fragments / chemical synthesis
  • Peptide Fragments / pharmacology
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / physiology
  • Tryptophan / chemical synthesis*
  • Tryptophan / pharmacology

Substances

  • Anti-Infective Agents
  • Antimicrobial Cationic Peptides
  • Oligopeptides
  • PMAP-36
  • Peptide Fragments
  • Tryptophan