Antimicrobial Peptides Containing Unnatural Amino Acid Exhibit Potent Bactericidal Activity against ESKAPE Pathogens

Abstract

A series of 36 synthetic antimicrobial peptides containing unnatural amino acids were screened to determine their effectiveness to treat Enterococcus faecium, Staphylococcus aureus, Klebsiella pnemoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species (ESKAPE) pathogens, which are known to commonly infect chronic wounds. The primary amino acid sequences of these peptides incorporate either three or six dipeptide units consisting of the unnatural amino acids Tetrahydroisoquinolinecarboxylic acid (Tic) and Octahydroindolecarboxylic acid (Oic). The Tic-Oic dipeptide units are separated by SPACER amino acids with specific physicochemical properties that control how these peptides interact with bacterial cell membranes of different chemical compositions. These peptides exhibited minimum inhibitory concentrations (MIC) against these pathogens in the range from >100 to 6.25 lg/mL. The observed diversity of MIC values for these peptides against the various bacterial strains are consistent with our hypothesis that the complementarity of the physicochemical properties of the peptide and the lipid of the bacteria s cell membrane determines the resulting antibacterial activity of the peptide

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2013
Accession Number
ADA614707

Entities

People

  • Johnathan J. Abercrombie
  • Kai P. Leung
  • R. K. Wong
  • R. P. Hicks

Organizations

  • United States Army Institute of Surgical Research

Tags

DTIC Thesaurus Topics

  • Amino Acids
  • Anti-Bacterial Agents
  • Anti-Infective Agents
  • Bacteria
  • Cell Membrane
  • Cells
  • Chemical Composition
  • Chemical Synthesis
  • Chemistry
  • Gram-Negative Bacteria
  • Hydrophobic Properties
  • Infection
  • Mass Spectrometry
  • Membrane Lipids
  • Pathogenic Bacteria
  • Three Dimensional
  • Wound Infections

Fields of Study

  • Biology

Readers

  • Microbial Pathology
  • Molecular and Cellular Biochemistry