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Role of positively charged residues on the polar and non‐polar faces of amphipathic α‐helical antimicrobial peptides on specificity and selectivity for Gram‐negative pathogens
Author(s) -
Jiang Ziqing,
Mant Colin T.,
Vasil Michael,
Hodges Robert S.
Publication year - 2018
Publication title -
chemical biology and drug design
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.59
H-Index - 77
eISSN - 1747-0285
pISSN - 1747-0277
DOI - 10.1111/cbdd.13058
Subject(s) - acinetobacter baumannii , antimicrobial , antimicrobial peptides , amphiphile , pseudomonas aeruginosa , colistin , biology , staphylococcus aureus , polymyxin , polymyxin b , microbiology and biotechnology , biochemistry , antibiotics , chemistry , bacteria , genetics , organic chemistry , copolymer , polymer
We have designed de novo and synthesized eight 26‐residue all D‐conformation amphipathic α‐helical cationic antimicrobial peptides ( AMP s), four with “specificity determinants” which provide specificity for prokaryotic cells over eukaryotic cells and four AMP s without specificity determinants. The eight AMP s contain six positively charged Lys residues on the polar face in four different arrangements to understand the role of these residues have on antimicrobial activity against 14 Acinetobacter baumannii strains, seven of which were resistant to polymyxin B and colistin; six diverse Pseudomonas aeruginosa strains and 17 Staphylococcus aureus strains, nine of which were methicillin‐sensitive, and eight of which were methicillin‐resistant. The four AMP s without specificity determinants are extremely hemolytic. In contrast, the four AMP s with specificity determinants had dramatic improvements in therapeutic indices showing the importance of specificity determinants in removing eukaryotic cell toxicity. The specificity determinants combined with the location of positively charged residues on the polar face provide Gram‐negative pathogen selectivity between A. baumannii and S. aureus . Specificity determinants maintain excellent antimicrobial activity in the presence of human sera, whereas the AMP s without specificity determinants were inactive. This study clearly shows the potential of amphipathic α‐helical AMP s with specificity determinants as therapeutics to replace existing antibiotics.