Mode of Action of the Enhancer Peptide NP4P for Membrane-Disruptive Anti-Microbial Peptides

摘要

NP4P is a semi-synthetic peptide derived from a natural, non-antimicrobial peptide fragment (pro-region of nematode cecropin P4) by substitution of all acidic amino acid residues with amides (i.e., Glu -> Gln, and Asp ->Asn). NP4P remarkably enhanced the bactericidal activities of membrane-disrupting antimicrobial peptides (ASABF-a, polymyxin B, and nisin) in vitro, whereas NP4P was not bactericidal and did not interfere with bacterial growth at ≤300 μg/mL. In contrast, the activities of antimicrobial agents with a distinct mode of action (indolicidin, ampicillin, kanamycin, and enrofloxacin) were unaffected. Although the membrane-disrupting activity of NP4P was slight or undetectable, ASABF-a permeabilized S. aureus membranes with enhanced efficacy in the presence of NP4P.