title: Design of imperfectly amphipathic α-helical antimicrobial peptides with enhanced cell selectivity.
abstract: Antimicrobial peptides (AMPs), which are produced by multicellular organisms as a defense mechanism against competing pathogenic microbes, appear to be excellent candidates for the development of novel antimicrobial agents. Amphipathicity is traditionally believed to be crucial to the de novo design or systematic optimization of AMPs. In this study, we designed a series of short α-helical AMPs with imperfect amphipathicity to augment the arsenal of strategies and to gain further insights into their antimicrobial and hemolytic activity. These imperfectly amphipathic α-helical AMPs were designed by replacing the paired charged amino acid residues on the polar face of an amphipathic peptide with tryptophan residues on the basis of α-helical protein folding principles. PRW4, an imperfectly amphipathic α-helical AMP with hydrogen bonds formed by paired tryptophan residues, was observed to be more selective towards bacterial cells than toward human red blood cells. PRW4 was also effective against Gram-negative and Gram-positive bacteria, and fluorescence spectroscopy, flow cytometry, scanning electron microscopy and transmission electron microscopy indicated that PRW4 killed microbial cells by permeabilizing the cell membrane and damaging their membrane integrity. Therefore, disruptive amphipathicity has excellent potential for the rational design and optimization of AMPs with promising antimicrobial activities.
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhu
authors.forename: Na
authors.initials: N
authors.lastname: Dong
authors.forename: Zeyun
authors.initials: Z
authors.lastname: Wang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Ma
authors.forename: Licong
authors.initials: L
authors.lastname: Zhang
authors.forename: Qingquan
authors.initials: Q
authors.lastname: Ma
authors.forename: Anshan
authors.initials: A
authors.lastname: Shan
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects / Q000648:ultrastructure; D002463:Cell Membrane Permeability / Q000187:drug effects; D002942:Circular Dichroism; D015195:Drug Design; D005434:Flow Cytometry; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D017433:Protein Structure, Secondary; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D023181:Antimicrobial Cationic Peptides; D012965:Sodium Chloride
keywords: Amphipathicity; Antimicrobial peptides; Bactericidal mechanism; Hemolysis; α-Helix