Not only the nature of peptide but also the characteristics of cell membrane determine the antimicrobial mechanism of a peptide.
The mechanisms of antimicrobial actions of magainin 2, buforin II and poly L-lysine against various Escherichia coli strains were studied. Poly L-lysine inhibited BL21, AD 434 and GroE+/DnaK+ growth without lysing the cell. Magainin 2 had a pore-forming activity on BL 21 and AD 434 membrane but could not inhibit the GroE+/DnaK+ growth in a nutrient-rich medium. Buforin II, which killed BL21 and AD 434 without cell membrane damage, lysed GroE+/DnaK+ to death. Once they were introduced into the cell by electroporation, all three peptides were able to inhibit cell growth at concentrations of 10 times lower than their MICs. These results indicate that the nature of the peptide and also the characteristics of the cell membrane determine the antimicrobial actions of a peptide.
Liang
J F
JF
Department of Biological Sciences and Biotechnology, School of Life Sciences and Engineering, Tsinghua University, Beijing, People's Republic of China. junfeng@umich.edu
Kim
S C
SC
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides; D001412:Bacillus subtilis / Q000187:drug effects / Q000648:ultrastructure; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology*; D004352:Drug Resistance, Microbial; D018274:Electroporation; D004926:Escherichia coli / Q000187:drug effects / Q000648:ultrastructure; D054806:Magainins; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D011107:Polylysine / Q000737:chemistry / Q000494:pharmacology*; D011506:Proteins / Q000737:chemistry / Q000494:pharmacology*; D016958:Pseudomonas putida / Q000187:drug effects / Q000648:ultrastructure; D013329:Structure-Activity Relationship; D029867:Xenopus Proteins
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D054806:Magainins; D010455:Peptides; D011506:Proteins; D029867:Xenopus Proteins; C097849:buforin II; C053301:magainin 2 peptide, Xenopus; D011107:Polylysine