Binding and action of cecropin and cecropin analogues: antibacterial peptides from insects.
The mechanism of action of cecropin was studied by using liposomes as a model system. The bilayer was efficiently destroyed if the liposome net charge was zero or negative. Cecropin analogues with an impaired N-terminal helix had reduced membrane disrupting abilities that correlate with their lower antibacterial activity. The reduced bactericidal activity of the analogues was rationalized in terms of reduced binding to bacteria. The stoichiometry of cecropin killing of bacteria suggests that amounts of cecropin sufficient to form a monolayer strongly modify the bacterial membrane. Although some bacteria were resistant to cecropin they did bind large amounts in a non-productive manner. In contrast, mammalian erythrocytes achieve resistance by avoiding the binding of cecropin.
D000818:Animals; D023181:Antimicrobial Cationic Peptides; D001410:Bacillus megaterium / Q000187:drug effects / Q000378:metabolism; D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004563:Electrochemistry; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism; D006461:Hemolysis; D007301:Insect Hormones / Q000378:metabolism / Q000494:pharmacology*; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D011487:Protein Conformation; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000378:metabolism; D012756:Sheep; D013329:Structure-Activity Relationship
D023181:Antimicrobial Cationic Peptides; D007301:Insect Hormones; D008051:Lipid Bilayers; D008081:Liposomes; C031161:cecropin A