Antimicrobial peptides: pore formers or metabolic inhibitors in bacteria?
Antimicrobial peptides are an abundant and diverse group of molecules that are produced by many tissues and cell types in a variety of invertebrate, plant and animal species. Their amino acid composition, amphipathicity, cationic charge and size allow them to attach to and insert into membrane bilayers to form pores by 'barrel-stave', 'carpet' or 'toroidal-pore' mechanisms. Although these models are helpful for defining mechanisms of antimicrobial peptide activity, their relevance to how peptides damage and kill microorganisms still need to be clarified. Recently, there has been speculation that transmembrane pore formation is not the only mechanism of microbial killing. In fact several observations suggest that translocated peptides can alter cytoplasmic membrane septum formation, inhibit cell-wall synthesis, inhibit nucleic-acid synthesis, inhibit protein synthesis or inhibit enzymatic activity. In this review the different models of antimicrobial-peptide-induced pore formation and cell killing are presented.
Brogden
Kim A
KA
Department of Periodontics and Dows Institute for Dental Research, College of Dentistry, The University of Iowa, Iowa City, Iowa 52242, USA. kim-brogden@uiowa.edu
D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology* / Q000502:physiology; D001419:Bacteria / Q000187:drug effects*; D018407:Bacterial Physiological Phenomena; D002462:Cell Membrane / Q000187:drug effects; D015195:Drug Design; D024881:Drug Resistance, Bacterial / Q000502:physiology; D006801:Humans; D010539:Permeability; D011487:Protein Conformation
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides