Membrane interactions of antimicrobial peptides from Australian tree frogs.
The skin secretions of amphibians are rich in host defence peptides. The membrane interactions of the antimicrobial peptides, aurein 1.2, citropin 1.1 and maculatin 1.1, isolated from Australian tree frogs, are reviewed. Although all three peptides are amphipathic alpha-helices, the mode of action of these membrane-active peptides is not defined. The peptides have a net positive charge and range in length from 13 to 21 residues, with the longest, maculatin 1.1, having a proline at position 15. Interestingly, alanine substitution at Pro-15 leads to loss of activity. The effects of these peptides on phospholipid bilayers indicate different mechanisms for pore formation and lysis of model membranes, with the shorter peptides exhibiting a carpet-like mechanism and the longest peptide forming pores in phospholipid bilayer membranes.
School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne VIC 3010, Australia.
Martin P
MP
Boland
Frances
F
Separovic
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001001:Anura; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D008956:Models, Chemical; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence
D000900:Anti-Bacterial Agents; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010455:Peptides