Membrane interactions of antimicrobial peptides from Australian tree frogs

• Published in: Biochimica et biophysica acta 2006-09, Vol.1758 (9), p.1178-1183
• Main Authors: Boland, Martin P., Separovic, Frances
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Antibacterial peptides; Anura; Lipid Bilayers; Membranes, Artificial; Model membranes; Models, Chemical; Molecular Sequence Data; Nuclear Magnetic Resonance, Biomolecular; Peptides - chemistry; Peptides - isolation & purification; Peptides - pharmacology; Peptide–lipid interactions; Pore formation; Solid-state NMR; Spectrometry, Fluorescence
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/j.bbamem.2006.02.010

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 α-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.