title: Lipid membrane-binding properties of tryptophan analogues of linear amphipathic beta-sheet cationic antimicrobial peptides using surface plasmon resonance.
abstract: Using a surface plasmon resonance (SPR) system, we investigated the lipid membrane-binding properties of four analogues of the 18-residue linear amphipathic beta-sheet cationic antimicrobial peptide (KIGAKI)3-NH2, each of which contains a single isoleucine-to-tryptophan substitution. The results of the SPR study revealed significant differences in the binding characteristics of the peptides depending upon the position of tryptophan residues. These peptides showed higher binding affinity to membranes containing acidic phospholipids than zwitterionic phospholipids. The addition of dimethylsulfoxide to the running buffer was effective in maintaining the solubility of these peptide solutions and obtaining concentration-dependent sensorgrams for the kinetic analysis in this study. The kinetic binding data of SPR correlated closely with both the ability of the peptides to lyse liposomes with the same phospholipid composition and bactericidal activity. The results demonstrate that SPR may be a valuable tool to predict the membrane lytic properties of antimicrobial peptides.
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia. hiroshi.kamimori@shionogi.co.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamimori
authors.forename: Jack
authors.initials: J
authors.lastname: Blazyk
authors.forename: Marie-Isabel
authors.initials: MI
authors.lastname: Aguilar
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism*; D008081:Liposomes; D008563:Membrane Lipids / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D017433:Protein Structure, Secondary / Q000502:physiology; D020349:Surface Plasmon Resonance / Q000379:methods*; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D023181:Antimicrobial Cationic Peptides; D008051:Lipid Bilayers; D008081:Liposomes; D008563:Membrane Lipids; D010446:Peptide Fragments; D014364:Tryptophan