Amyloidogenicity and lipid interaction of antimicrobial anuran peptides

Uperin 3.x antimicrobial peptides, which can also form amyloid-like fibrils, are appropriate to study the effect of salt concentration and cationic to hydrophobic residue substitution on fibril- formation propensity of antimicrobial peptides. Sodium chloride promotes uperin 3.5 aggregation by screening electrostatic repulsion, and initially facilitating increased alpha- helical content. Uperin 3.x peptides and seventh-position alanine variants interacted more favourably with sodium dodecyl sulphate micelles than with dodecyl phosphatidylcholine micelles, with interaction of wild-type peptides being stronger. Peptide aggregates solely composed of coil and turn structures demonstrated relatively rapid beta-aggregation than other aggregates. Alanine substitution increases aggregation propensity of uperin 3.x peptides.