First High-Resolution Structures of Antimicrobial Peptides Reveal Important Structural Features

Structures of antimicrobial peptides piscidins 1 and 3 were solved in two bacterial cell mimics by oriented sample solid-state NMR. A significant finding of this work is that in contrast to the ideal structures shown in mechanistic studies of AMPs, the structures of both peptides are disrupted and kinked at a conserved central glycine, which results in stronger interactions with the lipid bilayers. The more pronounced imperfect amphipathicity of piscidin 1 over piscidin 3 that is revealed helps better understand why the former more effectively mixes the lipids as needed to induce the greatest damage to bacterial cells.