Analysis of the flexibility and stability of the structure of magainin in a bilayer, and in aqueous and nonaqueous solutions using molecular dynamics simulations.

The precise mode of the antimicrobial activity of Magainin (Mag)-an antimicrobial peptide (AMP)-is still unclear. In this study, the conformation of Mag was characterized in water, and in a methanol and lipid bilayer [palmitoyl-oleoylphosphatidylcholine (POPC)] using a molecular dynamics (MD) simulation technique. To describe the role conformation plays in Mag function, the global conformational differences within three systems were studied. Through analysis of the resulting configuration ensembles, the differences in the three systems, such as overall flexibility and average secondary structure, were studied. It is suggested that these differences may be important enough to influence interactions with lipid biomembranes, thereby influencing key properties such as penetration into cell membrane and stability.