Binding and reorientation of melittin in a POPC bilayer: Computer simulations

► Melittin can adopt a shallow “U-shaped” conformation upon binding to a POPC bilayer. ► Reorientation of melittin at a P/L ratio = 1/128 causes water defects in the bilayer. ► At P/L = 4/128, upon reorientation, the water defects form stable toroidal pores. ► Pseudo-transmembrane conformation is an intermediate in the reorientation process.