Study of the electrostatic interactions between peptides and lipids at the membrane interface by molecular dynamics simulation

Charged peptides penetration into a membrane interface is analyzed using molecular dynamics simulation. Peptide having a single charge or two positive charges were presented to an uncharged membrane (a phosphatidyl-choline lipid, FOPC or to a negatively charged membrane (POPC plus a phosphatidyl-serine lipid, POPS). As expected equilibrium peptide penetration into the membrane interface critically depends on both the peptide and membrane charge. Penetration only occurs when the interface is negatively charged and is associated to a well defined transient change in the orientation of the dipole moment of the closest POPS polar heads emphasizing the importance of the very local electrostatic interactions when considering peptide-lipid interactions.