Molecular dynamics simulations of hydrophobic and amphiphatic proteins interacting with a lipid bilayer membrane

Molecular dynamics simulations of polypeptides at high dilution near a fully hydrated bilayer membrane have been performed. In contrast to previous theoretical predictions, Monte Carlo simulations and conclusions from experiments a spontaneous insertion of amphiphatic or hydrophobic proteins into a membrane is not observed. Rather it is found that an amphiphatic chain has the tendency to remain in proximity to the membrane surface, whereas the location of a hydrophobic chain is more unbound. This is shown using two proteins, melittin and polyleucine. The conformation of the proteins and their orientation with respect to the membrane surface are discussed.