Lipid-Specific Interactions with a Fusion Peptide Interacting with Lipid Bilayer Membranes

Fusion peptides (FPs) are small regions of viral proteins that are necessary for infecting a cell. They interact with the cell membrane to allow the virus to enter. Many isolated FPs, such as the 23 amino acid residue peptide from the HIV-1 virus gp41 coat glycoprotien, are capable of causing membrane fusion by themselves. Here, the interaction of an FP derived from the HIV-1 FP with lipid bilayers made from mixtures of lipids were investigated using experiments, including neutron scattering, and molecular dynamics simulations. Not only did the experiments provide new insight into the interaction of the FP with lipid bilayers, but the results also revealed a surprising dependence on the lipid composition. To try to learn the cause of the behavior observed, the systems studied were simulated using all-atom molecular dynamics. The results revealed that the peptide engaged in unanticipated lipid-specific interactions. The work revealed important information about how the FP interacts with lipid bilayer membranes.