Destabilization Of A Model Membrane By A Predicted Fusion Peptide Of Fertilin Alpha

The subunit a of the guinea pig fertilin (previously known as PH-30, an
integral membrane protein involved in sperm-egg binding and fusion) is predicted to be a potential fusion protein.The structure of this putative fusion protein was analysed by molecular modeling and we have found a peptidic sequence of 17 residues (D83-P99) organized in helix that inserts obliquely in lipid phases. The effect of ths synthesized peptide was studied on a model membrane by 3lP NMR and light scattering. It appears
to increase the size of lipid vesicles and induces structural odifications. We interpret these observations as a destabilization of the lipid organization by this peptide because of its tilted insertion in phospholipid layers. This destabilization could favor membrane
fusion.