A neutron study of the feline leukaemia virus fusion peptide: Implications for biological fusion?

Neutron diffraction studies were performed on stacked phospholipid bilayers to determine the effects of the feline leukaemia virus (FeLV) fusion peptide on membrane structure. Bilayers were composed of dioleoylphosphatidylcholine with 50% (mol) dioleoylphosphatidylglycerol. Neutron scattering profiles with peptide present showed an increase in scattering density in the lipid-tails region, whilst scattering by the lipid headgroup region was decreased. This is interpreted as a lowering of the packing density of the lipid headgroups and an increase in the packing density of the lipid tails. Modelling studies and experimental evidence have suggested that fusion peptides catalyse fusion by increasing the negative curvature of the target membrane's outer monolayer. Our results presented here add support to this hypothesis for the fusion mechanism. The (H2O)-H-2 scattering profile was also slightly perturbed in the lipid headgroup region with 1% (mol) FeLV fusion peptide present. The FeLV peptide had no significant effect on the organisation of bilayers containing only dioleoylphosphatidylcholine. (C) 1998 Elsevier Science B.V. All rights reserved.