Influence Of The Mode Of Insertion Of Siv Peptides Into Membranes On The Structure Of Model Membrane As Studied By P-31 Nmr

The influence on model membrane organization of a fusion peptide of SIV and of a
nonfusogenic mutant of this peptide was examined by molecular modeling and by 31P
NMR. The calculated mode of insertion of the fusion peptide shows that it adopts
an oblique orientation towards the lipid-water interface and that this fusion
peptide induces a destabilization of the bilayer structure of multilamellar
vesicles as evidenced by 31P NMR observations. The SIV mutant showing a more
vertical insertion into lipid layers is unable to induce nonlamellar structures.
This study reinforces the correlation between fusogenic activity, induction of
structures not organized in extended bilayers, and calculated mode of insertion
of peptides into lipid layers.