INTERACTIONS OF PRIMARY AMPHIPATHIC VECTOR PEPTIDES WITH MEMBRANES - CONFORMATIONAL CONSEQUENCES AND INFLUENCE ON CELLULAR-LOCALIZATION

The conformations of two peptides produced by the combinations of a nu clear localization sequence and a sequence issued from the fusion prot ein gp41 of HIV 1 have been analyzed both in solution and in membranes or in membrane mimicking environments. Both are shown to be nonordere d in water, alpha-helical when incorporated into SDS micelles where th e helical domain concerns the hydrophobic part of the peptides, Intera ctions with lipids induce the formation of beta-sheet and the lipid-pe ptide interactions are governed by the nature of the lipid polar headg roups, A monolayer study shows that replacement of the sequence separa ting the two sequences with an arginine favors the lipid-peptide inter actions which may contribute to the understanding of the different, nu clear and membrane associated, cellular localizations of the peptides.