Liposome destabilization induced by the HIV-1 fusion peptide effect of a single amino acid substitution.

The 23-residue synthetic peptide representing the N-terminus of HIV-1 gp41 is known to induce either leakage or fusion of lipid vesicles depending on the experimental conditions. In this paper we report that a polar amino acid substitution V-->E at position 2, known to block gp41 activity in vivo, makes the peptide unable to destabilize and/or fuse membranes. Moreover this variant, unlike the parent peptide, is never found in the membrane-associated beta conformation.