The interactions of the N-terminal fusogenic peptide of HIV-1 gp41 with neutral phospholipids

Abstract

We have studied the interactions with neutral phospholipid bilayers of FPI, the 23-residue fusogenic N-terminal peptide of the HIV-1(LAI) transmembrane glycoprotein gp41, by CD, EPR, NMR, and solid state NMR (SSNMR) with the objective of understanding how it lyses and fuses cells. Using small unilamellar vesicles made from egg yolk phoshatidylcholine which were not fused or permeabilised by the peptide we obtained results suggesting that it was capable of inserting as an α-helix into neutral phospholipid bilayers but was only completely monomeric at peptide/lipid (P/L) ratios of 1/2000 or lower. Above this value, mixed populations of monomeric and multimeric forms were found with the proport..