T. Suarez et al., The pre-transmembrane region of the human immunodeficiency virus type-1 glycoprotein: a novel fusogenic sequence, FEBS LETTER, 477(1-2), 2000, pp. 145-149
We have investigated membrane interactions and perturbations induced by NH2
-DKWASLWNWFNITNWL-WYIK-COOH (HIVc), representing the membrane interface-par
titioning region that precedes the transmembrane anchor of the human immuno
deficiency virus type-1 gp41 fusion protein. The HIVc peptide bound with hi
gh affinity to electrically neutral vesicles composed of dioleoylphosphatid
ylcholine, dioleoylphosphatidylethanolamine and cholesterol (molar ratio, 1
:1:1), and induced vesicle leakage and lipid mixing. Infrared spectra sugge
st that these effects were promoted by membrane-associated peptides adoptin
g an alpha-helical conformation. A sequence representing a defective gp41 p
henotype unable to mediate both cell-cell fusion and virus entry, was equal
ly unable to induce vesicle fusion, and adopted a non-helical conformation
in the membrane. We conclude that membrane perturbation and adoption of the
alpha-helical conformation by this gp41 region might be functionally meani
ngful. (C) 2000 Federation of European Biochemical Societies. Published by
Elsevier Science B.V. All rights reserved.