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A molecular model for membrane fusion based on solution studies of an amphiphilic peptide from HIV gp41
Author(s) -
Fujii Gary,
Horvath Suzanna,
Woodward Susan,
Eiserling Fred,
Eisenberg David
Publication year - 1992
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.5560011107
Subject(s) - gp41 , human immunodeficiency virus (hiv) , amphiphile , peptide , fusion , lipid bilayer fusion , membrane , chemistry , computational biology , biophysics , virology , biochemistry , medicine , biology , genetics , organic chemistry , philosophy , polymer , antigen , copolymer , epitope , linguistics
The mechanism of protein‐mediated membrane fusion and lysis has been investigated by solution‐state studies of the effects of peptides on liposomes. A peptide (SI) corresponding to a highly amphiphilic C‐terminal segment from the envelope protein (gp41) of the human immunodeficiency virus (HIV) was synthesized and tested for its ability to cause lipid membranes to fuse together (fusion) or to break open (lysis). These effects were compared to those produced by the lytic and fusogenic peptide from bee venom, melittin. Other properties studied included the changes in visible absorbance and mean particle size, and the secondary structure of peptides as judged by CD spectroscopy. Taken together, the observations suggest that protein‐mediated membrane fusion is dependent not only on hydrophobic and electrostatic forces but also on the spatial arrangement of the amino acid residues to form an amphiphilic structure that promotes the mixing of the lipids between membranes. A speculative molecular model is proposed for membrane fusion by α ‐helical peptides, and its relationship to the forces involved in protein‐membrane interactions is discussed.