Abstract
The folding of HIV gp41 into a 6-helix bundle drives virus-cell membrane fusion. To examine the structural relationship between the 6-helix bundle core domain and other regions of gp41, we expressed in Escherichia coli, the entire ectodomain of HIV-2(ST) gp41 as a soluble, trimeric maltose-binding protein (MBP)/gp41 chimera. Limiting proteolysis indicated that the Cys-591-Cys-597 disulfide-bonded region is outside a core domain comprising two peptides, Thr-529-Trp-589 and Val-604-Ser-666. A biochemical examination of MBP/gp41 chimeras encompassing these core peptides indicated that the N-terminal polar segment, 521-528, and C-terminal membrane-proximal segment, 658-666, cooperate in stabilizing the ectodomain. A functional interaction between sequences outside the gp41 core may contribute energy to membrane fusion.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Carrier Proteins / chemistry
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Carrier Proteins / genetics
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Chromatography, Gel
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Cysteine / chemistry
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Cysteine / genetics
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Gene Expression
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HIV Envelope Protein gp41 / biosynthesis*
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HIV Envelope Protein gp41 / chemistry*
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HIV Envelope Protein gp41 / genetics
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HIV-2 / chemistry*
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Hot Temperature
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Humans
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Maltose-Binding Proteins
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Molecular Sequence Data
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Peptide Fragments / chemistry
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Protein Denaturation
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Protein Structure, Quaternary
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Protein Structure, Secondary
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Protein Structure, Tertiary
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Recombinant Fusion Proteins / biosynthesis
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / genetics
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Sequence Alignment
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Spectrometry, Mass, Electrospray Ionization
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Ultracentrifugation / methods
Substances
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Carrier Proteins
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HIV Envelope Protein gp41
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Maltose-Binding Proteins
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Peptide Fragments
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Recombinant Fusion Proteins
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Cysteine