Synthetic peptides and anti-peptide antibodies as probes to study interdomain interactions involved in virus assembly: the envelope of the human immunodeficiency virus (HIV-1).
Synthetic peptides and anti-peptide antibodies have been widely used as probes to map B- and T-cell epitopes on proteins. Such probes also have the potential to delineate contact sites involved generally in protein-protein interactions or in association of domains within a protein. We applied peptide/anti-peptide probes to define: (1) regions on the human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins gp120 and gp41 involved in the association between these two glycoproteins; and (2) sites on gp120/gp41, essential for the association of HIV-1 with the CD4 cell receptor. Results of this examination suggested the following: (1) two segments on gp120, encompassing residues (102-126) and (425-452), contribute to the binding site for CD4 and are expected to be juxtaposed in the folded gp120 chain; (2) portions of immunodominant gp120 and gp41 epitopes, encompassing residues (303-338) and (579-611), respectively, appeared to be involved in the gp120-gp41 association, as suggested by direct binding studies and by the limited accessibility of these epitopes on HIV-1 virions: other portions of gp120 also appeared to contribute to the association between these two glycoproteins; (3) there is a partial overlap between gp41 and CD4 binding sites on gp120; (4) the fusion domain and a segment (637-666) of gp41 are not accessible to antibodies after oligomerization of gp41; and 5) the gp120-gp41 association was blocked by aurintricarboxylic acid, suggesting the possibility of developing antiviral compounds interfering with HIV-1 assembly.
Neurath
A R
AR
Lindsley F. Kimball Research Institute, New York Blood Center, New York 10021.
Strick
N
N
Jiang
S
S
D000595:Amino Acid Sequence; D015153:Blotting, Western; D015704:CD4 Antigens / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D015483:HIV Antibodies / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000276:immunology / Q000502:physiology*; D015700:HIV Envelope Protein gp41 / Q000276:immunology / Q000502:physiology*; D015497:HIV-1 / Q000276:immunology / Q000502:physiology*; D016056:Immunodominant Epitopes / Q000276:immunology / Q000378:metabolism; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D011485:Protein Binding; D011863:Radioimmunoassay
D015704:CD4 Antigens; D000939:Epitopes; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D015700:HIV Envelope Protein gp41; D016056:Immunodominant Epitopes; D010455:Peptides