Epitope mapping of a monoclonal antibody which binds HIV-1 Gag and not the Gag-derived proteins.
Monoclonal antibody (MAb) 1G12 binds the uncleaved HIV-1 Gag polypeptide (p55), but fails to recognize the final products of the proteolytic processing [Sarubbi, E. et al. (1991) FEBS Lett. 279, 265-269]. In this report we show that binding of MAb 1G12 to a 110-residue Gag fragment containing the p17-p24 cleavage site prevents proteolysis of this site by the HIV-1 protease. Competition studies with synthetic peptides have been performed to map the binding site of MAb 1G12 on Gag. The antibody recognizes a sequential epitope that spans the HIV-1 protease cleavage site; determinants located on both p17 and p24 are required for antibody binding. MAb 1G12 is also shown to lack any cross-reactivity with other HIV-1 protease cleavage sites.
Sarubbi
E
E
Lepetit Research Center, Marion Merrell Dow Research Institute, Gerenzano, VA, Italy.
Denaro
M
M
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001667:Binding, Competitive; D015153:Blotting, Western; D003429:Cross Reactions; D000939:Epitopes; D015683:Gene Products, gag / Q000276:immunology* / Q000378:metabolism; D015488:HIV Antigens / Q000276:immunology* / Q000378:metabolism; D016655:HIV Core Protein p24 / Q000276:immunology* / Q000378:metabolism; D016333:HIV Protease / Q000378:metabolism; D015497:HIV-1 / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000276:immunology* / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus
D000911:Antibodies, Monoclonal; D000939:Epitopes; D015683:Gene Products, gag; D015488:HIV Antigens; D016655:HIV Core Protein p24; D011498:Protein Precursors; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1; C059767:p55 gag precursor protein, Human immunodeficiency virus 1; D016333:HIV Protease