Steric relationship of amino-terminal and carboxy-terminal domains of murine interferon-gamma as assessed by monoclonal antibodies.
Spleen cells from a hamster immunized with murine interferon-gamma (IFN-gamma) carboxy-terminal (95-133) synthetic peptide [IFN-gamma (95-133)] conjugated to keyhole limpet hemocyanin (KLH) were fused with mouse myeloma cells, resulting in the production of an anti-IFN-gamma (95-133) monoclonal antibody, which reacted with IFN-gamma. This monoclonal antibody bound [125I]IFN-gamma in a dose-dependent and reversible fashion, and neutralized the antiviral and macrophage priming activities of IFN-gamma. Antibody-antibody competition for [125I]IFN-gamma binding, using this carboxy-terminal-specific antibody and two previously described amino-terminal-specific monoclonal antibodies, indicated that the carboxy-terminal-specific monoclonal antibody competed only with itself and that the two amino-terminal-specific monoclonal antibodies similarly competed only with each other for [125I]IFN-gamma. The data suggest that the amino- and carboxy-terminal IFN-gamma domains important for function are sterically distant from one another, and suggest the intriguing possibility that interaction of IFN-gamma with its receptor may involve more than one binding site on the IFN-gamma molecule.
D000818:Animals; D000911:Antibodies, Monoclonal; D006224:Cricetinae; D005260:Female; D007371:Interferon-gamma / Q000032:analysis*; D011487:Protein Conformation; D011863:Radioimmunoassay; D011994:Recombinant Proteins
D000911:Antibodies, Monoclonal; D011994:Recombinant Proteins; D007371:Interferon-gamma