title: One interferon gamma receptor binds one interferon gamma dimer.
abstract: We investigated the stoichiometry of the interferon gamma and interferon gamma receptor interaction, using recombinant interferon gamma and recombinant soluble interferon gamma receptor, applying chemical cross-linking and chromatographic techniques, and analyzing the resulting products in denaturing polyacrylamide gels. Interferon gamma cross-linked to itself produced a major band of an apparent molecular mass of 34 kDa, which suggests that it exists as a dimer in physiological buffer and which agrees with published data. Soluble interferon gamma receptor cross-linked to itself produced mainly a 28-kDa band, suggesting that the interferon gamma receptor exists as a monomer. Interferon gamma cross-linked to the soluble interferon gamma receptor resulted in the formation of two main products of apparent molecular masses of 60 and 44 kDa. The predominant 60-kDa band resulted from the cross-linking of one interferon gamma dimer (34 kDa) to one interferon gamma receptor molecule (27 kDa). The 44-kDa band was formed by the cross-linking of one interferon gamma molecule to one interferon gamma receptor. Kinetic studies showed that the cross-linking of interferon gamma dimer to the soluble receptor proceeds through the intermediate formed by cross-linking one molecule of the interferon gamma dimer to the receptor. Reducing and dissociating agents inhibited complex formation. When chromatographed on Sephadex G-100, interferon gamma was eluted as a protein of 34-kDa molecular mass, the soluble interferon gamma receptor as a protein of 40 kDa, and their mixture was eluted in one peak corresponding to an apparent molecular mass of 73 kDa. Sodium dodecyl sulfate-polyacrylamide gel analysis of the eluted mixture showed the presence of both interferon gamma and interferon gamma receptor at a ratio of 2:1. The found results suggest that the interferon gamma receptor binds interferon gamma as a dimer.
authors: Hoffman-La Roche Limited, Central Research Units, Basel, Switzerland.
authors: M
authors: M
authors: Fountoulakis
authors: J F
authors: JF
authors: Juranville
authors: A
authors: A
authors: Maris
authors: L
authors: L
authors: Ozmen
authors: G
authors: G
authors: Garotta
mesh_terms: D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002850:Chromatography, Gel; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007371:Interferon-gamma / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D010084:Oxidation-Reduction; D011487:Protein Conformation; D011971:Receptors, Immunologic / Q000737:chemistry / Q000378:metabolism*; D017471:Receptors, Interferon; D011994:Recombinant Proteins; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013861:Thiocyanates / Q000494:pharmacology
chemical_list: D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D011971:Receptors, Immunologic; D017471:Receptors, Interferon; D011994:Recombinant Proteins; D013861:Thiocyanates; D012967:Sodium Dodecyl Sulfate; C024553:sodium thiocyanate; D007371:Interferon-gamma