title: Isolation of a murine leukemia FC receptor by selective release induced by surface redistribution.
abstract: A protein which binds to the Fc region of IgG has been isolated from the murine leukemia L1210. The isolation technique involves surface cross-linking of the cells's Fc receptors with the use of aggregated human IgG and anti-human IgG. This results in the redistribution (patch formation and capping) of the cells's Fc receptors. Lactoperoxidase-catalyzed radioiodination of the cells before complex binding indicates that Fc receptor redistribution results in the selective release of surface proteins. SDS-PAGE analyses of the supernatants from cells thus treated reveals a major peak corresponding to a molecular weight of 45,000 daltons. This protein has been purified from the cell supernatants by immunoprecipitation and chromatography of the percipitates on Sephadex G-200 under dissociating conditions. After separation from the immune complex this protein can be bound to heat-aggregated IgG, but not aggregated F(ab')2 fragments. The 45,000 dalton protein appears to be the Fc receptor which has been released from the cell surface in association with the complex.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D000936:Antigen-Antibody Complex; D001666:Binding Sites, Antibody / Q000302:isolation & purification*; D002462:Cell Membrane / Q000276:immunology; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism; D007074:Immunoglobulin G; D007939:Leukemia L1210 / Q000276:immunology*; D051379:Mice; D008970:Molecular Weight
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000936:Antigen-Antibody Complex; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G