title: Localisation of the monocyte-binding region on human immunoglobulin G.
abstract: Earlier studies, which provided indirect evidence for the involvement of the C gamma 2 domain of human immunoglobulin G (IgG) in human immunoglobulin G (IgG) in human monocyte binding, have been extended to further localise the site of interaction on human IgG. A number of IgGs from several different species and fragments of human IgGs were assayed for ability to inhibit the interaction of radio-labelled human IgG and the human monocyte. By comparison of the amino-acid sequences of those IgGs found to exhibit relatively tight, intermediate or weak binding to human monocyte Fc receptors we are able to postulate a possible monocyte-binding site on human IgG. In addition, the results have implications for the applicability of monoclonal antibodies and antisera when used in the presence of human monocytes and possibly macrophages.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000915:Antibody Affinity; D001666:Binding Sites, Antibody; D002417:Cattle; D003166:Complement Activating Enzymes / Q000276:immunology; D015922:Complement C1q; D006041:Goats; D006168:Guinea Pigs; D006358:Hot Temperature; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D051379:Mice; D009000:Monocytes / Q000276:immunology*; D051381:Rats; D011961:Receptors, Fc / Q000276:immunology*; D012756:Sheep; D013552:Swine
chemical_list: D007074:Immunoglobulin G; D011961:Receptors, Fc; D015922:Complement C1q; D003166:Complement Activating Enzymes