title: A novel idiotopic determinant on phosphorylcholine-binding immunoglobulins restricted to isotype and allotype.
abstract: A shared idiotopic (Id) determinant, designated B24-50, was detected on phosphorylcholine (PC)-binding myeloma proteins by using a monoclonal antibody. Analysis of immune sera from inbred and congenic strains of mice revealed the presence of this Id determinant on a very small proportion of the PC-binding immunoglobulins (Ig). Hybridoma and myeloma proteins of various classes were analyzed for B24-50 expression, and a clear association of B24-50 with IgA was demonstrated. The Id was found on two distinct idiotypic families, (TEPC15 and McPC603), which share a similar heavy chain but have different light chains; however, isolated heavy chains did not express B24-50. The Id did not require the absolute association of the TEPC15 light chain V kappa 22 with the TEPC15 heavy chain but appeared dependent upon the interaction of the light chain with the TEPC15 heavy chain via quaternary interactions and/or shared amino acid residues of V kappa 8 (M603) and V kappa 22. Furthermore, B24-50 was not found on IgA of strains with the Ighb allotype. Thus B24-50 is a novel isotype-restricted determinant found on two Id families and is influenced by the Igh allotype.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002794:Choline / Q000031:analogs & derivatives*; D007126:Immunoglobulin Allotypes / Q000276:immunology*; D007127:Immunoglobulin Constant Regions / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000276:immunology*; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D007147:Immunoglobulin Light Chains / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000276:immunology; D007137:Immunoglobulin alpha-Chains / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D010767:Phosphorylcholine / Q000276:immunology*
chemical_list: D007126:Immunoglobulin Allotypes; D007127:Immunoglobulin Constant Regions; D007143:Immunoglobulin Heavy Chains; D007130:Immunoglobulin Idiotypes; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D007137:Immunoglobulin alpha-Chains; D010767:Phosphorylcholine; D002794:Choline