title: Characterization of HLA-D-region antigens by two-dimensional gel electrophoresis. Molecular-genotyping.
abstract: Monoclonal antibodies directed against nonpolymorphic determinants of HLA-D/DR molecular complex (human Ia antigens) were used to immunoprecipitate HLA-D-region-associated molecules from [35S]methionine internally labeled and 125I surface-labeled B lymphoblastoid B cell lines. Analysis of these by two-dimensional nonequilibrium-pH-gradient electrophoresis reveals a molecular heterogeneity within a 26,000- to 34,000-mol wt range. At least three sets of spots are identified: a very acidic set of 32,000- to 34,000-mol wt, a very intense invariant spot of 31,000 mol wt, and a series of 26,000- to 29,000-mol wt spots of variable charge. Comparison of immunoprecipitates from nine different HTC demonstrates that the polymorphism is localized in this latter set. Pulse-labeling and inhibition of glycosylation by tunicamycin show that the electrophoretic polymorphism is of polypeptide origin, whereas N-linked oligosaccharrides and sialic acid residues contribute to the microheterogeneity of the profile. Two-dimensional gels provide an electrophoretic genotyping procedure and allow analysis of the genetic organization and molecular complexity of the HLA-D/DR molecules.
mesh_terms: D002460:Cell Line; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D005838:Genotype; D000949:Histocompatibility Antigens Class II / Q000032:analysis / Q000235:genetics*; D006801:Humans; D008214:Lymphocytes / Q000032:analysis
chemical_list: D000949:Histocompatibility Antigens Class II