HLA-DR antigens have polymorphic light chains and invariant heavy chains as assessed by lysine-containing tryptic peptide analysis.
HLA-DR antigens were isolated from B lymphoblastoid cells labeled with either [3H]- or [14C]lysine. Double-label comparisons of the tryptic peptides by microbore ion-exchange chromatography led to the following conclusions: The heavy and light chains share few peptides, one of which is free lysine that is liberated from the polypeptide chains by trypsin. The heavy chains of different HLA-DR allospecificities are virtually identical in all cell lines examined. In contrast, the light chains of different HLA-DR allospecificities are nonidentical and, thus, must bear the alloantigenic determinant.
D001402:B-Lymphocytes / Q000276:immunology; D002460:Cell Line; D055598:Chemical Phenomena; D002621:Chemistry; D002852:Chromatography, Ion Exchange; D006023:Glycoproteins / Q000032:analysis; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D008239:Lysine / Q000378:metabolism; D010455:Peptides / Q000235:genetics; D011110:Polymorphism, Genetic; D011487:Protein Conformation
D006023:Glycoproteins; D000949:Histocompatibility Antigens Class II; D010455:Peptides; D008239:Lysine