title: Demonstration of structural polymorphism among MB3 light chains by two-dimensional gel electrophoresis.
abstract: The heavy and light chain subunits of MB3 molecules were isolated from KT2 (DKT2, DR4, MB3 homozygous), ER (Dw4, DR4, MB3 homozygous), JMe (Dw5, DR5, MB3 homozygous), EBV-Sh (DSh, DRw6.2, MB3 homozygous), and EBV-Ky (DKy, DRw9, MB3 homozygous) cells and were compared with one another by two-dimensional gel electrophoresis. The MB3 light chains from KT2, ER, and EBV-Ky cells were clearly different in terms of their isoelectric points, whereas those from ER, JMe, and EBV-Sh cells were indistinguishable. No differences in charge or m.w. were noted for the MB3 heavy chains from the five cell lines. Thus, three out of the five MB3-positive, D/DR-disparate cell lines were found to express structurally distinct MB3 molecules, demonstrating that MB3 is a public serologic specificity shared by at least three structurally distinct MB (human I-A-like) molecules. Because the DR light chain subunits isolated from EBV-Wa, KT2, ER, JMe, EBV-Sh, and EBV-Ky cells differed from one another in their isoelectric points, the DR light chains were apparently more polymorphic than the MB3 light chains.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D006680:HLA Antigens / Q000235:genetics; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000302:isolation & purification; D006720:Homozygote; D006801:Humans; D007519:Isoantigens / Q000235:genetics* / Q000302:isolation & purification; D007945:Leukemia, Lymphoid / Q000276:immunology; D046911:Macromolecular Substances; D010641:Phenotype; D011110:Polymorphism, Genetic
chemical_list: D006680:HLA Antigens; D000949:Histocompatibility Antigens Class II; D007519:Isoantigens; D046911:Macromolecular Substances