title: Characterization of platelet-specific alloantigens by immunoblotting: localization of Zw and Bak antigens.
abstract: The glycoprotein localization of the platelet-specific antigens Zwa, Zwb and Baka and their presence on tryptic fragments of glycoproteins was studied by immunoblotting. Human platelets were solubilized and pre-cleared from platelet-associated IgG. The glycoproteins were separated on SDS polyacrylamide gels, transferred to nitrocellulose and incubated with platelet antibodies, followed by 125I-radiolabelled anti-human Ig antibodies. Glycoprotein IIb/IIIa were isolated from platelet lysates by immuno-affinity chromatography. These proteins were subjected to trypsin digestion, and then used for the immunoblot procedure with platelet antibodies. A glycoprotein specifically reacting with either anti-Zwa or anti-Zwb was found, with an apparent molecular weight of 88 kDa. This protein co-migrated, and was probably identical with, glycoprotein IIIa. After trypsin digestion the smallest fragment, reactive with IgG anti-Zwa or IgM anti-Zwb, had a molecular weight of approximately 23 kDa. IgG anti-Baka and anti-Leka antibodies reacted with a protein of 130 kDa from platelets of Bak(a+) donors. This protein was identified as glycoprotein IIb.
mesh_terms: D016824:Antigens, Human Platelet; D001792:Blood Platelets / Q000276:immunology*; D006023:Glycoproteins / Q000032:analysis; D006801:Humans; D007118:Immunoassay; D039661:Integrin beta3; D007519:Isoantigens / Q000032:analysis*; D010446:Peptide Fragments / Q000276:immunology; D014357:Trypsin
chemical_list: C044561:3a alloantigen, human; D016824:Antigens, Human Platelet; D006023:Glycoproteins; C061248:ITGB3 protein, human; D039661:Integrin beta3; D007519:Isoantigens; D010446:Peptide Fragments; D014357:Trypsin