Identification of PlAl alloantigen domain on a 66 kDa protein derived from glycoprotein IIIa of human platelets.
Incubation of platelets with chymotryptin leads to the exposure of fibrinogen receptors and to the appearance of a 66 kDa membrane component on the surface of platelets. Both glycoprotein IIIa (GP IIIa) and a 66 kDa component were precipitated from detergent extracts of solubilized, surface radiolabeled chymotrypsin-treated platelets by human anti-PlAl antisera. Moreover, the presence of the P1A1 antigen was identified on GP IIIa (but not on GP IIb) and on a 66 kDa protein by means of immunoblot procedures using platelet Triton X-114 extracts and these purified proteins. Anti-PlAl antiserum did not recognize GP IIIa on the surface of intact (untreated) platelets nor the 66 kDa protein on the surface of chymotrypsin-treated platelets of PlAl-negative individuals. The present data demonstrate directly that the 66 kDa protein is derived from GP IIIa and contains the PlAl alloantigen.
D016824:Antigens, Human Platelet; D002918:Chymotrypsin / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D007106:Immune Sera; D007163:Immunosorbent Techniques; D039661:Integrin beta3; D007519:Isoantigens / Q000032:analysis*; D008565:Membrane Proteins / Q000032:analysis*; D008970:Molecular Weight; D017830:Octoxynol; D010980:Platelet Membrane Glycoproteins; D011092:Polyethylene Glycols; D011956:Receptors, Cell Surface / Q000378:metabolism
D016824:Antigens, Human Platelet; D006023:Glycoproteins; C061248:ITGB3 protein, human; D007106:Immune Sera; D039661:Integrin beta3; D007519:Isoantigens; D008565:Membrane Proteins; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40; D002918:Chymotrypsin