Platelet membrane glycoproteins IIb and IIIa are substrates of purified pp60c‐src protein tyrosine kinase

[摘要]

Human platelet glycoproteins IIb and IIIa form the receptor for fibrinogen, von Willebrand factor and fibronectin. Isolated human glycoproteins IIb-IIIa are phosphorylated by purified pp60^c-src protein tyrosine kinase. Analysis of the phosphorylated proteins on SDS-PAGE showed that under reducing conditions both phosphoproteins change their relative molecular masses from 135 to 120 kDa and from 97 to 105 kDa, which are characteristic properties of glycoproteins IIb-IIIa. Phosphorylated proteins could be immunoprecipitated with an antiserum against glycoproteins IIb-IIIa but not by control serum. Some kinetic properties of the glycoprotein phosphorylations are also investigated. How the glycoprotein IIb-IIIa complex acquires its receptor activity in stimulated platelets is unknown; however, phosphorylation could be an important mechanism.

[学科分类] 生物化学/生物物理

[关键词] ppo60c-src;Protein tyrosine kinase;Glycoprotein IIb;Glycoprotein IIIa;Integrin;(Platelet);PTK;protein tyrosine kinase;pp60c-src;the 60 kDa phosphoprotein encoded by the cellular (c-) src-gene;GP IIb-IIIa;glycoproteins IIb and IIIa;SDS-PAGE;SDS-polyacrylamide gel electrophoresis