Action of thrombin on surface glycoproteins of human platelets.
We labeled surface glycoproteins of human platelets by the neuraminidase-galactose oxidase/borotritiide and the periodate/borotritiide methods. When labeled platelets were treated with 1-nM thrombin, a minor glycoprotein weighing 68,000-85,000-d was lost from the surface, and a soluble glycoprotein weighing 57,000-68,000-d was found in the supernatant. Treatment of platelets with ADP, collagen, or the calcium ionophore A23187 did not cause loss of the 68,000-85,000-d glycoprotein from platelet surfaces or appearance of the 57,000-68,000-d glycoprotein in the supernatant. However, trace amounts of the intact 68,000-85,000-d glycoprotein were found in the supernatants of platelets that were not treated with thrombin. The numerous effects of thrombin on platelets could be initiated by cleavage and release the thrombin-sensitive glycoprotein.
D001792:Blood Platelets / Q000378:metabolism*; D001894:Borohydrides / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005692:Galactose Oxidase / Q000494:pharmacology; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008970:Molecular Weight; D009439:Neuraminidase / Q000494:pharmacology; D010504:Periodic Acid / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology*
D001894:Borohydrides; D006023:Glycoproteins; D010504:Periodic Acid; D005692:Galactose Oxidase; D009439:Neuraminidase; D013917:Thrombin