title: Glycoprotein V hydrolysis by thrombin. Lack of correlation with secretion.
abstract: Platelet membrane glycoprotein V (GPV) was hydrolyzed during thrombin-induced platelet aggregation releasing a fragment GPVfl into the supernatant. Hydrolysis of GPV required catalytically active thrombin and was diminished by chemical modification of the fibrinogen binding site of thrombin. Half-maximal liberation of GPVfl occurred at a 10-fold higher concentration of thrombin than was required for half-maximal release. Time course studies at several thrombin concentrations showed disparate release of GPVfl and thrombospondin. These results emphasize the complexity of the initial events in thrombin-induced platelet activation.
authors.forename: G C
authors.initials: GC
authors.lastname: White
authors.forename: C L
authors.initials: CL
authors.lastname: Knupp
mesh_terms: D001665:Binding Sites; D001792:Blood Platelets / Q000378:metabolism*; D002918:Chymotrypsin / Q000378:metabolism; D003594:Cytoplasmic Granules / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D008565:Membrane Proteins / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins; D013917:Thrombin / Q000378:metabolism*; D019699:Thrombospondins
chemical_list: D006023:Glycoproteins; D008565:Membrane Proteins; D010980:Platelet Membrane Glycoproteins; D019699:Thrombospondins; D005340:Fibrinogen; D002918:Chymotrypsin; D013917:Thrombin