||Alpha-thrombin is a highly specific serine protease generated by proteolytic activation of the zymogen prothrombin. During coagulation, thrombin cleaves fibrinogen to form fibrin, leading to the ultimate step in coagulation, the formation of a fibrin clot. Thrombin is also responsible for feedback activation of the procofactors factor V and factor VIII. Thrombin has also been reported to activate factor XIII and platelets, and also functions as a vasoconstrictor protein. The procoagulant activity of thrombin is arrested in two ways: 1) inhibition by either heparin cofactor II or the antithrombin III/heparin complex; or 2) complex formation with thrombomodulin. Formation of the thrombin/thrombomodulin complex results in the inability of thrombin to cleave fibrinogen and activate factors V and VIII, but increases the efficiency of thrombin for activation of the anticoagulant, protein C.
||20 mM Hepes, 150 mM NaCl, pH 7.4
||Fibrinogen clotting or chromogenic assay
||>95% by SDS-PAGE. NOT tissue/cell culture grade. Not tested for endotoxin.
||Extinction coefficient:19.5, Percent carbohydrate: approximately 5%, Structure: two subunits, approximately Mr=6,000 and 31,000