[Thrombin: a multifunctional enzyme].
Thrombin is the final enzyme of blood coagulation cascade. It belongs to the trypsin family of serine proteases. Its two primary actions are to cleave fibrinogen to release fibrin and to activate platelets through a limited proteolysis of a specific receptor. In addition, thrombin is the major regulator of blood coagulation. It is both a procoagulant enzyme in the activation of factors V and VIII, and an anticoagulant enzyme through the activation of protein C and TAFI. This multi-functionality of thrombin depends upon the conformation of its active site: depth for high specificity and shape for a finely tuned selection of substrates. Since new anticoagulant molecules, some with anti-thrombin activity, are emerging, it is important to understand the mechanisms allowing thrombin to be so specifically multifunctional.
Polack
B
B
Service d'hématologie biologique, CHU de Grenoble, BP 217, 38043 Grenoble cedex 9. BPolack@chu-grenoble.fr
D000925:Anticoagulants / Q000378:metabolism; D001665:Binding Sites; D001777:Blood Coagulation; D005340:Fibrinogen / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D013379:Substrate Specificity; D013917:Thrombin / Q000737:chemistry / Q000378:metabolism*
D000925:Anticoagulants; D005340:Fibrinogen; D013917:Thrombin