[Regulatory mechanism of fibrinolysis system by thrombin activatable fibrinolysis inhibitor (TAFI)].
Thrombin-activatable fibrinolysis inhibitor (TAFI) is a 60-kDa plasma protein that has been shown to be identical to plasma carboxypeptidase B (CPB) and carboxypeptidase U (CPU). TAFI is activated by thrombomodulin (TM)-bound thrombin and specifically removes the C-terminal Lys and Arg by its CPB activity. One of its target substrates is the C-terminal Lys residue in the alpha-chain of plasmin-digested fibrin, which is critical for plasminogen binding to fibrin. Thus, its removal seems to be the main mechanism through which TAFI inhibits fibrinolysis. In this article, relevance of C-terminal Lys of plasmin-digested fibrin in fibrinolysis is described, and then possible roles of TAFI and TM-bound thrombin in a cross-talk between coagulation and fibrinolysis are discussed.
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Department of Physiology, Hamamatsu University School of Medicine, 3600, Handa-cho, Hamamatsu 431-3192, Japan. uranot@hama-med.ac.jp
D001665:Binding Sites; D001777:Blood Coagulation / Q000502:physiology; D025901:Carboxypeptidase B2; D002268:Carboxypeptidases / Q000378:metabolism / Q000502:physiology; D005337:Fibrin / Q000378:metabolism / Q000502:physiology; D005342:Fibrinolysis / Q000502:physiology; D006801:Humans; D008239:Lysine / Q000378:metabolism / Q000502:physiology; D013917:Thrombin / Q000378:metabolism / Q000502:physiology; D018180:Thrombomodulin / Q000378:metabolism / Q000502:physiology
D018180:Thrombomodulin; D005337:Fibrin; D002268:Carboxypeptidases; D025901:Carboxypeptidase B2; D013917:Thrombin; D008239:Lysine