9cth
From Proteopedia
Preliminary map of the Prothrombin-prothrombinase complex on nano discs
Structural highlights
DiseaseFA5_HUMAN Defects in F5 are the cause of factor V deficiency (FA5D) [MIM:227400; also known as Owren parahemophilia. It is a hemorrhagic diastesis.[1] [2] Defects in F5 are the cause of thrombophilia due to activated protein C resistance (THPH2) [MIM:188055. THPH2 is a hemostatic disorder due to defective degradation of factor Va by activated protein C. It is characterized by a poor anticoagulant response to activated protein C resulting in tendency to thrombosis.[3] [4] [5] [6] [7] Defects in F5 are a cause of susceptibility to Budd-Chiari syndrome (BDCHS) [MIM:600880. A syndrome caused by obstruction of hepatic venous outflow involving either the hepatic veins or the terminal segment of the inferior vena cava. Obstructions are generally caused by thrombosis and lead to hepatic congestion and ischemic necrosis. Clinical manifestations observed in the majority of patients include hepatomegaly, right upper quadrant pain and abdominal ascites. Budd-Chiari syndrome is associated with a combination of disease states including primary myeloproliferative syndromes and thrombophilia due to factor V Leiden, protein C deficiency and antithrombin III deficiency. Budd-Chiari syndrome is a rare but typical complication in patients with polycythemia vera. Defects in F5 may be a cause of susceptibility to ischemic stroke (ISCHSTR) [MIM:601367; also known as cerebrovascular accident or cerebral infarction. A stroke is an acute neurologic event leading to death of neural tissue of the brain and resulting in loss of motor, sensory and/or cognitive function. Ischemic strokes, resulting from vascular occlusion, is considered to be a highly complex disease consisting of a group of heterogeneous disorders with multiple genetic and environmental risk factors.[8] Defects in F5 are associated with susceptibility to pregnancy loss, recurrent, type 1 (RPRGL1) [MIM:614389. RPRGL1 is a common complication of pregnancy, resulting in spontaneous abortion before the fetus has reached viability. The term includes all miscarriages from the time of conception until 24 weeks of gestation. Recurrent pregnancy loss is defined as 3 or more consecutive spontaneous abortions.[9] FunctionFA5_HUMAN Central regulator of hemostasis. It serves as a critical cofactor for the prothrombinase activity of factor Xa that results in the activation of prothrombin to thrombin. Publication Abstract from PubMedThe hemostatic response to vascular injury entails a sequence of proteolytic events where several inactive zymogens of the trypsin family are converted to active proteases. The cascade starts with exposure of tissue factor from the damaged endothelium and culminates with conversion of prothrombin to thrombin in a reaction catalyzed by the prothrombinase complex composed of the enzyme factor Xa, cofactor Va, Ca(2+), and phospholipids. This cofactor-dependent activation is paradigmatic of analogous reactions of the blood coagulation and complement cascades, which makes elucidation of its molecular mechanism of broad significance to the large class of trypsin-like zymogens to which prothrombin belongs. Because of its relevance as the most important reaction in the physiological response to vascular injury, as well as the main trigger of pathological thrombotic complications, the mechanism of prothrombin activation has been studied extensively. However, a molecular interpretation of this mechanism has become available only recently from important developments in structural biology. Here we review current knowledge on the prothrombin-prothrombinase interaction and outline future directions for the study of this key reaction of the coagulation cascade. The Prothrombin-Prothrombinase Interaction.,Stojanovski BM, Mohammed BM, Di Cera E Subcell Biochem. 2024;104:409-423. doi: 10.1007/978-3-031-58843-3_15. PMID:38963494[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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