Factor Xa

Factor Xa, a trypsin-like serine protease, is situated at the critical juncture between the intrinsic and extrinsic pathways, catalyzing the conversion of prothrombin to thrombin, and hence plays a pivotal role in the final common pathway of the cascade and has become an important target in the discovery and development of new anticoagulants. Factor Xa is a key protease of the coagulation pathway whose activity is known to be in part modulated by binding to factor Va and sodium ions.

Blood coagulation involves a complex cascade of enzymatic reactions, ultimately generating fibrin, the basis of all blood clots. This cascade is comprised of two arms, the intrinsic and extrinsic pathways which converge at factor Xa to form the common pathway. Factor Xa activates prothrombin to thrombin, which in turn catalyzes the conversion of fibrinogen to fibrin.