Factor X

Factor X is a protein that plays a key role in the blood clotting process. It is part of the coagulation cascade, a series of reactions that ultimately leads to the formation of a blood clot. Factor X is activated by either Factor IX (in the intrinsic pathway) or Factor VII (in the extrinsic pathway). Once activated, Factor X converts prothrombin into thrombin, which then converts fibrinogen into fibrin, the main substance of a clot.

Structure

Factor X is a single-chain serine protease (enzyme) that is synthesized in the liver. It is a vitamin K-dependent protein, meaning it requires vitamin K for its synthesis.

Function

The primary function of Factor X is to initiate the final common pathway of the coagulation cascade. It does this by converting prothrombin into thrombin in a reaction that is greatly accelerated by Factor V. The thrombin then converts soluble fibrinogen into insoluble fibrin, which aggregates to form a blood clot.

Clinical significance

Deficiency of Factor X is a rare condition that can lead to increased bleeding. This can be due to a genetic disorder known as Factor X deficiency, or it can be acquired as a result of liver disease, vitamin K deficiency, or use of certain medications such as warfarin.

See also

• Coagulation
• Factor IX
• Factor VII
• Prothrombin
• Thrombin
• Fibrinogen
• Fibrin
• Factor X deficiency
• Liver disease
• Vitamin K deficiency
• Warfarin

Factor X Resources
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