Stuart factor, Coagulation factor X, F10, Stuart-Prower Factor, Prothrombinase, EC, Factor Xa, Factor X, FXA, FX, EC 3.4.21, EC:


Factor X, also known by the eponym Stuart–Prower factor, is an enzyme of the coagulation cascade. It is a serine endopeptidase (protease group S1, PA clan). Factor X is synthesized in the liver and requires vitamin K for its synthesis.Factor X is activated, by hydrolysis, into factor Xa by both factor IX (with its cofactor, factor VIII in a complex known as intrinsic Tenase) and factor VII with its cofactor, tissue factor (a complex known as extrinsic Tenase ). It is therefore the first member of the final common pathway or thrombin pathway.It acts by cleaving prothrombin in two places (an arg-thr and then an arg-ile bond), which yields the active thrombin. This process is optimized when factor Xa is complexed with activated co-factor V in the prothrombinase complex.Factor Xa is inactivated by protein Z-dependent protease inhibitor (ZPI), a serine protease inhibitor (serpin). The affinity of this protein for factor Xa is increased 1000-fold by the presence of protein Z, while it does not require protein Z for inactivation of factor XI. Defects in protein Z lead to increased factor Xa activity and a propensity for thrombosis.

KO Status


Drug Information

Launched drugs: 86
Drugs in clinical trials: 34
Latest Research Phase: Approved

Drug Name





Clinical Trials

Edoxaban Tosilate Hydrate



Daiichi Sankyo Co Ltd

Pulmonary Embolism, Embolism, Venous Thromboembolism, Neoplasms, Heart Diseases, Stroke, Thromboembolism, Embolism and Thrombosis, Atrial Fibrillation, Venous Thrombosis, Thrombosis

Heparin sodium biosimilar (Blau Pharmaceuticals)


Blau Pharmaceuticals


Nonacog gamma

rFIX, BAX-326



Hemophilia B

Rurioctocog alfa pegol

BAX-855, BAX-0855



Hemophilia A

Human prothrombin complex concentrate (Shanxi Kangbao Biological Products)


Shanxi Kangbao Biological Product Co Ltd


Antihemophilic factor B (Armour)


Csl Behring Llc, Armour Pharma

Hemophilia B

Prothrombinex-VF (CSL Behring)


Csl Behring Llc


Trenonacog alfa

IB-1001, APVO-101


Inspiration Biopharmaceuticals

Hemophilia B

Antithrombin III (Human, Grifols)


Grifols Sa

Antithrombin III Deficiency, Thromboembolism


MK-4448, PRT-021, MLN-1021, PRT-054021


Millennium Pharmaceuticals Inc

Venous Thromboembolism, Kidney Diseases, Thromboembolism, Atrial Fibrillation, Hepatic Insufficiency





Cloning and expression in COS-1 cells of a full-length cDNA encoding human coagulation factor X

Messier T.L., Pittman D.D., Long G.L., Kaufman R.J., Church W.R.,

Gene 99:291-294(1991)

Gene for human factor X: a blood coagulation factor whose gene organization is essentially identical with that of factor IX and protein C

Leytus S.P., Foster D.C., Kurachi K., Davie E.W.,

Biochemistry 25:5098-5102(1986)

The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)

The MGC Project Team,

Genome Res. 14:2121-2127(2004)

Complete amino acid sequence of the light chain of human blood coagulation factor X: evidence for identification of residue 63 as beta-hydroxyaspartic acid

McMullen B.A., Fujikawa K., Kisiel W., Sasagawa T., Howald W.N., Kwa E.Y., Weinstein B.,

Biochemistry 22:2875-2884(1983)

Characterization of a cDNA coding for human factor X

Leytus S.P., Chung D.W., Kisiel W., Kurachi K., Davie E.W.,

Proc. Natl. Acad. Sci. U.S.A. 81:3699-3702(1984)

Identification of O-linked oligosaccharide chains in the activation peptides of blood coagulation factor X. The role of the carbohydrate moieties in the activation of factor X

Inoue K., Morita T.,

Eur. J. Biochem. 218:153-163(1993)

Cloning and characterization of the 5' end (exon 1) of the gene encoding human factor X

Jagadeeswaran P., Reddy S.V., Rao K.J., Hamsabhushanam K., Lyman G.,

Gene 84:517-519(1989)

Mechanism of inhibition of activated protein C by protein C inhibitor

Suzuki K., Nishioka J., Kusumoto H., Hashimoto S.,

J. Biochem. 95:187-195(1984)

Basis for the specificity and activation of the serpin protein Z-dependent proteinase inhibitor (ZPI) as an inhibitor of membrane-associated factor Xa

Huang X., Dementiev A., Olson S.T., Gettins P.G.,

J. Biol. Chem. 285:20399-20409(2010)

Human urinary glycoproteomics; attachment site specific analysis of N- and O-linked glycosylations by CID and ECD

Halim A., Nilsson J., Ruetschi U., Hesse C., Larson G.,

Mol. Cell. Proteomics 11:1-17(2012)