IUBMB Enzyme Nomenclature

EC 3.4.21.69

Accepted name: activated protein C (thrombin-activated peptidase)

Reaction: Degradation of blood coagulation factors Va and VIIIa

Other name(s): blood-coagulation factor XIVa; activated blood coagulation factor XIV; activated protein C; autoprothrombin II-A; protein Ca; APC; GSAPC; protein C (activated)

Comments: A peptidase of family S1 (trypsin family), one of the γ-carboxyglutamic acid-containing coagulation factors. The enzyme plays an important role in regulating anticoagulation, inflammation, and cell death by proteolytically inactivating the blood coagulation factors factor Va and factor VIIIa. Formed from protein C, the proenzyme that circulates in plasma, by the action of a complex of thrombin with thrombomodulin. Protein C can also be activated by serine endopeptidases present in several snake venoms.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, MEROPS, PDB, CAS registry number: 42617-41-4

References:

1. Esmon, C.T. The regulation of natural anticoagulant pathways. Science 235 (1987) 1348-1352. [PMID: 3029867]

2. Esmon, C.T. The roles of protein C and thrombomodulin in the regulation of blood coagulation. J. Biol. Chem. 264 (1989) 4743-4746. [PMID: 2538457]

[EC 3.4.21.69 created 1992, modified 2025]


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