vitamin-K-epoxide reductase (warfarin-sensitive) activity
Definition
Target type: molecularfunction
Catalysis of the reaction: phylloquinol + a protein with a disulfide bond = phylloquinone + a protein with reduced L-cysteine residues. [RHEA:57744]
Vitamin-K-epoxide reductase (warfarin-sensitive) activity, also known as VKORC1, is an enzyme that plays a crucial role in the coagulation cascade by catalyzing the reduction of vitamin K epoxide to its active hydroquinone form. This enzyme is essential for the synthesis of functional coagulation factors II, VII, IX, and X, as well as protein C and protein S. These factors are involved in the formation of a fibrin clot, which is necessary for blood clotting.
The enzyme utilizes vitamin K hydroquinone as a cofactor, which is oxidized to vitamin K epoxide during the carboxylation of the coagulation factors. VKORC1 then reduces vitamin K epoxide back to its active hydroquinone form, enabling the continuation of the coagulation cascade.
The enzyme is highly specific for vitamin K epoxide, and its activity is inhibited by warfarin, a commonly prescribed anticoagulant. Warfarin inhibits VKORC1 by competitively binding to the enzyme's active site, preventing the reduction of vitamin K epoxide. This inhibition leads to a decrease in the synthesis of functional coagulation factors, resulting in a prolonged clotting time and reduced risk of thrombosis.
VKORC1 is a crucial enzyme in the coagulation cascade, and its activity is tightly regulated. The enzyme's function is essential for proper blood clotting, and its inhibition by warfarin provides a therapeutic target for the treatment of thromboembolic disorders.'
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Proteins (4)
| Protein | Definition | Taxonomy |
|---|---|---|
| Vitamin K epoxide reductase complex subunit 1 | [no definition available] | Bos taurus (cattle) |
| Vitamin K epoxide reductase complex subunit 1-like protein 1 | A vitamin K epoxide reductase complex subunit 1-like protein 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8N0U8] | Homo sapiens (human) |
| Vitamin K epoxide reductase complex subunit 1 | A vitamin K epoxide reductase complex subunit 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9BQB6] | Homo sapiens (human) |
| Vitamin K epoxide reductase complex subunit 1-like protein 1 | A vitamin K epoxide reductase complex subunit 1-like protein 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8N0U8] | Homo sapiens (human) |
Compounds (2)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| vitamin k1 oxide | vitamin K1 oxide: RN given refers to parent cpd; see also record for 2,3-epoxymenaquinone | ||
| warfarin | 4-hydroxy-3-(3-oxo-1-phenylbutyl)-1-benzopyran-2-one : A member of the class of coumarins that is 4-hydroxycoumarin which is substituted at position 3 by a 1-phenyl-3-oxo-1-butyl group. warfarin : A racemate comprising equal amounts of (R)- and (S)-warfarin. Extensively used as both an anticoagulant drug and as a pesticide against rats and mice. Warfarin: An anticoagulant that acts by inhibiting the synthesis of vitamin K-dependent coagulation factors. Warfarin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, pulmonary embolism, and atrial fibrillation with embolization. It is also used as an adjunct in the prophylaxis of systemic embolism after myocardial infarction. Warfarin is also used as a rodenticide. | benzenes; hydroxycoumarin; methyl ketone |