Vitamin K epoxide reductase
Also known as: VKORC1
Enzyme that regenerates reduced vitamin K, required for activation (gamma-carboxylation) of clotting factors II, VII, IX and X and proteins C and S. It is the therapeutic target of coumarin anticoagulants.
Warfarin and acenocoumarol inhibit VKORC1, reducing synthesis of vitamin K-dependent factors; dietary vitamin K intake antagonises this effect and shifts the INR.
Substrates: vitamin K epoxide (regeneration of vitamin K).
Inhibitors: warfarin, acenocoumarol.
Inducers: not applicable.
VKORC1 polymorphism explains individual sensitivity to coumarins; stable vitamin K intake is essential to keep INR in range.
DailyMed/FDA (NIH/NLM) — approved Warfarin label; PubMed (NIH/NLM)
