Vitamin K epoxide reductase (warfarin sensitive)

In enzymology, a vitamin-K-epoxide reductase (warfarin-sensitive) (EC 1.1.4.1) is an enzyme that catalyzes the chemical reaction

2-methyl-3-phytyl-1,4-naphthoquinone + oxidized dithiothreitol ⇌ 2,3-epoxy-2,3-dihydro-2-methyl-3-phytyl-1,4-naphthoquinone + 1,4-dithiothreitol

Thus, the two substrates of this enzyme are 2-methyl-3-phytyl-1,4-naphthoquinone and oxidized dithiothreitol, whereas its two products are 2,3-epoxy-2,3-dihydro-2-methyl-3-phytyl-1,4-naphthoquinone and 1,4-dithiothreitol.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with a disulfide as acceptor. The systematic name of this enzyme class is 2-methyl-3-phytyl-1,4-naphthoquinone:oxidized-dithiothreitol oxidoreductase. This enzyme participates in biosynthesis of steroids. At least one compound, Warfarin is known to inhibit this enzyme.