7alpha-hydroxycholest-4-en-3-one 12alpha-hydroxylase

In enzymology, a 7alpha-hydroxycholest-4-en-3-one 12alpha-hydroxylase () is an enzyme that catalyzes the chemical reaction
The 4 substrates of this enzyme are 7alpha-hydroxycholest-4-en-3-one (7 alpha-hydroxy-4-cholesten-3-one, NADPH, H+, and O2, whereas its 3 products are 7alpha,12alpha-dihydroxycholest-4-en-3-one, NADP+, and H2O.
This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with NADH or NADPH as one donor, and incorporation of one atom o oxygen into the other donor. The systematic name of this enzyme class is 7alpha-hydroxycholest-4-en-3-one,NADPH:oxygen oxidoreductase (12alpha-hydroxylating).
This enzymatic activity is performed by CYP8B1.
Other names used include 7alpha-hydroxy-4-cholesten-3-one 12alpha-monooxygenase, CYP12, sterol 12alpha-hydroxylase (ambiguous), and HCO 12alpha-hydroxylase. This enzyme participates in ppar signaling pathway.