A liver microsomal cytochrome P450 enzyme that catalyzes the 12-alpha-hydroxylation of a broad spectrum of sterols in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP8B1gene, converts 7-alpha-hydroxy-4-cholesten-3-one to 7-alpha-12-alpha-dihydroxy-4-cholesten-3-one and is required in the synthesis of BILE ACIDS from cholesterol.

Synonyms: 12 alpha Hydroxylase, Sterol 12-alpha-Hydroxylase, Steroid 12-alpha-Hydroxylase, 12alpha Hydroxylase, Steroid 12 Monooxygenase, Steroid 12-Monooxygenase, Steroid 12 Hydroxylase, 12 alpha-Hydroxylase, Sterol, Steroid 12 alpha Hydroxylase, Steroid 12-Hydroxylase, CYP8B1, Sterol 12 alpha Hydroxylase, Steroid, hydrogen-donor:oxygen oxidoreductase (12-alpha-hydroxylating), alpha-Hydroxylase, Sterol 12, 12alpha-Hydroxylase, Cytochrome P450 CYP8B1, Steroid-12-Monooxygenase, Sterol 12 alpha-Hydroxylase, EC 1.14.18.8, Steroid-12-Hydroxylase, Cytochrome P450 8B1, 12-alpha-Hydroxylase