IUBMB Enzyme Nomenclature


Accepted name: cholesterol 7α-monooxygenase

Reaction: cholesterol + [reduced NADPH—hemoprotein reductase] + O2 = 7α-hydroxycholesterol + [oxidized NADPH—hemoprotein reductase] + H2O

For diagram of reaction click here.

Other name(s): cholesterol 7α-hydroxylase; CYP7A1 (gene name)

Systematic name: cholesterol,NADPH—hemoprotein reductase:oxygen oxidoreductase (7α-hydroxylating)

Comments: A P-450 heme-thiolate liver protein that catalyses the first step in the biosynthesis of bile acids. The direct electron donor to the enzyme is EC, NADPH—hemoprotein reductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Mitton, J.R., Scholan, N.A. and Boyd, G.S. The oxidation of cholesterol in rat liver sub-cellular particles. The cholesterol-7α-hydroxylase enzyme system. Eur. J. Biochem. 20 (1971) 569-579. [PMID: 4397276]

2. Boyd, G.S., Grimwade, A.M. and Lawson, M.E. Studies on rat-liver microsomal cholesterol 7α-hydroxylase. Eur. J. Biochem. 37 (1973) 334-340. [PMID: 4147676]

3. Ogishima, T., Deguchi, S. and Okuda, K. Purification and characterization of cholesterol 7α-hydroxylase from rat liver microsomes. J. Biol. Chem. 262 (1987) 7646-7650. [PMID: 3584134]

4. Nguyen, L.B., Shefer, S., Salen, G., Ness, G., Tanaka, R.D., Packin, V., Thomas, P., Shore, V. and Batta, A. Purification of cholesterol 7 α-hydroxylase from human and rat liver and production of inhibiting polyclonal antibodies. J. Biol. Chem. 265 (1990) 4541-4546. [PMID: 2106520]

5. Nguyen, L.B., Shefer, S., Salen, G., Chiang, J.Y. and Patel, M. Cholesterol 7α-hydroxylase activities from human and rat liver are modulated in vitro posttranslationally by phosphorylation/dephosphorylation. Hepatology 24 (1996) 1468-1474. [PMID: 8938182]

[EC created 1976 as EC, transferred 2016 to EC]

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