IUBMB Enzyme Nomenclature


Accepted name: 12α-hydroxysteroid dehydrogenase

Reaction: cholate + NADP+ = 3α,7α-dihydroxy-12-oxo-5β-cholanate + NADPH + H+

Glossary: cholate = 3α,7α,12α-trihydroxy-5β-cholanate

Other name(s): 12α-hydroxy steroid dehydrogenase; 12α-hydroxy steroid dehydrogenase; NAD-dependent 12α-hydroxysteroid dehydrogenase; NADP-12α-hydroxysteroid dehydrogenase

Systematic name: 12α-hydroxysteroid:NADP+ 12-oxidoreductase

Comments: Catalyses the oxidation of the 12α-hydroxy group of bile acids, both in their free and conjugated form. Also acts on bile alcohols.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 61642-40-8


1. Macdonald, I.A., Mahony, D.E., Jellett, J.F. and Meier, C.E. NAD-dependent 3α- and 12α-hydroxysteroid dehydrogenase activities from Eubacterium lentum ATCC no. 25559. Biochim. Biophys. Acta 489 (1977) 466-476. [PMID: 201289]

2. Mahony, D.E., Meier, C.E., Macdonald, I.A. and Holdeman, L.V. Bile salt degradation by nonfermentative clostridia. Appl. Environ. Microbiol. 34 (1977) 419-423. [PMID: 921266]

[EC created 1978]

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