IUBMB Enzyme Nomenclature


Accepted name: cholesterol oxidase

Reaction: cholesterol + O2 = cholest-5-en-3-one + H2O2

For diagram of reaction click here

Other name(s): cholesterol- O2 oxidoreductase; 3β-hydroxy steroid oxidoreductase; 3β-hydroxysteroid:oxygen oxidoreductase

Systematic name: cholesterol:oxygen oxidoreductase

Comments: Contains flavin adenine dinucleotide (FAD). Cholesterol oxidases are secreted bacterial bifunctional enzymes that catalyse the first two steps in the degradation of cholesterol. The enzyme catalyses the oxidation of the 3β-hydroxyl group to a keto group, and the isomerization of the double bond in the oxidized steroid ring system from the Δ5 position to Δ6 position (cf. EC, steroid Δ-isomerase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9028-76-6


1. Richmond, W. Preparation and properties of a cholesterol oxidase from Nocardia sp. and its application to the enzymatic assay of total cholesterol in serum. Clin. Chem. 19 (1973) 1350-1356. [PMID: 4757363]

2. Stadtman, T.C., Cherkes, A. and Anfinsen, C.B. Studies on the microbiological degradation of cholesterol. J. Biol. Chem. 206 (1954) 511-523. [PMID: 13143010]

3. MacLachlan, J., Wotherspoon, A.T., Ansell, R.O. and Brooks, C.J. Cholesterol oxidase: sources, physical properties and analytical applications. J. Steroid Biochem. Mol. Biol. 72 (2000) 169-195. [PMID: 10822008]

4. Vrielink, A. Cholesterol oxidase: structure and function. Subcell. Biochem. 51 (2010) 137-158. [PMID: 20213543]

[EC created 1961, modified 1982, modified 2012]

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