Accepted name: cholesterol oxidase
Reaction: cholesterol + O2 = cholest-5-en-3-one + H2O2
Other name(s): cholesterol- O2 oxidoreductase; 3β-hydroxy steroid oxidoreductase; 3β-hydroxysteroid:oxygen oxidoreductase
Systematic name: cholesterol:oxygen oxidoreductase
Comments: Contains 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).
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]