| cholesterol oxidase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.1.3.6 | ||||||||
| CAS no. | 9028-76-6 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
| Cholesterol oxidase substrate-binding domain | |||||||
|---|---|---|---|---|---|---|---|
 crystal structure of cholesterol oxidase from b.sterolicum | |||||||
| Identifiers | |||||||
| Symbol | Chol_subst-bind | ||||||
| Pfam | PF09129 | ||||||
| Pfam clan | CL0277 | ||||||
| InterPro | IPR015213 | ||||||
| SCOP2 | 1i19 / SCOPe / SUPFAM | ||||||
| |||||||
In enzymology, cholesterol oxidase (EC 1.1.3.6) is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are cholesterol and oxygen. Its products are cholest-4-en-3-one (cholesterone) and hydrogen peroxide.[1][2][3]
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with oxygen as acceptor. The systematic name of this enzyme class is cholesterol:oxygen oxidoreductase. Other names in common use include cholesterol- O2 oxidoreductase, 3beta-hydroxy steroid oxidoreductase, and 3beta-hydroxysteroid:oxygen oxidoreductase. This enzyme participates in bile acid biosynthesis.
The substrate-binding domain found in some bacterial cholesterol oxidases is composed of an eight-stranded mixed beta-pleated sheet and six alpha-helices. This domain is positioned over the isoalloxazine ring system of the FAD cofactor bound by the FAD-binding domain and forms the roof of the active site cavity, allowing for catalysis of oxidation and isomerisation of cholesterol to cholest-4-en-3-one.[4]
Structural studies
As of late 2007, 14 structures have been solved for this class of enzymes, with PDB accession codes PDB: 1B4V, PDB: 1B8S, PDB: 1CBO, PDB: 1CC2, PDB: 1COY, PDB: 1I19, PDB: 1IJH, PDB: 1MXT, PDB: 1N1P, PDB: 1N4U, PDB: 1N4V, PDB: 1N4W, PDB: 2GEW, and PDB: 3COX.
References
- Enzyme 1.1.3.6 at KEGG Pathway Database.
- Richmond W (1973). "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 (12): 1350–6. doi:10.1093/clinchem/19.12.1350. PMID 4757363.
- Stadtman TC, Cherkes A, Anfinsen CB (1954). "Studies on the microbiological degradation of cholesterol". J. Biol. Chem. 206 (2): 511–23. doi:10.1016/S0021-9258(19)50819-5. PMID 13143010.
- Coulombe R, Yue KQ, Ghisla S, Vrielink A (August 2001). "Oxygen access to the active site of cholesterol oxidase through a narrow channel is gated by an Arg-Glu pair". J. Biol. Chem. 276 (32): 30435–41. doi:10.1074/jbc.M104103200. PMID 11397813.