Biology:Cholesterol oxidase

From HandWiki
Cholesterol oxidase substrate-binding domain
crystal structure of cholesterol oxidase from b.sterolicum
Identifiers
SymbolChol_subst-bind
PfamPF09129
Pfam clanCL0277
InterProIPR015213
SCOP21i19 / SCOPe / SUPFAM

In enzymology, cholesterol oxidase (EC 1.1.3.6) is an enzyme that catalyzes the chemical reaction

Template:Chemrxn

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 1B4V, 1B8S, 1CBO, 1CC2, 1COY, 1I19, 1IJH, 1MXT, 1N1P, 1N4U, 1N4V, 1N4W, 2GEW, and 3COX.

References

  1. Enzyme 1.1.3.6 at KEGG Pathway Database.
  2. 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. 
  3. "Studies on the microbiological degradation of cholesterol". J. Biol. Chem. 206 (2): 511–23. 1954. doi:10.1016/S0021-9258(19)50819-5. PMID 13143010. 
  4. "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. August 2001. doi:10.1074/jbc.M104103200. PMID 11397813. 
This article incorporates text from the public domain Pfam and InterPro: IPR015213