Cholestanetriol 26-monooxygenase

cholestanetriol 26-monooxygenase
Identifiers
EC no.	1.14.13.15
CAS no.	52227-77-7
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
Search PMC articles PubMed articles NCBI proteins

In enzymology, a cholestanetriol 26-monooxygenase (EC 1.14.13.15) is an enzyme that catalyzes the chemical reaction

5beta-cholestane-3alpha,7alpha,12alpha-triol + NADPH + H⁺ + O₂ $\rightleftharpoons$ (25R)-5beta-cholestane-3alpha,7alpha,12alpha,26-tetraol + NADP⁺ + H₂O

The 4 substrates of this enzyme are 5beta-cholestane-3alpha,7alpha,12alpha-triol, NADPH, H⁺, and O₂, whereas its 3 products are (25R)-5beta-cholestane-3alpha,7alpha,12alpha,26-tetraol, NADP⁺, and H₂O.

This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with NADH or NADPH as one donor, and incorporation of one atom o oxygen into the other donor. The systematic name of this enzyme class is 5beta-cholestane-3alpha,7alpha,12alpha-triol,NADPH:oxygen oxidoreductase (26-hydroxylating). Other names in common use include 5beta-cholestane-3alpha,7alpha,12alpha-triol 26-hydroxylase, 5beta-cholestane-3alpha,7alpha,12alpha-triol hydroxylase, cholestanetriol 26-hydroxylase, sterol 27-hydroxylase, sterol 26-hydroxylase, cholesterol 27-hydroxylase, CYP27A, CYP27A1, and cytochrome P450 27A1'. This enzyme participates in bile acid biosynthesis and ppar signaling pathway.

References

• Okuda K, Hoshita N (1968). "Oxidation of 5-beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol by rat-liver mitochondria". Biochim. Biophys. Acta. 164 (2): 381–8. doi:10.1016/0005-2760(68)90162-8. PMID 4388637.
• Wikvall K (1984). "Hydroxylations in biosynthesis of bile acids. Isolation of a cytochrome P-450 from rabbit liver mitochondria catalyzing 26-hydroxylation of C27-steroids". J. Biol. Chem. 259 (6): 3800–4. PMID 6423637.
• Andersson S, Davis DL, Dahlback H, Jornvall H, Russell DW (1989). "Cloning, structure, and expression of the mitochondrial cytochrome P-450 sterol 26-hydroxylase, a bile acid biosynthetic enzyme". J. Biol. Chem. 264 (14): 8222–9. PMID 2722778.
• Usui E, Noshiro M, Okuda K (1990). "Molecular cloning of cDNA for vitamin D3 25-hydroxylase from rat liver mitochondria". FEBS Lett. 262 (1): 135–8. doi:10.1016/0014-5793(90)80172-F. PMID 2318307.
• Furster C, Bergman T, Wikvall K (1999). "Biochemical characterization of a truncated form of CYP27A purified from rabbit liver mitochondria". Biochem. Biophys. Res. Commun. 263 (3): 663–6. doi:10.1006/bbrc.1999.1426. PMID 10512735.
• Holmberg-Betsholtz I, Lund E, Bjorkhem I, Wikvall K (1993). "Sterol 27-hydroxylase in bile acid biosynthesis. Mechanism of oxidation of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,27-tetrol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid". J. Biol. Chem. 268 (15): 11079–85. PMID 8496170.
• Pikuleva IA, Puchkaev A, Bjorkhem I (2001). "Putative helix F contributes to regioselectivity of hydroxylation in mitochondrial cytochrome P450 27A1". Biochemistry. 40 (25): 7621–9. doi:10.1021/bi010193i. PMID 11412116.