3alpha,7alpha,12alpha-trihydroxycholestan-26-al 26-oxidoreductase

3-alpha,7-alpha,12-alpha-trihydroxycholestan-26-al 26-oxidoreductase
Identifiers
EC number	1.2.1.40
CAS number	62213-58-5
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 / EGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a 3alpha,7alpha,12alpha-trihydroxycholestan-26-al 26-oxidoreductase is an enzyme that catalyzes the chemical reaction:^[1]

(25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-al + NAD⁺ + H₂O $\rightleftharpoons$ (25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-oate + NADH + 2 H⁺

The 3 substrates of this enzyme are (25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-al, NAD⁺, and H₂O, whereas its 2 products are (25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-oate, NADH, and H⁺. This enzyme participates in bile acid biosynthesis.

Nomenclature

This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-al:NAD+ 26-oxidoreductase. Other names in common use include:

• cholestanetriol-26-al 26-dehydrogenase,
• 3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-al, dehydrogenase,
• trihydroxydeoxycoprostanal dehydrogenase,
• THAL-NAD oxidoreductase,
• 3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-al:NAD+, and
• 26-oxidoreductase.

References

1. Masui T, Herman R, Staple E (March 1966). "The oxidation of 5-beta-cholestane-3-alpha, 7-alpha, 12-alpha, 26-tetraol to 5-beta-cholestane-3-alpha, 7-alpha, 12-alpha-triol-26-oic acid via 5-beta-cholestane-3-alpha, 7-alpha, 12-alpha-triol-26-al by rat liver". Biochim. Biophys. Acta 117 (1): 266–8. doi:10.1016/0304-4165(66)90177-2. PMID 5914340.