Lathosterol oxidase

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In enzymology, a lathosterol oxidase (EC 1.14.21.6) is an enzyme that catalyzes the chemical reaction

5alpha-cholest-7-en-3beta-ol + NAD(P)H + H⁺ + O₂ $\rightleftharpoons$ cholesta-5,7-dien-3beta-ol + NAD(P)+ + 2 H₂O

The 5 substrates of this enzyme are 5alpha-cholest-7-en-3beta-ol, NADH, NADPH, H⁺, and O₂, whereas its 4 products are cholesta-5,7-dien-3beta-ol, NAD⁺, 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 the other dehydrogenated. The systematic name of this enzyme class is 5alpha-cholest-7-en-3beta-ol,NAD(P)H:oxygen 5-oxidoreductase. Other names in common use include Delta7-sterol Delta5-dehydrogenase, Delta7-sterol 5-desaturase, Delta7-sterol-C5(6)-desaturase, and 5-DES. This enzyme participates in biosynthesis of steroids. It has 2 cofactors: FAD, and FMN.

[edit] References

IUBMB entry for 1.14.21.6
BRENDA references for 1.14.21.6 (Recommended.)
PubMed references for 1.14.21.6
PubMed Central references for 1.14.21.6
Google Scholar references for 1.14.21.6
DEMPSEY ME, SEATON JD, SCHROEPFER GJ Jr, TROCKMAN RW (1964). "THE INTERMEDIARY ROLE OF DELTA-5,7-CHOLESTADIEN-3-BETA-OL IN CHOLESTEROL BIOSYNTHESIS". J. Biol. Chem. 239: 1381–7. PMID 14189869.
Nishino H, Nakaya J, Nishi S, Kurosawa T, Ishibashi T (1997). "Temperature-induced differential kinetic properties between an initial burst and the following steady state in membrane-bound enzymes: studies on lathosterol 5-desaturase". Arch. Biochem. Biophys. 339: 298–304. doi:10.1006/abbi.1996.9871. PMID 9056262.
Taton M, Rahier A (1996). "Plant sterol biosynthesis: identification and characterization of higher plant delta 7-sterol C5(6)-desaturase". Arch. Biochem. Biophys. 325: 279–88. doi:10.1006/abbi.1996.0035. PMID 8561508.
Taton M, Husselstein T, Benveniste P, Rahier A (2000). "Role of highly conserved residues in the reaction catalyzed by recombinant Delta7-sterol-C5(6)-desaturase studied by site-directed mutagenesis". Biochemistry. 39: 701–11. doi:10.1021/bi991467t. PMID 10651635.