Reaction: Cholesta-7,24-dien-3beta-ol is desaturated to form cholesta-5,7,24-trien-3beta-ol
- in pathway: Cholesterol biosynthesis via desmosterol
Cholesta-7,24-dien-3beta-ol, NADPH + H+, and O2 react to form cholesta-5,7,24-trien-3beta-ol, NADP+, and 2 H2O, catalyzed by SC5D. This reaction takes place in the endoplasmic reticulum. Its biochemical details are inferred from those of the reaction catalyzed by the purified rat protein (Kawata et al. 1985). The role of human SC5D in catalyzing this reaction in vivo is established from studies of patients in whom the enzyme is defective (Brunetti-Pierri et al. 2002; Krakowiak et al. 2003).
Reaction - small molecule participants:
H2O [cytosol]
NADP+ [cytosol]
7dhDESOL [endoplasmic reticulum membrane]
H+ [cytosol]
CHdOL [endoplasmic reticulum membrane]
O2 [cytosol]
NADPH [cytosol]
Reactome.org reaction link: R-HSA-195664
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Reaction input - small molecules:
hydron
5alpha-cholesta-7,24-dien-3beta-ol
dioxygen
NADPH(4-)
Reaction output - small molecules:
water
NADP(3-)
7-dehydrodesmosterol
Reactome.org link: R-HSA-195664