|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 18.104.22.1680
Enzymes and Genes:
retinol dehydrogenase 12 : RDH12 ( Homo sapiens )
retinol dehydrogenase 9 : DHRS9 ( Homo sapiens )
retinol dehydrogenase 11 : RDH11 ( Homo sapiens )
retinol dehydrogenase 3 : DHRS3 ( Homo sapiens )
retinol dehydrogenase 10 : RDH10 ( Homo sapiens )
retinol dehydrogenase 8 : RDH8 ( Homo sapiens )
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: NADP-retinol dehydrogenase
Enzyme Commission Synonyms: all-trans retinal reductase (ambiguous), all-trans-retinol dehydrogenase, NADP(H)-dependent retinol dehydrogenase/reductase, RDH11, RDH12, RDH13, RDH14, retinol dehydrogenase 12, retinol dehydrogenase 14, retinol dehydrogenase [NADP+], RalR1, PSDR1
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): -0.25645447 [Latendresse13]
Enzyme Commission Summary:
Greater catalytic efficiency in the reductive, rather than in the oxidative, direction and localization at the entrance to the mitochondrial matrix suggests that this enzyme may function to protect mitochondria against oxidative stress associated with the highly reactive all-trans-retinal produced from dietary all-trans-β-carotene by EC 22.214.171.124 [Belyaeva08]. Km-values for NADP+ and NADPH are at least 800-fold lower than those for NAD+ and NADH [Kedishvili02, Belyaeva05]. This enzyme differs from EC 126.96.36.199, retinol dehydrogenase, which prefers NAD+ and NADH.
Instance reactions of [allopregnanolone + NAD(P)+ ↔ 5-α-pregnane-3,20-dione + NAD(P)H + H+] (188.8.131.52):
i1: allopregnanolone + NAD+ → 5-α-pregnane-3,20-dione + NADH + H+ (1.1.-.-)
i2: allopregnanolone + NADP+ ← 5-α-pregnane-3,20-dione + NADPH + H+ (184.108.40.2068)
Instance reactions of [testosterone + NAD(P)+ → androst-4-ene-3,17-dione + NAD(P)H + H+] (220.127.116.11):
i3: testosterone + NAD+ = androst-4-ene-3,17-dione + NADH + H+ (18.104.22.168)
i4: testosterone + NADP+ ← androst-4-ene-3,17-dione + NADPH + H+ (22.214.171.124)
Belyaeva05: Belyaeva OV, Korkina OV, Stetsenko AV, Kim T, Nelson PS, Kedishvili NY (2005). "Biochemical properties of purified human retinol dehydrogenase 12 (RDH12): catalytic efficiency toward retinoids and C9 aldehydes and effects of cellular retinol-binding protein type I (CRBPI) and cellular retinaldehyde-binding protein (CRALBP) on the oxidation and reduction of retinoids." Biochemistry 44(18);7035-47. PMID: 15865448
Belyaeva08: Belyaeva OV, Korkina OV, Stetsenko AV, Kedishvili NY (2008). "Human retinol dehydrogenase 13 (RDH13) is a mitochondrial short-chain dehydrogenase/reductase with a retinaldehyde reductase activity." FEBS J 275(1);138-47. PMID: 18039331
Haeseleer98: Haeseleer F, Huang J, Lebioda L, Saari JC, Palczewski K (1998). "Molecular characterization of a novel short-chain dehydrogenase/reductase that reduces all-trans-retinal." J Biol Chem 273(34);21790-9. PMID: 9705317
Kedishvili02: Kedishvili NY, Chumakova OV, Chetyrkin SV, Belyaeva OV, Lapshina EA, Lin DW, Matsumura M, Nelson PS (2002). "Evidence that the human gene for prostate short-chain dehydrogenase/reductase (PSDR1) encodes a novel retinal reductase (RalR1)." J Biol Chem 277(32);28909-15. PMID: 12036956
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