Enzymes
| UniProtKB help_outline | 4 proteins |
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- Name help_outline (3β,5α,17β)-3-hydroxyandrostan-17-yl sulfate Identifier CHEBI:136983 Charge -1 Formula C19H31O5S InChIKeyhelp_outline KWYNDVHEQWYGIL-YSZCXEEOSA-M SMILEShelp_outline [C@@H]1(OS([O-])(=O)=O)[C@]2(CC[C@]3([C@]([C@@]2(CC1)[H])(CC[C@@]4([C@@]3(CC[C@@H](C4)O)C)[H])[H])[H])C 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADP+ Identifier CHEBI:58349 Charge -3 Formula C21H25N7O17P3 InChIKeyhelp_outline XJLXINKUBYWONI-NNYOXOHSSA-K SMILEShelp_outline NC(=O)c1ccc[n+](c1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,253 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 5α-dihydrotestosterone sulfate Identifier CHEBI:136982 Charge -1 Formula C19H29O5S InChIKeyhelp_outline KYVPWJSGFKNNLD-ABEVXSGRSA-M SMILEShelp_outline [C@@H]1(OS([O-])(=O)=O)[C@]2(CC[C@]3([C@]([C@@]2(CC1)[H])(CC[C@@]4([C@@]3(CCC(C4)=O)C)[H])[H])[H])C 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADPH Identifier CHEBI:57783 (Beilstein: 10411862) help_outline Charge -4 Formula C21H26N7O17P3 InChIKeyhelp_outline ACFIXJIJDZMPPO-NNYOXOHSSA-J SMILEShelp_outline NC(=O)C1=CN(C=CC1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,247 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:53120 | RHEA:53121 | RHEA:53122 | RHEA:53123 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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Human cytosolic hydroxysteroid dehydrogenases of the aldo-ketoreductase superfamily catalyze reduction of conjugated steroids: implications for phase I and phase II steroid hormone metabolism.
Jin Y., Duan L., Lee S.H., Kloosterboer H.J., Blair I.A., Penning T.M.
Aldo-ketoreductase 1C (AKR1C) enzymes catalyze the NADPH-dependent reduction of ketosteroids to hydroxysteroids. They are Phase I metabolizing enzymes for natural and synthetic steroid hormones. They convert 5alpha-dihydrotestosterone (Dht, potent androgen) to 3alpha/beta-androstanediols (inactive ... >> More
Aldo-ketoreductase 1C (AKR1C) enzymes catalyze the NADPH-dependent reduction of ketosteroids to hydroxysteroids. They are Phase I metabolizing enzymes for natural and synthetic steroid hormones. They convert 5alpha-dihydrotestosterone (Dht, potent androgen) to 3alpha/beta-androstanediols (inactive androgens) and the prodrug tibolone (Tib) to estrogenic 3alpha/beta-hydroxytibolones. Herein we demonstrate for the first time that human AKR1C enzymes (AKR1C1-4) are able to reduce conjugated steroids such as Dht-17beta-glucuronide (DhtG), Dht-17beta-sulfate (DhtS), and Tib-17beta-sulfate (TibS). Product identities were characterized by liquid chromatography-mass spectrometry, and kinetic parameters of the reactions were determined. The product profile of the reduction of each steroid conjugate by the individual AKR1C isoform was similar to that of the corresponding free steroid except for the reduction of DhtG catalyzed by AKR1C2, where a complete inversion in stereochemical preference to 3beta-reduction (with DhtG) from 3alpha-reduction (with Dht and DhtS) was observed. The catalytic efficiency of 3-keto reduction was modestly affected by the presence of a 17-sulfate group but severely impaired by the presence of a 17-glucuronide group for AKR1C1-3 isoforms. AKR1C4, however, showed superior catalytic efficiencies versus the other isoforms, and those were unaffected by steroid conjugation. Our findings provide evidence for alternative pathways of steroid metabolism where the phase I reaction (reduction) occurs after the phase II reaction (conjugation). Specifically, it is indicated that Dht is metabolized to its metabolite 3alpha-androstanediol-17-glucuronide via the previously unrecognized "conjugation pathway" involving the sequential reactions of UGT2B17 and AKR1C4 in liver but via the conventional "reduction pathway" involving the sequential reactions of AKR1C2 and UGT2B15/17 in prostate. << Less
J. Biol. Chem. 284:10013-10022(2009) [PubMed] [EuropePMC]
This publication is cited by 4 other entries.