Enzymes
UniProtKB help_outline | 4 proteins |
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- Name help_outline 7α-hydroxycholest-4-en-3-one Identifier CHEBI:17899 (CAS: 3862-25-7) help_outline Charge 0 Formula C27H44O2 InChIKeyhelp_outline IOIZWEJGGCZDOL-RQDYSCIWSA-N SMILEShelp_outline [H][C@@]1(CC[C@@]2([H])[C@]3([H])[C@H](O)CC4=CC(=O)CC[C@]4(C)[C@@]3([H])CC[C@]12C)[C@H](C)CCCC(C)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 9,331 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 1,256 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 7α-hydroxy-5β-cholestan-3-one Identifier CHEBI:2290 (Beilstein: 3159830,2300476) help_outline Charge 0 Formula C27H46O2 InChIKeyhelp_outline HWOOALPDOJHOPO-YREUSXKVSA-N SMILEShelp_outline [H][C@]12C[C@@H](O)[C@]3([H])[C@]([H])(CC[C@]4(C)[C@]([H])(CC[C@@]34[H])[C@H](C)CCCC(C)C)[C@@]1(C)CCC(=O)C2 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 1,262 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:46640 | RHEA:46641 | RHEA:46642 | RHEA:46643 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Related reactions help_outline
More general form(s) of this reaction
Publications
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Cloning and expression of cDNA of human delta 4-3-oxosteroid 5 beta-reductase and substrate specificity of the expressed enzyme.
Kondo K.-H., Kai M.-H., Setoguchi Y., Eggertsen G., Sjoeblom P., Setoguchi T., Okuda K., Bjoerkhem I.
The enzyme delta 4-3-oxosteroid 5 beta-reductase (3-oxo-5 beta-steroid: NADP+ oxidoreductase and 4,5 beta-dihydrocortisone: NADP+ delta 4-oxidoreductase) catalyzes the reduction of the delta 4 double bond of bile acid intermediates and steroid hormones carrying the delta 4-3-one structure in the A ... >> More
The enzyme delta 4-3-oxosteroid 5 beta-reductase (3-oxo-5 beta-steroid: NADP+ oxidoreductase and 4,5 beta-dihydrocortisone: NADP+ delta 4-oxidoreductase) catalyzes the reduction of the delta 4 double bond of bile acid intermediates and steroid hormones carrying the delta 4-3-one structure in the A/B cis configuration. Human delta 4-3-oxosteroid 5 beta-reductase cDNA was isolated from a liver cDNA library by cross hybridization with a previously cloned rat cDNA, which was used as a probe [Onishi, Y. Noshiro, M., Shimosato, T. & Okuda, K.-I. (1991) FEBS Lett. 283, 215-218]. DNA sequence analysis of a hybridization-positive clone predicted the human delta 4-3-oxosteroid 5 beta-reductase to contain 326 amino acids. The amino acid sequence of the human delta 4-3-oxosteroid 5 beta-reductase had 79% overall identity to the rat enzyme sequence. It also showed 54% and 50% overall identity with rat 3 alpha-hydroxysteroid dehydrogenase and human aldose reductase, respectively. RNA blotting analysis demonstrated the existence of a single delta 4-3-oxosteroid 5 beta-reductase mRNA of approximately 2.7 kb in human liver. Transfection of the cDNA into COS cells resulted in the expression of an active enzyme with a high activity toward the bile acid intermediates 7 alpha,12 alpha-dihydroxy-4-cholesten-3-one and 7 alpha-hydroxy-4-cholesten-3-one. In addition, the expressed enzyme showed a small but significant 5 beta-reduction activity toward 11 beta,17 alpha,21-trihydroxy-delta 4-pregnene-3,20-dione (cortisol) and 17 beta-hydroxy-delta 4-androsten-3-one (testosterone) whereas no activity was observed toward delta 4-pregnene-3,20-dione (progesterone) or delta 4-androstene-3-17-dione (androstenedione). The substrate specificity of the human enzyme is considerably narrower than that of the rat enzyme, and the enzyme seems to be more important for bile acid biosynthesis than for metabolism of steroid hormones. << Less
Eur. J. Biochem. 219:357-363(1994) [PubMed] [EuropePMC]
This publication is cited by 5 other entries.
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Substrate specificity and inhibitor analyses of human steroid 5beta-reductase (AKR1D1).
Chen M., Drury J.E., Penning T.M.
Human steroid 5β-reductase (aldo-keto reductase 1D1) catalyzes the stereospecific NADPH-dependent reduction of the C4-C5 double bond of Δ(4)-ketosteroids to yield an A/B cis-ring junction. This cis-configuration is crucial for bile acid biosynthesis and plays important roles in steroid metabolism. ... >> More
Human steroid 5β-reductase (aldo-keto reductase 1D1) catalyzes the stereospecific NADPH-dependent reduction of the C4-C5 double bond of Δ(4)-ketosteroids to yield an A/B cis-ring junction. This cis-configuration is crucial for bile acid biosynthesis and plays important roles in steroid metabolism. The biochemical properties of the enzyme have not been thoroughly studied and conflicting data have been reported, partially due to the lack of highly homogeneous protein. In the present study, we systematically determined the substrate specificity of homogeneous human recombinant AKR1D1 using C18, C19, C21, and C27 Δ(4)-ketosteroids and assessed the pH-rate dependence of the enzyme. Our results show that AKR1D1 proficiently reduced all the steroids tested at physiological pH, indicating AKR1D1 is the only enzyme necessary for all the 5β-steroid metabolites present in humans. Substrate inhibition was observed with C18 to C21 steroids provided that the C11 position was unsubstituted. This structure activity relationship can be explained by the existence of a small alternative substrate binding pocket revealed by the AKR1D1 crystal structure. Non-steroidal anti-inflammatory drugs which are potent inhibitors of the related AKR1C enzymes do not inhibit AKR1D1. By contrast chenodeoxycholate and ursodeoxycholate were found to be potent non-competitive inhibitors suggesting that bile-acids may regulate their own synthesis at the level of AKR1D1 inhibition. << Less
Steroids 76:484-490(2011) [PubMed] [EuropePMC]
This publication is cited by 12 other entries.
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Characterization of disease-related 5beta-reductase (AKR1D1) mutations reveals their potential to cause bile acid deficiency.
Drury J.E., Mindnich R., Penning T.M.
Bile acid deficiency is a serious syndrome in newborns that can result in death if untreated. 5beta-Reductase deficiency is one form of bile acid deficiency and is characterized by dramatically decreased levels of physiologically active 5beta-reduced bile acids. AKR1D1 (aldo-keto reductase 1D1) is ... >> More
Bile acid deficiency is a serious syndrome in newborns that can result in death if untreated. 5beta-Reductase deficiency is one form of bile acid deficiency and is characterized by dramatically decreased levels of physiologically active 5beta-reduced bile acids. AKR1D1 (aldo-keto reductase 1D1) is the only known human enzyme that stereo-specifically reduces the Delta(4) double bond in 3-keto steroids and sterols to yield the 5beta-hydrogenated product. Analysis of the AKR1D1 gene in five patients with 5beta-reductase deficiency revealed five different mutations resulting in an amino acid substitution in the protein. To investigate a causal role for these observed point mutations in AKR1D1 in 5beta-reductase deficiency, we characterized their effect on enzymatic properties. Attempts to purify mutant enzymes by overexpression in Escherichia coli only yielded sufficient amounts of the P133R mutant for further characterization. This enzyme displayed a highly reduced K(m) and V(max) reminiscent of uncompetitive kinetics with 4-cholesten-7alpha-ol-3-one as substrate. In addition, this mutant displayed no change in cofactor affinity but was more thermolabile in the absence of NADPH as judged by CD spectroscopy. All mutants were compared following expression in HEK 293 cells. Although these enzymes were equally expressed based on mRNA levels, protein expression and functional activity were dramatically reduced. Cycloheximide treatment also revealed that several of the expressed mutants were less stable. Our findings show that the reported mutations in AKR1D1 in patients with 5beta-reductase lead to significantly decreased levels of active enzyme and could be causal in the development of bile acid deficiency syndrome. << Less
J. Biol. Chem. 285:24529-24537(2010) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.