Enzymes
| UniProtKB help_outline | 591 proteins |
Reaction participants Show >> << Hide
- Name help_outline all-trans-retinal Identifier CHEBI:17898 (CAS: 116-31-4) help_outline Charge 0 Formula C20H28O InChIKeyhelp_outline NCYCYZXNIZJOKI-OVSJKPMPSA-N SMILEShelp_outline [H]C(=O)\C=C(/C)\C=C\C=C(/C)\C=C\C1=C(C)CCCC1(C)C 2D coordinates Mol file for the small molecule Search links Involved in 9 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline O2 Identifier CHEBI:15379 (CAS: 7782-44-7) help_outline Charge 0 Formula O2 InChIKeyhelp_outline MYMOFIZGZYHOMD-UHFFFAOYSA-N SMILEShelp_outline O=O 2D coordinates Mol file for the small molecule Search links Involved in 2,648 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
reduced [NADPH—hemoprotein reductase]
Identifier
RHEA-COMP:11964
Reactive part
help_outline
- Name help_outline FMNH2 Identifier CHEBI:57618 (Beilstein: 6258176) help_outline Charge -2 Formula C17H21N4O9P InChIKeyhelp_outline YTNIXZGTHTVJBW-SCRDCRAPSA-L SMILEShelp_outline Cc1cc2Nc3c([nH]c(=O)[nH]c3=O)N(C[C@H](O)[C@H](O)[C@H](O)COP([O-])([O-])=O)c2cc1C 2D coordinates Mol file for the small molecule Search links Involved in 771 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline all-trans-retinoate Identifier CHEBI:35291 Charge -1 Formula C20H27O2 InChIKeyhelp_outline SHGAZHPCJJPHSC-YCNIQYBTSA-M SMILEShelp_outline CC(\C=C\C1=C(C)CCCC1(C)C)=C/C=C/C(C)=C/C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 8 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 H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,048 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
oxidized [NADPH—hemoprotein reductase]
Identifier
RHEA-COMP:11965
Reactive part
help_outline
- Name help_outline FMN Identifier CHEBI:58210 Charge -3 Formula C17H18N4O9P InChIKeyhelp_outline ANKZYBDXHMZBDK-SCRDCRAPSA-K SMILEShelp_outline C12=NC([N-]C(C1=NC=3C(N2C[C@@H]([C@@H]([C@@H](COP(=O)([O-])[O-])O)O)O)=CC(=C(C3)C)C)=O)=O 2D coordinates Mol file for the small molecule Search links Involved in 781 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:42088 | RHEA:42089 | RHEA:42090 | RHEA:42091 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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Biosynthesis of all-trans-retinoic acid from all-trans-retinol: catalysis of all-trans-retinol oxidation by human P-450 cytochromes.
Chen H., Howald W.N., Juchau M.R.
Oxidative conversion of all-trans-retinol (t-ROH) to all-trans-retinal (t-RAL) is recognized as the rate-limiting step for biosynthesis of all-trans-retinoic acid from t-ROH in mammalian hepatic tissues. The purpose of this study was to investigate the role of human cytochrome P-450 (CYP)-dependen ... >> More
Oxidative conversion of all-trans-retinol (t-ROH) to all-trans-retinal (t-RAL) is recognized as the rate-limiting step for biosynthesis of all-trans-retinoic acid from t-ROH in mammalian hepatic tissues. The purpose of this study was to investigate the role of human cytochrome P-450 (CYP)-dependent monooxygenation in the conversion of t-ROH to t-RAL. Adult human liver microsomes (HLMS) were incubated with t-ROH, and retinoids generated were identified and quantified by liquid chromatography-mass spectroscopy, HPLC, and other methods. HLMS-catalyzed generation of t-RAL from t-ROH was primarily NADPH-dependent and was strongly inhibited by carbon monoxide. Rates of reactions increased linearly with time and concentrations of HLMS, and exhibited classical substrate saturation. These observations strongly indicated that the reaction proceeded via CYP-catalyzed monooxygenation. On the basis of responses to selective chemical inhibitors, isoforms from CYP family 1 and the CYP3A subfamily appeared to be very active. Members of the CYP2C subfamily and CYP2D6 exhibited lesser activities and CYP2A6, CYP2B6, and CYP2E1 were virtually inactive. cDNA-expressed human CYP enzymes (CYP SUPERSOMES) also were used to assess the capacity of individual CYP enzymes to catalyze the reaction. Based on responses to selective chemical inhibitors, specific activities, and levels present in adult human hepatic tissues, CYP1A2 and CYP3A4 strongly appeared to be the major CYP enzymes catalyzing hepatic oxidative conversion of t-ROH to t-RAL in the adult human liver. CYP1A1 and CYP1B1 SUPERSOMES both exhibited exceptionally high activities, and in extrahepatic tissues, these isoforms could play important roles in biosynthesis of all-trans-retinoic acid from t-ROH. << Less
Drug Metab. Dispos. 28:315-322(2000) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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Characterization of the cytochrome P450 CYP2J4: expression in rat small intestine and role in retinoic acid biotransformation from retinal.
Zhang Q.Y., Raner G., Ding X., Dunbar D., Coon M.J., Kaminsky L.S.
The sites of expression in the small intestine and the function of CYP2J4, a recently identified rat cytochrome (P450) isoform found to be predominantly expressed in the small intestine, were characterized. Immunoblot analysis with a polyclonal antibody to heterologously expressed CYP2J4 revealed ... >> More
The sites of expression in the small intestine and the function of CYP2J4, a recently identified rat cytochrome (P450) isoform found to be predominantly expressed in the small intestine, were characterized. Immunoblot analysis with a polyclonal antibody to heterologously expressed CYP2J4 revealed that expression of CYP2J4 was at the highest level in the distal duodenum and jejunum and decreased toward the ileum. Villous cells expressed higher levels of CYP2J4 than crypt cells. Isoform-specific RNA polymerase chain reaction indicated that a related P450 isoform, CYP2J3, was only a minor form in rat small intestine. Since the intestinal mucosa is exposed to high levels of dietary nutrients, we hypothesized that CYP2J4 may be active toward diet-derived factors. We determined that purified, heterologously expressed CYP2J4 is active toward all-trans- and 9-cis-retinal in reconstituted systems, producing the corresponding retinoic acids as the major products. Apparent K(m) values for the formation of retinoic acids were 54 and 49 microM, respectively, and apparent Vmax values were 20 and 21 nmol/min/nmol P450, respectively. These activities were readily inhibited by a polyclonal anti-CYP2J4 antibody. Rat enterocyte microsomes were also active with all-trans-retinal to produce all-trans-retinoic acid in the presence of NADPH, and the majority of retinoic acid synthesis activity was inhibited by the polyclonal anti-CYP2J4 antibody. These findings suggest that CYP2J4 plays a major role in intestinal microsomal metabolism of retinal to retinoic acid and may be involved in the maintenance of retinoid homeostasis in the small intestine in vivo. << Less
Arch. Biochem. Biophys. 353:257-264(1998) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.