Enzymes
| UniProtKB help_outline | 224 proteins |
Reaction participants Show >> << Hide
- Name help_outline 4-hydroxyestrone Identifier CHEBI:87602 (CAS: 3131-23-5) help_outline Charge 0 Formula C18H22O3 InChIKeyhelp_outline XQZVQQZZOVBNLU-QDTBLXIISA-N SMILEShelp_outline C[C@]12CC[C@H]3[C@@H](CCc4c(O)c(O)ccc34)[C@@H]1CCC2=O 2D coordinates Mol file for the small molecule Search links Involved in 6 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline S-adenosyl-L-methionine Identifier CHEBI:59789 Charge 1 Formula C15H23N6O5S InChIKeyhelp_outline MEFKEPWMEQBLKI-AIRLBKTGSA-O SMILEShelp_outline C[S+](CC[C@H]([NH3+])C([O-])=O)C[C@H]1O[C@H]([C@H](O)[C@@H]1O)n1cnc2c(N)ncnc12 2D coordinates Mol file for the small molecule Search links Involved in 842 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 4-methoxyestrone Identifier CHEBI:136972 (CAS: 58562-33-7) help_outline Charge 0 Formula C19H24O3 InChIKeyhelp_outline PUEXVLNGOBYUEW-BFDPJXHCSA-N SMILEShelp_outline C1[C@]2([C@]3([C@@](C4=C(C(=C(O)C=C4)OC)CC3)(CC[C@@]2(C(=O)C1)C)[H])[H])[H] 2D coordinates Mol file for the small molecule Search links Involved in 2 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 S-adenosyl-L-homocysteine Identifier CHEBI:57856 Charge 0 Formula C14H20N6O5S InChIKeyhelp_outline ZJUKTBDSGOFHSH-WFMPWKQPSA-N SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](CSCC[C@H]([NH3+])C([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 768 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:53104 | RHEA:53105 | RHEA:53106 | RHEA:53107 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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Catechol-O-methyltransferase (COMT)-mediated metabolism of catechol estrogens: comparison of wild-type and variant COMT isoforms.
Dawling S., Roodi N., Mernaugh R.L., Wang X., Parl F.F.
The oxidative metabolism of 17beta-estradiol (E2) and estrone (E1) to catechol estrogens (2-OHE2, 4-OHE2, 2-OHE1, and 4-OHE1) and estrogen quinones has been postulated to be a factor in mammary carcinogenesis. Catechol-O-methyltransferase (COMT) catalyzes the methylation of catechol estrogens to m ... >> More
The oxidative metabolism of 17beta-estradiol (E2) and estrone (E1) to catechol estrogens (2-OHE2, 4-OHE2, 2-OHE1, and 4-OHE1) and estrogen quinones has been postulated to be a factor in mammary carcinogenesis. Catechol-O-methyltransferase (COMT) catalyzes the methylation of catechol estrogens to methoxy estrogens, which simultaneously lowers the potential for DNA damage and increases the concentration of 2-methoxyestradiol (2-MeOE2), an antiproliferative metabolite. We expressed two recombinant forms of COMT, the wild-type (108Val) and a common variant (108Met), to determine whether their catalytic efficiencies differ with respect to catechol estrogen inactivation. The His-tagged proteins were purified by nickel-nitrilo-triacetic acid chromatography and analyzed by electrophoresis and Western immunoblot. COMT activity was assessed by determining the methylation of 2-OHE2, 4-OHE2, 2-OHE1, and 4-OHE1, using gas chromatography/mass spectrometry for quantitation of the respective methoxy products. In the case of 2-OHE2 and 2-OHE1, methylation occurred at 2-OH and 3-OH groups, resulting in the formation of 2-MeOE2 and 2-OH-3-MeOE2, and 2-MeOE1 and 2-OH-3-MeOE1, respectively. In contrast, in the case of 4-OHE2 and 4-OHE1, methylation occurred only at the 4-OH group, yielding 4-MeOE2 and 4-MeOE1, respectively. Individual and competition experiments revealed the following order of product formation: 4-MeOE2 > 4-MeOE1 >> 2-MeOE2 > 2-MeOE1 > 2-OH-3-MeOE1 > 2-OH-3-MeOE2. The variant isoform differed from wild-type COMT by being thermolabile, leading to 2-3-fold lower levels of product formation. MCF-7 breast cancer cells with the variant COMT 108Met/Met genotype also displayed 2-3-fold lower catalytic activity than ZR-75 breast cancer cells with the wild-type COMT 108Val/Val genotype. Thus, inherited alterations in COMT catalytic activity are associated with significant differences in catechol estrogen and methoxy estrogen levels and, thereby, may contribute to interindividual differences in breast cancer risk associated with estrogen-mediated carcinogenicity. << Less
Cancer Res. 61:6716-6722(2001) [PubMed] [EuropePMC]
This publication is cited by 5 other entries.