Enzymes
| UniProtKB help_outline | 4 proteins |
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- Name help_outline (2S)-2-aminobutanoate Identifier CHEBI:74359 Charge 0 Formula C4H9NO2 InChIKeyhelp_outline QWCKQJZIFLGMSD-VKHMYHEASA-N SMILEShelp_outline CC[C@H]([NH3+])C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 16 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline L-glutamate Identifier CHEBI:29985 (CAS: 11070-68-1) help_outline Charge -1 Formula C5H8NO4 InChIKeyhelp_outline WHUUTDBJXJRKMK-VKHMYHEASA-M SMILEShelp_outline [NH3+][C@@H](CCC([O-])=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 249 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline ATP Identifier CHEBI:30616 (Beilstein: 3581767) help_outline Charge -4 Formula C10H12N5O13P3 InChIKeyhelp_outline ZKHQWZAMYRWXGA-KQYNXXCUSA-J SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,328 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline γ-L-glutamyl-(2S)-2-aminobutanoate Identifier CHEBI:189406 Charge -1 Formula C9H15N2O5 InChIKeyhelp_outline FUZOZPRKGAXGOB-WDSKDSINSA-M SMILEShelp_outline CC[C@@H](C(=O)[O-])NC(=O)CC[C@@H](C(=O)[O-])[NH3+] 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 ADP Identifier CHEBI:456216 (Beilstein: 3783669) help_outline Charge -3 Formula C10H12N5O10P2 InChIKeyhelp_outline XTWYTFMLZFPYCI-KQYNXXCUSA-K SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 865 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline phosphate Identifier CHEBI:43474 Charge -2 Formula HO4P InChIKeyhelp_outline NBIIXXVUZAFLBC-UHFFFAOYSA-L SMILEShelp_outline OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 1,029 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 9,932 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:72067 | RHEA:72068 | RHEA:72069 | RHEA:72070 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Expression and purification of human gamma-glutamylcysteine synthetase.
Misra I., Griffith O.W.
gamma-Glutamylcysteine synthetase (gamma-GCS) catalyzes the ATP-dependent ligation of L-glutamate and L-cysteine to form L-gamma-glutamyl-L-cysteine; this is the first and rate-limiting step in glutathione biosynthesis. Inhibitors of gamma-GCS such as buthionine sulfoximine are widely used as tool ... >> More
gamma-Glutamylcysteine synthetase (gamma-GCS) catalyzes the ATP-dependent ligation of L-glutamate and L-cysteine to form L-gamma-glutamyl-L-cysteine; this is the first and rate-limiting step in glutathione biosynthesis. Inhibitors of gamma-GCS such as buthionine sulfoximine are widely used as tools for elucidating glutathione metabolism in vivo and as pharmacological agents for reversing glutathione-based resistance to chemotherapy and radiation therapy in certain cancers. Although gamma-GCS is readily isolated from rat kidneys, future drug design efforts are better based on structure-activity relationships established with the human enzyme. We report here the coexpression in Escherichia coli BL21(DE3) of the human gamma-GCS catalytic (heavy) subunit and regulatory (light) subunit using pET-3d and pET-9d vectors, respectively. Intracellular assembly of the holoenzyme occurred without difficulty, and levels of expression were acceptable (approximately 32 mg holoenzyme/100 g cells). Recombinant human gamma-GCS was purified to homogeneity in an overall yield of 45% by ammonium sulfate fractionation followed by sequential chromatography on Q-Sepharose ion-exchange, Superdex 200 gel filtration and ATP-affinity resins. Trace amounts of E. coli gamma-GCS were removed by immunoaffinity chromatography. The specific activity of the isolated enzyme was >1500 units/mg, comparable to the best preparations from rat kidney. The Km values for L-glutamate, L-cysteine, L-gamma-aminobutyrate (an L-cysteine surrogate), and ATP are 1.8, 0.1, 1.3, and 0.4 mM, respectively. Recombinant human gamma-GCS, like native rat gamma-GCS, is feedback inhibited by glutathione and is potently inhibited by buthionine sulfoximine and cystamine. << Less
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Differential metabolomics reveals ophthalmic acid as an oxidative stress biomarker indicating hepatic glutathione consumption.
Soga T., Baran R., Suematsu M., Ueno Y., Ikeda S., Sakurakawa T., Kakazu Y., Ishikawa T., Robert M., Nishioka T., Tomita M.
Metabolomics is an emerging tool that can be used to gain insights into cellular and physiological responses. Here we present a metabolome differential display method based on capillary electrophoresis time-of-flight mass spectrometry to profile liver metabolites following acetaminophen-induced he ... >> More
Metabolomics is an emerging tool that can be used to gain insights into cellular and physiological responses. Here we present a metabolome differential display method based on capillary electrophoresis time-of-flight mass spectrometry to profile liver metabolites following acetaminophen-induced hepatotoxicity. We globally detected 1,859 peaks in mouse liver extracts and highlighted multiple changes in metabolite levels, including an activation of the ophthalmate biosynthesis pathway. We confirmed that ophthalmate was synthesized from 2-aminobutyrate through consecutive reactions with gamma-glutamylcysteine and glutathione synthetase. Changes in ophthalmate level in mouse serum and liver extracts were closely correlated and ophthalmate levels increased significantly in conjunction with glutathione consumption. Overall, our results provide a broad picture of hepatic metabolite changes following acetaminophen treatment. In addition, we specifically found that serum ophthalmate is a sensitive indicator of hepatic GSH depletion, and may be a new biomarker for oxidative stress. Our method can thus pinpoint specific metabolite changes and provide insights into the perturbation of metabolic pathways on a large scale and serve as a powerful new tool for discovering low molecular weight biomarkers. << Less
J. Biol. Chem. 281:16768-16776(2006) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.