Glutathione S-Transferase
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See: Glutathione S-Transferase Enzyme, Glutathione S-Transferanse Enzyme Family.
References
- (Wikipedia, 2009) ⇒ http://en.wikipedia.org/wiki/Glutathione_S-transferase
- Enzymes of the glutathione S-transferase (GST) family are composed of many cytosolic, mitochondrial, and microsomal proteins. GSTs catalyse a variety of reactions and accept endogenous and xenobiotic substrates. They are members of MAPEG family of transmembrane proteins.
- GSTs can constitute up to 10% of cytosolic protein in some mammalian organs. [1] GSTs catalyse the conjugation of reduced glutathione — via a sulfhydryl group — to electrophilic centers on a wide variety of substrates. [2] This activity detoxifies endogenous compounds such as peroxidised lipids [3], as well as breakdown of xenobiotics. GSTs may also bind toxins and function as transport proteins, and, therefore, an early term for GSTs was “ligandin”[4].
- The mammalian GST super-family consists of cytosolic dimeric isoenzymes of 45–55 kDa size that have been assigned to at least four classes: Alpha, Mu, Pi and Theta. [5] Most mammalian isoenzymes have affinity for the substrate 1-chloro-2, 4-dinitrobenzene (CDNB), and spectrophotometric assays utilising this substrate are commonly used to report GST activity[6]. However, some endogenous compounds, e.g., bilirubin, can inhibit the activity of GSTs. In mammals, GST isoforms have cell specific distributions (e.g., alpha GST in hepatocytes and pi GST in the biliary tract of the human liver). [7]
- Gene Ontology http://amigo.geneontology.org/cgi-bin/amigo/term-details.cgi?term=GO:0004364&session_id=3029amigo1244034791
- Accession: GO:0004364
- Ontology: molecular function
- molecular function
- Synonyms
- exact: glutathione conjugation reaction
- exact: glutathione S-alkyl transferase activity
- exact: glutathione S-alkyltransferase activity
- exact: glutathione S-aralkyltransferase activity
- exact: glutathione S-aryltransferase activity
- exact: glutathione S-transferase activity
- exact: RX:glutathione R-transferase activity
- exact: S-(hydroxyalkyl)glutathione lyase activity
- Definition
- Catalysis of the reaction: R-X + glutathione = H-X + R-S-glutathione. R may be an aliphatic, aromatic or heterocyclic group; X may be a sulfate, nitrile or halide group. [source: EC:2.5.1.18]