Glutathione S-transferase families

Hence, reduction of inorganic As(V) and complexation of inorganic As(III) by GSH was a plausible mechanism in cellular environments. However, some data suggest that the rate for complexation of inorganic As(III) by GSH may be too slow to account for the rates of formation that are observed in cells (Spuches, 2005). This suggests that this reaction could be enzymatically catalyzed, possibly by members of the glutathione-S-transferase family (Thomas, 2007). 

Strange RC, Spiteri MA, Ramachandran S, Fryer AA (2001) Glutathione-S-transferase family of enzymes. Mutat Res Fundam Mol Mech Mutagen 482 21-26... 

Considerable interest was generated when it was shown that substantial GSHPx activity exists in liver of selenium-depleted rats when LOOH is used as substrate but not H2O2 [20]. The enzyme was subsequently shown to be identical to a member of the glutathione-S-transferase family of enzymes [20,21,48], The enzyme was for a time called selenium-independent , or non-selenium dependent GSHPx and this nomenclature, which is confusing, has persisted in the literature. The role of GSH-S-transferases in the overall protection of cells against the harmful potential of LOOH has not been determined but it undoubtedly must form part of that protective mechanism. 

Once bilirubin enters the hepatocytes, it can bind to certain cytosolic proteins, which help to keep it solubilized prior to conjugation. Ligandin (a family of glutathione S-transferases) and protein Y are the involved proteins. They may also help to prevent efflux of bilirubin back into the blood stream. 

Figure 32-15. Diagrammatic representation of the three major processes (uptake, conjugation, and secretion) involved in the transfer of bilirubin from blood to bile. Certain proteins of hepatocytes, such as ligandin (a family of glutathione S-transferase) and Y protein, bind intracellular bilirubin and may prevent its efflux into the blood stream. The process affected in a number of conditions causing jaundice is also shown.

Hayes, J.D. and Pulford, D.J. (1995) The glutathione S-transferase supergene family regulation of GST and the contribution of the isoenzymes to cancer chemoprotection and drug resistance. Critical Reviews in Biochemistry and Molecular Biology, 30, 445-600. 

Glutathione-dependent peroxidases family includes two main enzymes — Se-contained glutathione peroxidase [20] and glutathione-S-transferase [21,22] utilizing lipohydroperoxides and preventing the production of alkoxyl radicals also play an important role in the regulation of lipid peroxidation in cells ... 

GSTP1 gene it is part of the Glutathione S-transferases, a family of enzymes that catalyse conjugation of many hydrophobic and electrophilic compounds with reduced glutathione, covering an important role in detoxification [4-6], See further, for more details. 

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