Glutathione S-transferase Activity in Diagnostic Pathology

Abstract

etc. were used to collate relevant articles. The results were then crossreferenced to generate a total number of 125 references cited in this review. Functions of glutathione S-transferases The functions of GSTs have been classified into two general categories [19,20]. As intracellular binding proteins [2,21,22], GSTs function on a broad scale in solubilizing and transport of substances much as the extracellular functions of albumin described elsewhere [23,24]. The GST from rat liver, designated as transferase B, has been shown to be identical to the bilirubin binding protein or 'ligandins' [25]. Although ligandins have high affinity for endogenous compounds such as bile acids, haemin, bilirubin, fatty acids and steroids [16,18,22], whose conjugates are eventually sequestered [26], the bound GSTs are devoid of catalytic processing and do not form glutathione conjugates with their substrates [18,27]. Another specific protective role of GST as ligandin is the specific binding of intra-erythrocyte GSTP1-1 isoform to Jun-kinase, a pro-apoptotic enzyme that becomes inactive when bound to GST [26,28]. The second major function is the protection of cellular components [29,30] by the preferential reaction of electrophilic agents with GSH through the enzymatic action of GSTs, and thereby prevents the reaction of electrophiles with cellular nucleophiles. The enzyme may also detoxify certain extremely reactive substances by direct covalent binding to electrophilic agents [1,22,31]. For the most part, GSTs catalyze the conjugation of electrophilic groups of hydrophobic drugs and xenobiotics to form glutathione-thioethers [32]. These thioethers are converted to mercapturic acid by the sequential actions of γ-glutamyl transpeptidase, depeptidase and N-acetylase [2,15,33] prior to the eventual elimination of the hydrophilic conjugates. Reactive oxygen and nitrogen species (ROS/RNS) can alter the

Decreased Glutathione S-transferase Level and Neonatal Hyperbilirubinemia Associated with Glucose-6-phosphate Dehydrogenase Deficiency: A Perspective Review

“…68 Plasma GST is a potential useful marker for hepatobiliary damage. 64 The GST-mu 1 (GSTM1) gene is the most common gene expressed in the liver, and GST-theta 1 (GSTT1) gene is expressed mainly in the liver and kidneys. 44,66,69,70 GSTalpha genes (GSTA1 and GSTA2) are expressed mainly in the liver and testes.…”