Related Experiment Video
Updated: Aug 25, 2026

Spectrophotometric Screening for Potential Inhibitors of Cytosolic Glutathione S-Transferases
Published on: October 10, 2020
Characterization of a class alpha glutathione-S-transferase with glutathione peroxidase activity in human liver
K Sandeep Prabhu1, Padala V Reddy, Emily C Jones
1Department of Veterinary Science and The Center for Molecular Toxicology and Carcinogenesis, 115 Henning Building, The Pennsylvania State University, University Park, PA 16802, USA.
Abstract:
A 25.5kDa class alpha glutathione S-transferase (GST) designated as microsomal Ya-GST or M-GSTA has been purified to electrophoretic homogeneity from human liver microsomes. Limited proteolysis, gel filtration chromatography followed by EDTA, and alkaline Na(2)CO(3) treatments of microsomes indicate that the M-GSTA is intrinsic to the microsomes. Western immunoblot analysis revealed that human liver M-GSTA and the previously reported 17-kDa microsomal GST (FEBS Lett. 315 (1993) 77) did not have immunological cross reactivity. The enzyme showed conjugation activity towards substrates like 1-chloro-2,4-nitrobenzene (CDNB) and 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, and 4-hydroxy-2-nonenal (4-HNE), a genotoxic alpha,beta-unsaturated aldehyde product of lipid peroxidation. In addition, the M-GSTA exhibited significant glutathione peroxidase activity towards physiologically relevant fatty acid hydroperoxides as well as phosphatidylcholine hydroperoxide, but not with H(2)O(2). C-terminal amino acid sequence analysis revealed a high homology with the human liver cytosolic GST-A1 and A3 isozymes. Western immunoblot analyses of the microsomes prepared from human hepatoblastoma (HepG2) showed that the expression of this M-GSTA was induced upon treatment with such prooxidants as H(2)O(2), suggesting that it may play an important role in the protection of cellular membranes from peroxidative damage.
More Related Videos
03:35Rapid Quantification of Oxidized and Reduced Forms of Glutathione Using Ortho -phthalaldehyde in Cultured Mammalian Cells In Vitro
Published on: June 28, 2024
10:16In Vitro Enzyme Measurement to Test Pharmacological Chaperone Responsiveness in Fabry and Pompe Disease
Published on: December 20, 2017
Related Concept Videos
Phase II Reactions: Glutathione Conjugation and Mercapturic Acid Formation
Several distinctive characteristics distinguish glutathione conjugation from other phase II...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Jaundice