Glutathione Peroxidase Cellular Activity Assay Kit 

Cellular glutathione peroxidase¹ (EC 1.11.1.9) or c-GPx is a member of a family of GPx enzymes² whose function is to detoxify peroxides in the cell. Peroxides can decompose to form highly reactive free radicals which cause damage to the cell, and the GPx enzymes play a crucial role in protecting the cell from this damage, particularly lipid peroxidation.
Levels of cellular glutathione peroxidase (c-GPx) are a reflection of pathogenic state of the cell. For example, there is a marked increase in the level of glutathione peroxidase in reticulocytes in diabetic rats and normal levels are restored after administration of insulin.³ A decrease in the level of GPx has been observed in Favism (a disease associated with extreme hemolytic crisis)⁴ and in patients suffering from hairy cell leukemia.⁵
This kit can be used to assay glutathione peroxidase in tissue extracts. The assay is based on the oxidation of glutathione (GSH) to oxidized glutathione (GSSG) catalyzed by GPx coupled to the recycling of GSSG back to GSH utilizing glutathione reductase and NADPH. The decrease in NADPH absorbance measured at 340 nm during the oxidation of NADPH to NADP is indicative of glutathione peroxidase activity since the enzyme is the rate-limiting factor of the coupled reactions.^1,6 This kit was tested with rabbit reticulocyte lysate and with glutathione peroxidase enzyme.

sufficient for 100 tests

wet ice

−20°C

1. Paglia, D.E., and Valentine, W.N., Studies on the quantitative and qualitative characterization of erythrocyte glutathione peroxidase. J. Lab. Clin. Med. 70, 158-169, (1967) abstract

2. Ursini, F., et al., Diversity of glutathione peroxidases. Meth. Enzymol. 252, 38-53, (1995) abstract

3. Gupta, B.L., and Baquer, N.Z., Hexokinase, glucose-6-phosphate dehydrogenase and antioxidant enzymes in diabetic reticulocytes: effects of insulin and vanadate. Biochem. Mol. Biol. Int. 46, 1145-1152, (1998) abstract

4. Mavelli, I., et al., Favism: a hemolytic disease associated with increased superoxide dismutase and decreased glutathione peroxidase activities in red blood cells. Eur. J. Biochem. 139, 13-18, (1984) abstract

5. Arruda, V.R., et al., Glutathione peroxidase, reduced glutathione, superoxide dismutase and catalase in red cells of patients with hairy cell leukemia. Neoplasia 43, 99-102, (1996)

6. Beutler, E., et al., International Committee for Standardization in Haematology: recommended methods for red-cell enzyme analysis. Br. J. Haematol. 35, 331-340, (1977) abstract

UN 3316 9/PG 3

tert-Butyl hydroperoxide 1 mL

Glutathione Peroxidase Assay Buffer 120 mL

NADPH Assay Reagent 5 vials