title: Rapid colorimetric determination of reduced and oxidized glutathione using an end point coupled enzymatic assay.
abstract: A simple and rapid colorimetric coupled enzymatic assay for the determination of glutathione is described. The proposed method is based on the specific reaction catalyzed by γ-glutamyltransferase, which transfers the γ-glutamyl moiety from glutahione to an acceptor, with the formation of the γ-glutamyl derivative of the acceptor and cysteinylglycine. The latter dipeptide is a substrate of leucyl aminopeptidase, which hydrolyzes cysteinylglycine to glycine and cysteine that can be easily measured spectrophotometrically. The proposed method was used to measure the content of glutathione in acid extracts of bovine lens, to follow the NADPH-dependent reduction of glutathione disulfide (GSSG) to reduced glutathione (GSH) catalyzed by the enzyme glutathione reductase and to determine the glutathione content in human astrocytoma ADF cells subjected to oxidative stress. The results obtained showed that the method can be suitably used for the determination of GSH and GSSG in different biological samples and to monitor tissue or cell redox status under different conditions. It is also applicable for following reactions involving GSH and/or GSSG.
authors.affiliation: Department of Biology, Biochemistry Unit, University of Pisa, Pisa, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Cappiello
authors.forename: Eleonora
authors.initials: E
authors.lastname: Peroni
authors.forename: Ambra
authors.initials: A
authors.lastname: Lepore
authors.forename: Roberta
authors.initials: R
authors.lastname: Moschini
authors.forename: Antonella
authors.initials: A
authors.lastname: Del Corso
authors.forename: Francesco
authors.initials: F
authors.lastname: Balestri
authors.forename: Umberto
authors.initials: U
authors.lastname: Mura
mesh_terms: D000818:Animals; D001254:Astrocytoma / Q000378:metabolism; D002417:Cattle; D045744:Cell Line, Tumor; D003124:Colorimetry / Q000191:economics / Q000379:methods*; D057075:Enzyme Assays / Q000191:economics / Q000379:methods*; D005978:Glutathione / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D007908:Lens, Crystalline / Q000737:chemistry*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D005723:gamma-Glutamyltransferase; D005978:Glutathione