The apparent glutathione oxidase activity of gamma-glutamyl transpeptidase. Chemical mechanism. Academic Article uri icon

Overview

MeSH Major

  • Glutathione
  • gamma-Glutamyltransferase

abstract

  • The apparent glutathione oxidase activity of gamma-glutamyl transpeptidase is due to nonenzymatic oxidation and transhydrogenation reactions of cysteinylglycine, an enzymatic product formed from glutathione by hydrolysis or autotranspeptidation. Since cysteinylglycine reacts with oxygen more rapidly than does glutathione, the rate of disulfide formation is increased and either cystinyl-bis-glycine or the mixed disulfide of cysteinylglycine and glutathione forms as an intermediate product. Nonenzymatic transhydrogenation reactions of these disulfides with glutathione yield glutathione disulfide and thus account for the apparent glutathione oxidase activity of gamma-glutamyl transpeptidase. A sensitive assay for glutathione oxidation is described, and it is shown that covalent inhibitors of gamma-glutamyl transpeptidase abolish the oxidase activity of the purified enzyme and of crude homogenates of mouse and rat kidney.

publication date

  • June 10, 1980

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed ID

  • 6102993

Additional Document Info

start page

  • 5011

end page

  • 4

volume

  • 255

number

  • 11