Glutathione-related enzyme system: Glutathione reductase (GR), glutathione Transferases (GSTs) and glutathione peroxidases (GPXs)

J. Csiszár, E. Horváth, K. Bela, Gallé

Research output: Chapter in Book/Report/Conference proceedingChapter

5 Citations (Scopus)

Abstract

The glutathione-related enzymes are usually considered to accompany the main non-enzymatic antioxidative compounds of the ascorbate-glutathione cycle. Taking into account that the redox processes are not spontaneous in cells, but the adequate reaction velocity and appropriate specificity are achieved by the catalyzing activity of enzymes, special attention has raised toward the glutathione-utilizing enzymes. Glutathione reductase (GR) is a NADPH-dependent oxidoreductase which catalyzes the conversion of oxidized glutathione (GSSG) to reduced glutathione (GSH). Some members of the diverse glutathione transferase (GST) enzyme family have GSH-dependent thiol transferase activity and participate in the recycling of antioxidants (ascorbate, flavonoids, quinones), while other isoenzymes, due to their S-transferase activity, are involved in the detoxification mechanisms using GSH as co-substrate. A significant portion of GST isoenzymes also has glutathione peroxidase activity and can convert lipid peroxides and other peroxides to less harmful compounds. The plant glutathione peroxidase enzymes (GPXs) may be involved in the detoxification of H2O2 and organic hydroperoxides and in the regulation of the cellular redox homeostasis by maintaining the thiol/disulfide balance. Most of plant GPXs prefer to use thioredoxin (TRX) instead of glutathione as a reducing agent, and it is thought that the GPXs may represent a link between the glutathione- and the thioredoxin-based system. The GR, GPX and some GST isoenzymes have Cys in their active center and thus are directly regulated by redox status. This chapter summarizes their roles in stress responses as antioxidant enzymes, in determining the redox status of cells, and emphasizes their connection to redox signaling mechanisms.

Original languageEnglish
Title of host publicationRedox State as a Central Regulator of Plant-Cell Stress Responses
PublisherSpringer International Publishing
Pages137-158
Number of pages22
ISBN (Electronic)9783319440811
ISBN (Print)9783319440804
DOIs
Publication statusPublished - Jan 1 2016

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Keywords

  • Antioxidant enzymes
  • Glutathione
  • Reactive oxygen species
  • Redox homeostasis
  • Redox regulation

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Csiszár, J., Horváth, E., Bela, K., & Gallé (2016). Glutathione-related enzyme system: Glutathione reductase (GR), glutathione Transferases (GSTs) and glutathione peroxidases (GPXs). In Redox State as a Central Regulator of Plant-Cell Stress Responses (pp. 137-158). Springer International Publishing. https://doi.org/10.1007/978-3-319-44081-1_7