Reactivity of γ‐glutamyl‐cysteine with intracellular and extracellular glutathione metabolic enzymes. Issue 2 (29th December 2021)

• Record Type: Journal Article
• Authors: Muraoka, Misa; Yoshida, Saki; Ohno, Moeka; Matsuura, Hideyuki; Nagano, Kazuya; Hirata, Yoshihiko; Arai, Masayoshi; Hirata, Kazumasa
• Is Part Of: FEBS letters. Volume 596:Issue 2(2022)
• Page Start: 180
• Page End: 188
• Publication Date: 2021-12-29
• Subjects: antioxidant defence -- gamma‐glutamyl‐cysteine -- glutathione -- glutathione metabolic enzyme; Biochemistry -- Periodicals; Biophysics -- Periodicals; Molecular biology -- Periodicals; Biochimie -- Périodiques; Biochemistry; Biophysics; Molecular biology; Periodicals; 572.05
• DOI: 10.1002/1873-3468.14261
• Languages: English
• ISSNs: 0014-5793

Abstract

Abstract : Gamma‐glutamyl‐cysteine (γ‐EC) is a precursor of glutathione (GSH) biosynthesis. We investigated whether it functions as a substrate for three intracellular and one extracellular GSH metabolic enzymes, which mediate the antioxidant defence function of GSH. Among them, glutathione peroxidase, glutathione S ‐transferase and γ‐glutamyl transferase (GGT) exhibited substrate specificity for γ‐EC, whereas glutathione reductase did not. The specificities of γ‐EC and its disulphide form to GGT were comparable to GSH and its oxidized form, GSSG respectively. These results indicate that they can supply GSH constituent amino acids, glutamate, cysteine and cystine through degradation by GGT. γ‐EC may contribute valuable antioxidant defence properties as a food and cosmetic additive. Abstract : This study investigates whether gamma‐glutamyl‐cysteine (γ‐EC) functions as a substrate for glutathione (GSH) metabolic enzymes, which mediate the antioxidant defence. Glutathione peroxidase (GPx), glutathione S ‐transferase (GST) and γ‐glutamyl transferase (GGT) exhibited substrate specificity for γ‐EC, whereas glutathione reductase (GR) did not. The specificities of γ‐EC and its disulphide form to GGT were comparable to GSH and its oxidized form, GSSG respectively.