Reaction: 2 γ-glutamylcysteine + NADP+ = bis-γ-glutamylcystine + NADPH + H+
Other name(s): NADPH2:bis-γ-glutamylcysteine oxidoreductase
Systematic name: γ-glutamylcysteine:NADP+ oxidoreductase
Comments: Contains FAD. The enzyme, which is found only in halobacteria, maintains the concentration of γ-glutamylcysteine, the major low molecular weight thiol in halobacteria. Not identical with EC 1.8.1.7 (glutathione-disulfide reductase) or EC 1.8.1.14 (CoA-disulfide reductase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 117056-54-9
References:
1. Sundquist, A.R. and Fahey, R.C. The novel disulfide reductase bis-γ-glutamylcystine reductase and dihydrolipoamide dehydrogenase from Halobacterium halobium: purification by immobilized-metal-ion affinity chromatography and properties of the enzymes. J. Bacteriol. 170 (1988) 3459-3467. [PMID: 3136140]
2. Sundquist, A.R. and Fahey, R.C. The function of γ-glutamylcysteine and bis-γ-glutamylcystine reductase in Halobacterium halobium. J. Biol. Chem. 264 (1989) 719-725. [PMID: 2910862]
3. Kim, J. and Copley, S.D. The orphan protein bis-γ-glutamylcystine reductase joins the pyridine nucleotide-disulfide reductase family. Biochemistry 52 (2013) 2905-2913. [PMID: 23560638]