This reaction in vitro requires the combined function of three pure Escherichia coli proteins, namely the Bl and B2 subunits of ribonucleotide reductase and glutaredoxin. The stoichiometry was demonstrated by determinations of the products r3H]dCDP and GSSG. The standard assay couples oxidation of NADPH to the reduction of GSSG by glutathione reductase. The apparent K,,, value of glutaredoxin w...

The bacterial peroxiredoxin AhpC, a cysteine-dependent peroxidase, can be converted through a single amino acid insertion to a disulfide reductase, AhpC*, active in the glutathione and glutaredoxin pathway. Here we show that, whereas AhpC* is inactive as a peroxidase, other point mutants in AhpC can confer the in vivo disulfide reductase activity without abrogating peroxidase activity. Moreover...

Reactive oxygen species (ROS) generated by UVA irradiation affect the keratinocyte cell membrane, DNA, and proteins and may cause serious injury to the skin. Treating human dysplastic keratinocytes (DOK) with 3-amino-1,2,4-triazole (AMT), a common catalase inhibitor, induced a compensatory mechanism for the hydrogen peroxide detoxification, which included a rise in glutathione peroxidase and gl...

The erythrocyte glutathione reductase activity was measured in 199 healthy blood donors. The normal range was found to be 6.3 to 39.0 IU/10(9) erythrocytes. There was no variation related to either age or sex.

Incubation of rat brain synaptosomal/mitochondrial fraction with tert-butylhydroperoxide resulted in accumulation of the lipid peroxidation product, conjugated dienes, damage of the synaptosomal membrane as evidenced by leakage of lactate dehydrogenase, and decrease of the total content of glutathione and of the GSH/GSSG ratio. This treatment also produced a considerable decrease of the ouabain...