Glutathione reductase (GR; EC 1.6.4.2) activity was assayed according to Foyer and Halliwell (1976). The reaction mixture contained 0.025 M sodium phosphate buffer (pH 7.8), 0.5 mM GSSG, 0.12 mM NADPHNa
and 0.1 ml enzyme extract in a final assay volume of 1 ml. The decrease in absorbance at 340 nm was recorded for 3 min. One unit of enzymatic activity was defined as the amount of the enzyme that caused a change of 0.01 in absorbance per minute and causes changes in substrate (on a molecular weight basis). The specific GR activity was expressed as mol/min/g and per g is on the protein basis.
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