Thioredoxin Reductase Activity

Thioredoxin Reductase (TrxR) activity was measured using a Thioredoxin Reductase Assay Kit (Sigma-Aldrich, Germany) according to the manufacturer’s protocol. Tissue was homogenized (1/5; w/v), centrifuged (12,000×g, 5 min, 4 °C) and supernatant was used for analysis of enzyme activity and protein determination. Protein extract was used in a reaction mixture, addition of 5,5-dithiobis-(2-nitrobenzoic acid) (DTNB) solution initiated the reaction and the change in absorbency caused by 2-nitro-5-thiobenzoic acid (TNB) production was measured after 1 min at 415 nm. The results are presented as nmol TNB/min/mg of protein.