Fig. 2.

Glutathione disulfide reduction by hGR, hTrxR1, BmTrxR isoform D or OvTrxR isoform D with or without coupling to Trx. Absorption at 340 nm was followed in a reaction containing 1 mM GSSG as substrate together with 15 nM of each respective reductase and 0.25 mM NADPH, with or without addition of 25 μM thioredoxin, as indicated. NADPH consumption in the reaction was quantified using a standard curve of pure NADPH. Error bars represent standard deviation of the mean.