Fig. 2.

Cys125 was the peroxidative cysteine (C_P). a, b Spectrophotometric analysis of NBD-labeled OhsR treated with or without different concentration of CHP. The proteins were analyzed spectrophotometrically at 200 to 600 nm. DTT indicates DTT-treated OhsR protein, which was as a negative control. c Quantification of free OhsR thiol levels in reduced and oxidized proteins. CHP- and DTT-treated proteins (10 μM) were mixed 2 mM with DTNB in 50 mM Tris–HCl buffer (pH 8.0), and the absorbance was monitored at 412 nm against a 2 mM DTNB solution as reference. These data are means of the values obtained from three independent assays. d Spectrophotometric analysis of NBD-labeled OhsR treated with or without different concentration of H₂O₂