Inhibition of purified GSTP1-1 by H₂O₂.

<p>GSTP1-1 (20 pmoles) was incubated at 25°C with two different concentrations of H₂O₂, 10 µM, corresponding to the physiological level (open triangle) and 100 µM (open square) in 70 µl potassium phosphate buffer, pH 7.0. For comparison GSTP1-1 (20 pmoles) was also incubated with 70 µl of saliva (open circle). Each experiment was performed in triplicate (i.e. three different spectrophotometric determinations on the same sample). Error bars represent SEM.