pH dependence of GSTP1-1 inhibition.

<p>(A) Purified GSTP1-1 (20 pmoles) incubated with saliva (estimated inhibitor concentration 5 µM) at different pH values (from 4.3 to 8.0) with suitable additions of 0.1 M potassium dihydrogen phosphate or 0.1 M potassium monohydrogen phosphate. After incubation (1 min, 25°C) the activity was measured. (B) GSTP1-1 incubated as in (A) with authentic HOSCN 5 µM. Each experiment was performed in triplicate (i.e. three different spectrophotometric determinations on the same salivary sample). Error bars represent SEM.