Fig. 8. A relatively low mesna concentrations Inactivate MPO chlorinating activity.

A, effect of Mesna on the chlorination activity of MPO was determined by the production of hypochlorous acid by 10 nM MPO in 10 mM phosphate buffer, pH 7.4, containing 140 mM sodium chloride, 5 mM taurine and increasing concentrations of mesna (0, 2.5, 5, 8, 10, 12.5, 15 and 20). Concentration of Mesna that inhibited production of hypochlorite by 50% (IC₅₀) was determined over a range of chloride concentrations. These data are representative of three independent experiments.