FIGURE 4.

Formation and decay of Fe(IV) = OPor⁺· in WT KatG and KatG[S315G].⁵ Extended time traces (at 407 nm) recorded after mixing 5 μm resting WT KatG or KatG[S315G] with 25 μm PAA (final concentrations) in 20 mm potassium phosphate buffer, pH 7.2, at 25 °C. The initial rapid decrease is followed by the slow return to the starting absorbance value around 0.5.