Figure 5.

Kinetics of reduction of TyrH by ascorbate under anaerobic conditions. Fe(III)-TyrH (100 μM in 200 mM Hepes, pH 7.5, 10% glycerol, and 0.1 M KCl) was mixed with varying concentrations of ascorbate dissolved in 2 mM HCl at 20 °C. The reaction was monitored at 350 nm, and the resulting traces were fit to eq 1 to obtain the pseudo-first-order rate constants.