FIGURE 5.
Cyclic voltammetry of the W66Y variant as a function of pH. A, cyclic voltammograms were collected at a scan rate of 50 mV/s (sodium phosphate buffer (20 mm)) at pH 5.0, 6.0, 7.0, and 8.0). B, pH dependence of the Em of wild-type IsdI (filled circle) and the W66Y variant (open circle). The solid line represents the least-squares fit to the data for wild-type IsdI (slope, −49 mV/pH). The least-squares fit for the variant is identical within experimental error. SHE, standard hydrogen electrode.