FIGURE 4.

Michaelis-Menten reaction kinetics of NWMN2274 with IsdI-heme or IsdG-heme as the substrate. Reactions were conducted with 0.1 μm NWMN2274, 600 μm NADPH, and 1–25 μm IsdG-heme or IsdI-heme. Initial enzyme velocities were calculated for 30 s of the reaction and plotted against the concentration of IsdG-heme (red) or IsdI-heme (blue). Non-linear regression was used to fit data to Michaelis-Menten kinetics. Data points and error bars represent the mean S.E. for reactions from four (IsdG-heme) or five (IsdI-heme) independent experiments.