FIG 2.

Demonstration of the kinetics of NfoR with and without an external oxidant. (A) NADPH consumption under aerobic conditions: 1 μM NfoR with 5 μM FMN reacting with 20, 40, 60, 80, 100, and 120 μM NADPH in the presence of 250 μM dioxygen as an oxidant and observed at 340 nm. (B) FMN consumption under anaerobic conditions: 4 μM NfoR in the presence of 150 μM NADPH reacting with 15.4, 16.4, 18.4, and 22 μM FMN and observed at 450 nm. Both data sets were fit simultaneously using numerical integration to the model depicted in Fig. 10 (red dashed line). Arrows indicate decreasing concentrations for successive assays.