Figure 5.
Oxidative half-reaction of sfALR. The 2-electron reduced enzyme (Experimental Procedures) was mixed with aerobic buffer to give final concentration of 30 μM enzyme and 120 μM oxygen. Spectra were recorded in the diode-array stopped-flow instrument 0.005, 0.055, 0.105, 0.155, 0.215, 0.285, 0.365 and 0.505 s after mixing (spectra 1–8 respectively). The inset plots the dependence on the apparent first-order rate constants for the return of the oxidized flavin at 454 nm as a function of dissolved oxygen concentration. Data points represent the average of 4 experiments at each oxygen concentration.