Figure 6.
Determination of the catalytic parameters of the reductase step of D45C/S48C/S94C/S97C nmMsrB measured by fluorescence stopped-flow under single turnover kinetics. The nmMsrB fluorescence decrease was recorded on a stopped-flow apparatus at 25°C in buffer A. Final concentration of nmMsrB was 10 μM. Excitation wavelength was set at 291 nm, and emitted light was collected above 320 nm using a cutoff filter. Symbols (•) represent experimental points. Data were fit to Equation 1 by least-squares regression, which gave kobs max and KS values of 65 ± 4 sec−1 and 170 ± 30 mM, respectively.