Figure 5.

Single-turnover rapid-reaction kinetic data for wild-type BjPutA and mutant D779Y. (A) Wild-type BjPutA (21.3 μM) and (B) BjPutA mutant D779Y (17.9 μM) were incubated with 100 μM NAD⁺ and rapidly mixed with 40 mM proline (all concentrations reported as final) and monitored by stopped-flow multiwavelength absorption (300–700 nm). Insets showing FAD (451 nm) and NAD⁺ (340 nm) reduction vs time fit to a single-exponential equation to obtain the observed rate constant (k_obs) of FAD and NAD⁺ reduction. Note that the inset in panel B is on a longer time scale.