FIG. 4. Saturation kinetic profiles for the determination of wild-type HI0607 kinetic parameters.

A, increasing concentration of NADP⁺ with shikimate at saturation, K_m(NADP+) = 34 µm. B, increasing concentration of shikimate with NADP⁺ at saturation, K_m(shikimate) = 234 µm. The enzymatic rate, v, was calculated by monitoring the rate of reduction of NADP⁺ at 340 nm (ϵ = 6220 m⁻¹ cm⁻¹). In each case V_max was calculated to be 10 µm/min. C, pH rate profile of HI0607 under saturating conditions for both shikimate and NADP⁺. The shape of the profile (with a pH optimum of 8.8 and a calculated pK of 8.1) indicates the dependence on deprotonation of a group for enzyme catalysis.