FIG 6.

The effects of temperature (A), pH (B), AMP concentration (C), and PPA concentration (D) on the initial reaction rates of purified wild-type ChPPK and the variant ChPPK/A79G/S106C/I108F/L285P. Four different buffers, 50 mM citric sodium citrate buffer (pH 5–6), potassium phosphate buffer (pH 6–8), borate-boric acid buffer (pH 8–9), and glycine-sodium hydroxide buffer (pH 9–10), were used in B. Reactions were performed using a purified enzyme (5 µg/mL) of wild-type ChPPK or ChPPK variant. In (A), (B), (C), and (D), the concentrations of 2.25 mM AMP and 1.6 g/L PPA were used in the reaction, unless as a variable substrate concentration.