FIG 5.

Identification of the best variant ChPPK/A79G/S106C/I108F. The relative activities of the purified wild-type ChPPK and ChPPK variants containing multiple beneficial mutations. Enzymatic activity assays were performed for purified enzymes (5 µg/mL) of wild-type ChPPK or ChPPK variants in the presence of 1.6 g/L PPA and 2.25 mM AMP. The ATP concentration after incubation was measured by HPLC. One unit of enzyme activity was given as the amount of enzyme that synthesized 1 µM ATP from AMP per minute during the initial minute.