Fig. 3

Purification of PPK and comparison of ATP regeneration capacity. A: Model of ATP regeneration system. B: Shake‒flask fermentation of ppk heterologously expression strains. C: SDS‒PAGE analysis of the purification of PPKs. D Specific enzyme activity assay of different PPKs using different polyP_n. The data are presented as averages, and the error bars represent standard deviations (n = 3 independent experiments). ^* 0.01 < P < 0.05, ^** P < 0.01