FIG. 2.

Effect of pH on the synthesis of 5′-IMP. The time course of 5′-IMP synthesis was measured at different pHs with 0.1 M sodium acetate buffer: pH 3.5 (○), pH 4.0 (●), pH 5.0 (□), pH 5.5 (▴), and pH 6.0 (▵). The reaction was carried out at 30°C in a reaction mixture consisting of 0.1 M sodium acetate buffer containing (per liter) 20 g of inosine (74.6 mM), 150 g of disodium hydrogen pyrophosphate (200 mM), and 10 g (dry weight) of E. coli JM109(pMPI501) cells.