FIG. 3.

5′-IMP synthesis using E. coli overproducing wild-type or mutated acid phosphatases. The time course of 5′-IMP synthesis by resting cells of E. coli JM109(pMPI501) (thin lines), E. coli JM109(pMPI600) (broken lines), and E. coli JM109(pMPI700) (thick lines) was measured. The reaction was carried out at pH 4.0 and 30°C in a reaction mixture consisting of 0.1 M sodium acetate buffer (pH 4.0) containing various concentration of inosine, 150 g of disodium hydrogen pyrophosphate per liter (200 mM), and 10 g (dry weight) of each type of cell per liter. Inosine was added to the reaction mixture at 20 g/liter (74.6 mol/liter) (▴), 40 g/liter (149 mol/liter) (○), and 60 g/liter (224 mol/liter) (●).