FIG. 8.

PEP-dependent sugar phosphorylation activities of peaks 1 (white bars) and 2 (black bars) at different pH values from 4 to 10 with methyl-α-glucoside (A) or 2-deoxyglucose (B) as the sugar substrate. The assays were conducted as outlined in Materials and Methods, with PEP at 2.5 mM and the ¹⁴C-labeled sugar concentration at 10 μM. The enzyme preparations used were from strain 301, and a 4-h HSS of an extract from strain AD90 was used as a source of the soluble PTS energy-coupling enzymes. The experiments were conducted three times, and the standard deviation values are indicated by the vertical bars.