FIG. 4.

Effects of pH on trehalose phosphorolysis and synthesis of TSase. Error bars are included for the points for which the standard deviation was greater than 10% of the point’s value. (A) For determination of optimum pHs, the trehalose phosphorolysis (○) and synthesis (•) activities at the indicated pHs were measured. The TSase activity at the optimal pH for phosphorolysis was 0.011 U, and TSase synthesized trehalose at 5.39 μmol/h at the optimal pH. (B) For determination of pH resistance, the remaining phosphorolysis (○) and synthesis (•) activities were measured at pH 6.0 after the enzyme had been placed at the indicated pHs at 4°C for 24 h. The remaining synthesis activity was measured at pH 7.0 after the same treatment. A value of 0.011 U is equivalent to 100% activity for phosphorolysis, and a value of 5.39 μmol of trehalose per h is equivalent to 100% activity for synthesis.