... activity on glucose. BLXI activity in the presence of Mn2þ and Mg2þreached only 6% and 15%, respectively, of the activityin the presence of Co2þ(Fig. 4A). Co2þ,Mn2þ, and Mg2þactivation ... 0.05, 0.5, and 2.5 mg·mL21enzyme, respectively) indicate that BLXIinactivation is slightly dependent on concentration, withBLXI stability increasing with enzyme concentration. At 0.5 and 2.5 ... fructose, respectively. One unit of isomerase activity is defined as the amount of enzyme thatproduces 1 mmol of product per min under the assayconditions.Activation of apo-BLXI by metalsTo examine...