3.4.19.3 5 8 about 40% of maximal activity at pH 5.0 and at pH 8.0 95298 3.4.19.3 5.5 10 pH 5.5: about 50% of maximal activity, pH 10.0: about 65% of maximal activity 95290 3.4.19.3 6 8.5 pH 6.5: about 45% of maximal activity, pH 8.5: about 25% of maximal activity 95299 3.4.19.3 6 9 pH 6.0: about 30% of maximal activity, pH 9.0: about 40% of maximal activity 667525 3.4.19.3 6 9 pH 6.0: about 75% of maximal activity, pH 9.0: about 70% of maximal activity, hydrolysis of pyroglutamyl-4-methylcoumaryl-7-amide 653759 3.4.19.3 7 9.5 50% of maximal activity at pH 7 and at pH 9.5 95301 3.4.19.3 7.5 10 activity dropping off sharply outside this pH range 681896