2.7.7.38 6.5 9 about half-maximal activity at pH 7.0 and pH 8.4 645226 2.7.7.38 7.5 10.2 about half-maximal activity at pH 7.5 and about 80% of maximal activity at pH 10.2 in Tris-acetate buffer 645227 2.7.7.38 7.5 10.5 about half-maximal activity at pH 7.5 and about 60% of maximal activity at pH 10.5 in glycine-NaOH buffer 645227 2.7.7.38 8.5 9.5 - 723536