3.2.1.63 2.4 7.5 - 136749 3.2.1.63 4.5 8 - 136752 3.2.1.63 5 8 pH 5.0: about 60% of maximal activity, pH 8.0: about 35% of maximal activity 665770 3.2.1.63 5.6 7.5 the enzyme is optimally active at pH 5.6 to 7.5. Some alpha-L-fucosidase activity is retained at pH 9.2, but no significant activity is found at pH 2.6 and 4.5 750713