FIG 3.

Effects of temperature and pH on the activity and stability of CoMA. (A) Determination of the optimal pH. Assays were carried out by the addition of 0.3 μg of purified CoMA to 5 mg/ml soluble starch substrate at 50°C for 10 min in buffers of various pH values (pH 2.0 to 11.0). (B) Determination of the optimal temperature. The activity was measured by the addition of 0.3 μg of purified CoMA to 20 mM Tris-HCl (pH 7.0) buffer containing 5 mg/ml soluble starch substrate at 20 to 70°C for 10 min. (C) Stability of CoMA at different pH values. The residual enzyme activity was measured under optimal conditions after incubation of the 0.3 μg of purified enzyme with each buffer (various pH values) at 4°C for 24 h. (D) Thermostability of CoMA. The residual activity was measured under optimal conditions after incubation of 0.3 μg of purified enzyme at the indicated temperatures for up to 60 min. Mean values and standard deviations from three independent experiments are shown.