FIG 4.

Effects of temperature and pH on the activity and stability of rLamC and rLamC-ΔN. (a) To determine the optimal temperature, the recombinant enzymes were incubated in phosphate buffer (20 mM; pH 7.0) with 10 mg/ml laminarin substrate for 20 min at various temperatures (30 to 70°C). (b) Thermostability of rLamC and rLamC-ΔN. The residual activity was measured under optimal conditions after incubation of the enzyme at the indicated temperatures (30 to 70°C) for 30 min. (c) To determine the optimal pH, the recombinant enzymes were incubated with 10 mg/ml laminarin substrate for 20 min at 50°C in buffers of various pH values (4.0 to 10.0). (d) Stability of rLamC and rLamC-ΔN at different pH values. The residual enzyme activity was measured under optimal conditions after incubation of the purified enzyme with buffers with various pH values at 4°C for 24 h.