Enzymatic Activity Analysis and Catalytic Essential Residues Identification of Brucella abortus Malate Dehydrogenase

Figure 5

The thermostability of His-MDH.

(a)  The optimal reaction temperature is at 40°C

(b) 1 μg of His-MDH was preincubated at 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, or 70°C, respectively, for 1 h for the assay. The results showed that His-MDH retained over 85% of the initial activity when preincubated at 30°C to 45°C. However, preincubation at 55°C caused His-MDH to lose 80% activity. The experiments were performed in triplicate, and the bars represent standard deviations