5. Enzymatic properties of MTGase
The pH optimum of MTGase was around 5 to 8. However, even at pH 4 or 9, MTGase still expresses some enzymatic activity. MTGase is thus considered to be stable over a wide pH range. The optimum temperature for enzymatic activity was 50°C, and MTGase fully sustained its activity even at 50°C for 10 min. On the other hand, it lost activity within a few minutes on heating to 70°C. MTGase still expressed activity at 10°C, and still retained some activity at temperatures just above the freezing-point.