Comparison of enzyme activities of the native and N-terminal 6xHistagged Fe supreoxide dismutase from Streptomyces subrutilus P5
2016
Park, J.H., Dankook University, Cheonan, Republic of Korea | Kim, J.H., Dankook University, Cheonan, Republic of Korea
This study was carried out to analyze the differences in enzyme activity and stability between the native Fe superoxide dismutase (FeSOD) and the 6xHis-tagged superoxide dismutase (6xHis-FeSOD) of Streptomyces subrutilus P5. The optimum pHs for both native FeSOD and 6xHis-FeSOD were 7, while the pH range of the activity was narrower for the 6xHis-FeSOD. The native FeSOD was stable at pH 4 - 9, but the 6xHis-FeSOD lost its stability at pH greater than 9. The temperatures of the optimum activities were same for both types of enzymes. However, the heat stability of the 6xHis-FeSOD was clearly decreased; even at 20℃ the enzyme lost the activity after 360 min. In contrast, the native FeSOD was stable after 720 min at below 40℃. H2O2 inhibition was occurred already at 0.5 mM for the 6xHis-tagged enzyme. Therefore, from the results that the 6xHis-FeSOD retained the enzyme activity at pH 6 - 7 and 20 - 40℃, it can be assumed that the protein structure became destabilized under different storage conditions and sensitive to the enzyme inhibitor.
显示更多 [+] 显示较少 [-]