| Popis: |
To improve the specific activity at low temperatures of Ef-EG2 and to maintain thermostability, five mutant enzymes (K273R, N372D, Q387E, N402D, D43R) were produced. The two mutant enzymes (K273R, N402D) lost the cellulase activity. The specific activities of mutant N372D, Q387E, and D43R enzymes were 2.5-fold higher than that of WT enzyme over various temperatures. The denaturation temperatures (Tm) of WT and N372D, Q387E, and D43R enzymes were 55.1 °C, 51.5 °C, 51.2 °C, and 55.6 °C. D43R showed almost the same thermostability as the WT enzyme. The three-dimensional structure of D43R was not significantly different from that of the WT enzyme, but the D43R enzyme lost the ability to bind sodium ions. D43R was introduced the additional electrostatic interaction with Asp55. |
