Table 2.
Characteristics of purified WT and variants
| Enzyme | Specific activity[a] (U/mg) |
t1/2 (min) | Tm (°C) |
|---|---|---|---|
| Wild-type | 214.0 ± 18.7 | 14.6 | 53.4 |
| I31F | 220.3 ± 16.9 | 14.4 | 53.4 |
| T219L | 243.8 ± 23.1 | 48.7 | 58.0 |
| S360A | 230.2 ± 20.4 | 15.7 | 53.5 |
| T263L | 210.0 ± 14.2 | 15.1 | 53.0 |
| Mut4 | 198.7 ± 18.8 | 53.1 | 57.4 |
[a]The values of purified protein represent the means ± S.D. for three independent experiments
The half-lives (t1/2) of enzymes were evaluated by incubating 0.01 mg/mL purified enzymes for 90 min in a water bath at 50 °C and testing their residual activity every 10 min. The Tm values were determined by nano-DSC, and the 0.5 mg/mL of purified enzymes were scanned from 20 to 100 °C by the scan rate at 1 °C/min