Table 2.
Catalytic properties of wild‐type and mutant GAs at pH 4.5, using maltose as substrate.
| GA form | Specific activitya (IU mg−1) | kcatc (s−1) | Km (mM) | kcat/Km (s−1 mM−1) |
|---|---|---|---|---|
| Wild type | 13.9 ± 0.2b | 7.3 ± 0.1d | 0.7 ± 0.0 | 10 |
| RE5 | 14.7 ± 1.1 | 7.7 ± 0.3 | 1.4 ± 0.1 | 5.5 |
| RE5+E408K | 15.4 ± 0.6 | 8.1 ± 0.2 | 1.4 ± 0.1 | 5.8 |
| CR1‐1 | 13.8 ± 0.4 | 6.4 ± 0.1 | 0.8 ± 0.0 | 7.7 |
| RE15 | 21.3 ± 0.7 | 11.7 ± 0.4 | 1.0 ± 0.1 | 12 |
| SRE15 | 23.1 ± 1.9 | 12.9 ± 0.6 | 1.8 ± 0.2 | 8.0 |
| SRE15+V59A | 12.2 ± 0.7 | 6.5 ± 0.2 | 1.5 ± 0.0 | 4.3 |
| CR2‐1 | 13.9 ± 0.3 | 7.5 ± 0.1 | 1.1 ± 0.0 | 6.8 |
a.
Measured at 50°C.
b.
Standard deviation from six assays.
c.
Measured at 35°C.
d.
Standard error from duplicate assays.