Table 1.
Enzyme variant | KM (μM)a | Specific activity (μmol min-1 mg-1)a | Catalytic efficiency (μmol min-1 mg-1 μM-1) | Volumetric activity (U l-1)a |
Protein yield (mg l-1)b |
Improvement factor |
CotA | 6.5 ± 0.2 | 16.0 ± 0.2 | 2.46 | 410 ± 10 | 26 | 1 |
D500G | 9.5 ± 0.2 | 11.1 ± 0.1 | 1.17 | 2200 ± 200 | 199 | 7.8 |
K316N | 10.0 ± 0.3 | 14.0 ± 0.2 | 1.40 | 1100 ± 100 | 79 | 3.1 |
K316N/D500G | 8.4 ± 0.2 | 11.7 ± 0.2 | 1.39 | 3400 ± 100 | 291 | 11.4 |
a Determined using ABTS as substrate in 0.1 M citrate/phosphate buffer, pH 4.0. Each value was calculated from three independent experiments.
b Calculated on the basis of volumetric activity and specific activity of each laccase variant.