Table 1 Kinetic parameters of UDH from wt and mutants toward substrate glucuronic acid
Mutants | kcat (102s−1) | Km (mM) | kcat/Km (102 s−1 mM−1) | Specific activity (U mg−1) | Relative activity (100%) |
|---|---|---|---|---|---|
WT | 1.61 ± 0.3 | 0.20 ± 0.06 | 8.0 | 85 ± 2.1 | 100.0 ± 3.2 |
A39P | 1.92 ± 0.5 | 0.26 ± 0.03 | 7.3 | 88 ± 3.1 | 103.5 ± 2.6 |
H99Y | 1.79 ± 0.4 | 0.23 ± 0.05 | 7.7 | 93 ± 4.1 | 109.6 ± 3.4 |
H234K | 1.95 ± 0.2 | 0.24 ± 0.03 | 8.1 | 110 ± 3.1 | 129.4 ± 2.9 |
A39P/H99Y | 2.39 ± 0.1 | 0.20 ± 0.04 | 7.2 | 124 ± 2.9 | 146.8 ± 3.2 |
A39P/H234K | 2.95 ± 0.4 | 0.18 ± 0.06 | 8.4 | 140 ± 3.6 | 165.7 ± 3.5 |
H99Y/H234K | 3.18 ± 0.5 | 0.17 ± 0.05 | 8.6 | 149 ± 1.9 | 175.4 ± 2.9 |
A39P/H99Y/H234K | 3.8 ± 0.7 | 0.15 ± 0.03 | 9.1 | 210 ± 3.0 | 247.6 ± 3.5 |