TABLE 2.
Summary of kinetic parameters
| kcat | Kma | kcat/Km | |
|---|---|---|---|
| s−1 | mm | s−1 mm−1 | |
| KlAH | |||
| Wild type | 216.8 ± 5.8 (1.0)b,c | 0.88 ± 0.12 (1.0) | 246 ± 40 (1.0) |
| ΔC | 131.6 ± 5.8 (0.61) | 10.9 ± 1.2 (12) | 12.1 ± 1.9 (0.049) |
| G559E/G572E | 141.0 ± 6.0 (0.65) | 12.4 ± 1.3 (14) | 11.4 ± 1.7 (0.046) |
| S177A | NDd | ND | |
| H492A | 164.6 ± 3.4 (0.76) | 0.98 ± 0.08 (1.1) | 168 ± 17 (0.68) |
| Q501A | 191.2 ± 5.2 (0.88) | 1.07 ± 0.11 (1.2) | 179 ± 23 (0.73) |
| K532A | 204.0 ± 3.2 (0.94) | 1.16 ± 0.07 (1.3) | 176 ± 13 (0.72) |
| KlUA | |||
| Wild type | 232 ± 5.3 (1.0) | 0.24 ± 0.04 (1.0) | 967 ± 183 (1.0) |
| H492A | 200 ± 6.4 (0.86) | 0.27 ± 0.06 (1.1) | 740 ± 188 (0.77) |
a Km values are for allophanate (KlAH) and urea (KlUA).
b Numbers in parentheses are ratios to the wild-type values.
c Standard deviations were obtained from fitting the experimental data to the Michaelis-Menten equation.
d ND, not detectable.