Table 1.
Kinetic and substrate binding parameters of human dUTPase mutants
| kcat (s−1) | kH (s−1) | kP (s−1) | KM (µM) | Kd,dUPNPP (µM) | kcat/KM (M−1*s−1) | |
|---|---|---|---|---|---|---|
| hDUTWT | 5.8 ± 0.5 | 8.0 ± 2 | 1.0 ± 0.4 | 2.0 ± 1 | 5.8*106 | |
| hDUTF158W | 6.8 ± 2a | 5.5 ± 2.5a | 6.5 ± 0.1a | 3.6 ± 2a | 1.5 ± 1 | 1.9*106 |
| hDUTF158A | 0.32 ± 0.1 | 0.13 ± 0.01 | 0.25 ± 0.05 | 5.2 ± 0.4 | 4.8 ± 2 | 6.2*104 |
kH: observed rate constant of the hydrolysis step.
kP: observed rate constant of proton release.
Errors represent standard deviations of three independent measurements. In case fitting was carried out to data points with appended standard deviations, error propagation was calculated by the fitting software.
aToth et al. (23).