Kinetic constants of BCHE and mutants with (−)-cocaine
| (−)-Cocaine | ||
|---|---|---|
| Enzyme | KM | kcat |
| μM | min −1 | |
| Wild-type | 4.5 ± 0.3 | 4.1 ± 0.4 |
| Tyr332Ala | 245 ± 64 | 109.5 ± 0.7 |
| Ala328Trp | 3.1 ± 0.1 | 50 ± 0.6 |
| Ala328Trp/Tyr332Ala | 18 ± 2 | 154 ± 14 |
Hydrolysis of (−)-cocaine was determined radiometrically. Data were fitted to the Michaelis-Menten equation by nonlinear regression;V max was divided by titrated enzyme concentrations to calculate k cat.