TABLE 3. Comparison of kinetic constants for HPO mutants.
Constants were calculated by nonlinear regression fits to the Michaelis-Menten equation.
| Enzyme | Substrate | Product | Km | kcat | kcat/Km |
|---|---|---|---|---|---|
| µm | S−1 | ||||
| HPOa | PSD | Solavetivol | 14.0 ± 1.9 | 2.1 ± 0.10 | 0.15 |
| Valencene | β-Nootkatol | 7.4 ± 1.2 | 1.9 ± 0.07 | 0.26 | |
| EA | 2β-(OH)EA | 3.3 ± 0.3 | 0.2 ± 0.01 | 0.06 | |
| HPO, V482I | PSD | Solavetivol | 6.2 ± 0.8 | 3.8 ± 0.17 | 0.61 |
| Valencene | β-Nootkatol | 6.9 ± 1.0 | 5.1 ± 0.23 | 0.74 | |
| EA | 2β-(OH)EA | 17.9 ± 2.5 | 1.4 ± 0.10 | 0.08 | |
| HPO, V480I/A484I | PSD | Solavetivol | 8.4 ± 0.8 | 12.7 ± 0.43 | 1.51 |
| Valencene | β-Nootkatol | 19.2 ± 1.3 | 5.7 ± 0.18 | 0.30 | |
| EA | 2β-(OH)EA | 2.5 ± 0.2 | 0.7 ± 0.01 | 0.28 | |
| HPO, V482I/A484I | PSD | Solavetivol | 13.0 ± 0.9 | 20.7 ± 0.64 | 1.59 |
| Valencene | β-Nootkatol | 12.1 ± 1.9 | 15.9 ± 0.95 | 1.31 | |
| EA | 2β-(OH)EA | 4.3 ± 0.9 | 2.8 ± 0.14 | 0.65 | |
a
Data are from Table I; PSD, premnaspirodiene; EA, 5-epi-aristolochene.