Kinetic parameters of the wild-type CYP1A2 and its variant enzymes for ethoxyresorufin O-deethylation Values shown are the mean ± S.D. of three to four independent experiments. Km and Vmax values were determined by the Lineweaver-Burk plots.
Amino Acid Alteration | Km | Vmax | Vmax/Km |
|---|---|---|---|
| μM | pmol/pmol 1A2/min | ||
| Wild type | 0.62 ± 0.14 | 0.032 ± 0.008 | 0.051 ± 0.003 |
| T83M | 0.56 ± 0.08 | 0.023 ± 0.015 | 0.039 ± 0.022 |
| E168Q | 0.33 ± 0.04* | 0.010 ± 0.005 | 0.030 ± 0.011 |
| F186L | 0.17 ± 0.08*** | 0.002 ± 0.001* | 0.010 ± 0.001* |
| S212C | 0.96 ± 0.15** | 0.025 ± 0.015 | 0.021 ± 0.012 |
| G299A | 0.64 ± 0.10 | 0.030 ± 0.014 | 0.046 ± 0.017 |
| T438I | 0.57 ± 0.05 | 0.032 ± 0.014 | 0.056 ± 0.021 |
Asterisks represent degree of statistical differences between the wild type according to one-way analysis of variance with a Tukey's post hoc test: *p < 0.05; **p < 0.01; and ***p < 0.001.