TABLE 2.
Dibenzylfluorescein O-debenzylation activities
| BTC3A4_PORa | kcat | Km | R2 | kcat/Km |
|---|---|---|---|---|
| fluorescein-formed pmol · min−1 · pmol CYP3A4−1 | μM | % WT | ||
| Null | —b | — | — | — |
| WT | 0.43 ± 0.03 | 1.37 ± 0.22 | 0.97 | 0.32 (100) |
| P228L | 0.23 ± 0.01 | 0.78 ± 0.14 | 0.95 | 0.30 (95) |
| M263V | 0.28 ± 0.02 | 0.76 ± 0.12 | 0.95 | 0.38 (119) |
| A287P | 0.25 ± 0.01 | 0.84 ± 0.10 | 0.97 | 0.29 (93) |
| G413S | 0.33 ± 0.02 | 0.89 ± 0.15 | 0.96 | 0.37 (115) |
| Q153R | 0.80 ± 0.04 | 4.24 ± 0.45 | 0.99 | 0.19 (60) |
| R457H | 0.052 ± 0.001 | 1.70 ± 0.07 | 0.99 | 0.03 (10) |
| G539R | 0.059 ± 0.002 | 0.62 ± 0.06 | 0.98 | 0.10 (30) |
| Y181D | — | — | — | — |
| Y459H | — | — | — | — |
| V492E | — | — | — | — |
| L565P | — | — | — | — |
| R616X | — | — | — | — |
| Human liver microsomes | 0.47 ± 0.04 | 1.36 ± 0.17 | 0.99 | 0.34 (108) |
a
Velocity parameters obtained using a DBF gradient up to 5 μM, except for human liver microsomes for which a gradient up to 1.25 μM was applied to prevent interference with DBF metabolism by CYP2C8 (Ghosal et al., 2003) and for CYPOR variant Q153R for which a gradient up to 10 μM was applied.
b
—, not measurable.