Comparison of kinetics of glucuronide formation in HK293 cells stably expressing UGT1A8 and UGT1A10
| Substrates | Human UGT1A8 | Human UGT1A10 | ||||
|---|---|---|---|---|---|---|
| ApparentKm | Vmax | Vmax/Km | ApparentKm | Vmax | Vmax/Km | |
| μM | pmol/min/mg protein | μl/min/mg protein × 100 | μM | pmol/min/mg protein | μl/min/mg protein × 100 | |
| Scopoletin | 225 | 24,405 | 10,847 | 540 | 1,011 | 187 |
| Alizarin | 158 | 7,850 | 4,968 | 128 | 905 | 707 |
| Naringenin | 129 | 4,248 | 3,293 | |||
| Apigenin | 36 | 3,145 | 8,736 | 23 | 220 | 956 |
| Propofol | 412 | 3,820 | 927 | |||
| 1-Naphthol | 112 | 4,277 | 3,819 | |||
| Eugenol | 325 | 1,727 | 531 | 78 | 226 | 290 |
| Naloxone | 450 | 121 | 27 | |||
| Naltrexone | 1,550 | 495 | 32 | |||
The apparent Km and Vmax values for aglycones were determined using 2.0 mM UDP-glucuronic acid. Assays were conducted using the pH optimum for each substrate, and linear product formation with respect to time and protein concentration. Values are the results obtained using two different experiments.