Enzyme kinetic parameters and RAF values of ES glucuronidation based on ES-3-G formation in the presence of 2% BSA
The unbound fraction in incubation (ES) = 0.04. The Vmax and KM values in HLM and hrUGT1A1 were calculated from eq. 3. The Vmax and KM values in HIM and HKM were calculated from eq. 2.
| Parameter | HLM | HIM | HKM | hrUGT1A1 |
|---|---|---|---|---|
| Vmax (pmol/min per milligram) | 1522 ± 93 | 7095 ± 130 | 30.6 ± 2.6 | 2082 ± 45 |
| KM (µM) | 147 ± 22 | 31.0 ± 1.4 | 18.7 ± 5.0 | 137 ± 8 |
| h | 1.61 ± 0.26 | N.A. | N.A. | 1.84 ± 0.13 |
| CLint (µl/min per milligram) | 5.3 | 229 | 1.6 | 7.7 |
| CLint,u (µl/min per milligram) | 134 | 5720 | 41 | 192 |
| RAF | 0.7 | 30 | 0.22 | N.A. |
h, Hill coefficient; N.A., not applicable.