Kinetics of catechol glucuronidation by the rat liver recombinant UGT1A6 and UGT2B1
| Substrates | UGT1A6 | UGT2B1 | ||||
|---|---|---|---|---|---|---|
| Km | Vmax | Vmax/Km | Km | Vmax | Vmax/Km | |
| Catechol | 654.5 | 1.2 | 1.8 | |||
| 4-Nitrocatechol | 988.8 | 2.2 | 2.2 | 1929 | 0.7 | 0.4 |
| 3-Fluorocatechol | 359.5 | 1.3 | 3.6 | 1191 | 0.7 | 0.6 |
| 4-Methylcatechol | 1250 | 12.9 | 10.3 | 2226 | 0.9 | 0.4 |
| 4-tert-Butyl-5-metoxycatechol | 122.6 | 0.2 | 1.7 | 128.1 | 1.4 | 11.4 |
| Tetrachlorocatechol | 100.4 | 1.9 | 19.5 | 117.5 | 1.5 | 13.0 |
| 3,5-Dinitrocatechol | 1345 | 0.7 | 0.5 | |||
| 2,3 Dihydroxybenzaldehyde | 5112 | 1.5 | 0.3 | |||
| Methylgallate | 963.1 | 3.7 | 3.8 | 1795 | 0.9 | 0.5 |
| Octylgallate | 57.3 | 0.9 | 15.8 | |||
| Dobutamine 1 | 1037 | 0.1 | 0.1 | |||
| Dobutamine 2 | 537.8 | 0.5 | 0.9 | |||
| Tyrphostine A23 | 1437 | 0.8 | 0.6 | |||
Km, Vmax, andVmax/Km were expressed as micromolar concentration, nanomoles per minute per milligram of protein, and microliters per minute per milligram of protein, respectively. For dobutamine, two glucuronides (dobutamine 1 and 2) were formed and separated by HPLC.