Table 8. Kinetic parameters for morphine-3-glucuronide and morphine-6-glucuronide catalyzed by UGT1A9*5-UGT2B7*N double recombinant allozymes.
| UGT1A9*5 -UGT2B7*N |
Km (μmol/L) |
Vmax (pmol·min−1·mg−1 protein) |
CLint (μL·min−1·mg−1 protein) |
CLint (M3G)/ CLint (M6G) | % of 2B7*1HA |
||||
|---|---|---|---|---|---|---|---|---|---|
| M3G | M6G | M3G | M6G | M3G | M6G | M3G | M6G | ||
| UGT1A9*5-CFP -UGT2B7*1-HA | 26.03±4.453 | 23.55±4.242** | 2020±102.9** | 1590±82.29** | 77.60** | 67.52** | 1.149 | 734.2 | 1147 |
| UGT1A9*5-CFP -UGT2B7*71S-HA | 29.36±3.938 | 24.47±4.555** | 2095±87.31** | 1645±89.21** | 71.36** | 67.23** | 1.061 | 675.1 | 1142 |
| UGT1A9*5-CFP -UGT2B7*2-HA | 30.77±6.448 | 27.41±4.998** | 2245±148.6** | 1796±99.32** | 72.96** | 65.52** | 1.114 | 690.3 | 1113 |
| UGT1A9*5-CFP -UGT2B7*5-HA | 22.97±5.130* | 17.27±4.430** | 2108±134.1** | 1426±93.92** | 91.77** | 82.57** | 1.111 | 868.2 | 1403 |
Kinetics analysis of UGT1A9*5-UGT2B7*N double recombinant allozymes mediate the glucuronide metabolism of morphine. Data are the mean±SD of three independent determinations, the asterisks indicate differences that are statistically significant compared to 2B7*1HA (**P<0.01; *P<0.05).