TABLE 2

Kinetic parameters for SN-38 glucuronidation by wild-type and D256N variant human UGT1A9s

The results were expressed as the mean ± S.D. from three independent transfection experiments. Vmax values were normalized by the relative protein expression level, 0.76 ± 0.05 for the D256N variant.

UGT1A9
Apparent Km
Vmax
Vmax/Km
Normalized Vmax
Normalized Vmax/Km
μM pmol / min / mg protein nl / min / mg protein pmol / min / mg protein nl / min / mg protein
Wild-type 19.3 ± 0.7 2.94 ± 0.22 152 ± 10 2.95 ± 0.29 153 ± 20
D256N
44.4 ± 6.9*
0.24 ± 0.01*
5.4 ± 0.7*
0.31 ± 0.01*
7.1 ± 1.4*

  • ↵* Signifies data significantly different from that of wild-type at the level of p < 0.01.