Table 4

Glucuronidating activities in UGT2B1- or UGT2B12-overexpressing HK293 cell lines

Overexpressed UGT IsozymeAglycone4-aLevels of Aglycone-Gluc Formation
nmol/mg protein
UGT2B1clofibric acid4-b 3.1  ± 0.30
NNAL4-b 0.62  ± 0.38
UGT2B124-NP4-b 0.20  ± 0.02
NNAL4-c no activity
  • 4-a Aglycone concentrations utilized for in vitro glucuronidation assays were as follows: clofibric acid, 12 μM; NNAL, 500 μM; 4-NP, 1680 μM. Assays were performed at 37°C for 40 min using 2 mM [14C]UDPGA (0.5 μCi/reaction) as described inMaterials and Methods.

  • 4-b Glucuronidation activity assayed using 250 μg of cell homogenate protein.

  • 4-c Glucuronidation activity assayed using 3.9 mg of cell homogenate protein.