TABLE 1

Kinetic parameters for the glucuronidation of DHT, t-AND, TAM, and LTG by recombinant UGT1A4

Data are means (S.E.).

SubstrateKmVmaxKsiKinetics ModelR2
μMpmol/min/mg proteinμM
DHT19.6 (2.2)17.1 (0.44)N.A.Michaelis-Menten (eq. 2)0.9404
t-AND23.6 (3.1)114 (7.2)514 (133)Uncompetitive substrate inhibition (eq. 3)0.9755
TAM0.90 (0.14)447 (37)4.6 (0.71)Uncompetitive substrate inhibition (eq. 3)0.9639
LTG1564 (126)1064 (33)N.A.Michaelis-Menten (eq. 2)0.9926
  • N.A., not applicable.