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. Author manuscript; available in PMC: 2018 Dec 4.
Published in final edited form as: Pharmacogenet Genomics. 2012 Aug;22(8):561–576. doi: 10.1097/FPC.0b013e328354026b

Table 1.

Kinetic analysis of UGTs active against CLZ in vitro.

CLZ-5-N-glucuronide CLZ-N+-glucuronide dmCLZ-5-N-glucuronide
UGT variant Vmax
(pmol·min−1·μg−1)*
KM
(μM)
Vmax/KM
(nl·min−1·μg−1)*
Vmax
(pmol·min−1·μg−1)*
KM
(μM)
Vmax/KM
(nl·min−1·μg−1)*
Vmax
(pmol·min−1·μg−1)*
KM
(μM)
Vmax/KM
(nl·min−1·μg−1)*
UGT1A1 nd nd nd 0.86 ± 0.02a,b 53 ± 2a,b 17 ± 0.6a no activity detected
UGT1A424Pro/48Leu 42 ± 3 173 ± 19 246 ± 31 6.3 ± 0.6 768 ± 62 8.2 ± 0.8 10 ± 0.7 379 ± 46 28 ± 2.8
UGT1A424Thr/48Leu 33 ± 2b,c 167 ± 19d 196 ± 14b,c 3.6 ± 0.1a,b 459 ± 23e 7.8 ± 0.3b 6.4 ± 0.9b,e 440 ± 45b 15 ± 1.5b,e
UGT1A424Pro/48Val 93 ± 9a 73 ± 8e 1284 ± 77a 7.6 ± 0.1c 481 ± 9e 16 ± 0.2a 17 ± 1.3d 173 ± 22e 96 ± 8.0a
*

Michaelis-Menten kinetic values represent per μg UGT protein. nd = not detected, below the limits of UPLC detection.

a

p<0.0001,

b

p<0.0001,

c

p<0.05,

d

p<0.002 versus corresponding value for UGT1A424Pro/48Val-over-expressing cell homogenate, calculated using the Students t-test (two-sided).

e

p<0.001 versus corresponding value for UGT1A424Pro/48Leu-over-expressing cell homogenate, calculated using the Students t-test (two-sided).