Table 7 Kinetic parameters of zidovudine O-glucuronidation by single expressed UGT2B7*NHA and double expressed UGT1A9*NCFP/2B7*NHA systems.

From: Inter-isoform Hetero-dimerization of Human UDP-Glucuronosyltransferases (UGTs) 1A1, 1A9 and 2B7 and Impacts on Glucuronidation Activity

2B7*N or 1A9*N/2B7*N

Km (μM)

Vmax (pmol/min/unit)

CLint (nL/min/unit)

% of 2B7*NHA

2B7*1HA

508.2 ± 18.59

37.64 ± 0.50

74.06

100

1A9*1CFP/2B7*1HA

469.1 ± 16.85

75.96 ± 0.97***

161.93***

218.6

1A9*2CFP/2B7*1HA

638.0 ± 26.27**

27.79 ± 0.45***

43.56***

58.8

1A9*3CFP/2B7*1HA

539.8 ± 25.84

35.30 ± 0.63*

66.01**

88.3

1A9*5CFP/2B7*1HA

606.4 ± 34.71*

17.74 ± 0.39***

29.25***

39.5

2B7*71S HA

533.5 ± 25.61

68.80 ± 1.23

128.96

100

1A9*1CFP/2B7*71S HA

502.7 ± 30.23

103.7 ± 2.27***

206.29***

160.0

1A9*2CFP/2B7*71S HA

751.3 ± 33.11**

50.38 ± 0.95***

67.06***

52.0

1A9*3CFP/2B7*71S 1HA

626.8 ± 26.30*

37.94 ± 0.63***

60.53***

38.2

1A9*5CFP/2B7*71S HA

502.4 ± 28.33

15.83 ± 0.32***

31.51***

19.9

2B7*2HA

570.1 ± 34.18

24.88 ± 0.57

43.64

100

1A9*1CFP/2B7*2HA

381.1 ± 17.54**

76.63 ± 1.16***

201.08***

460.7

1A9*2CFP/2B7*2HA

588.7 ± 25.32

15.04 ± 0.25***

25.55***

58.5

1A9*3CFP/2B7*2HA

674.8 ± 31.06*

32.26 ± 0.60***

47.81*

109.5

1A9*5CFP/2B7*2HA

783.8 ± 28.45**

9.566 ± 0.15***

12.20***

28.0

  1. Asterisks indicate statistically significant differences compared with UGT2B7*NHA single expression systems (***P < 0.0001, **P < 0.005, *P < 0.05). Data are mean ± SD of three independent determinations.
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