Table 2 Summarize of enzyme kinetic parameters for five SULT activities in pooled human Liver S9.

From: LC-MS/MS quantification of sulfotransferases is better than conventional immunogenic methods in determining human liver SULT activities: implication in precision medicine

Isoforms

Kinetic Parameters

nHLS9s-pooled

tHLS9s-pooled

rHLS9-pooled

SULT1A1a

Km (μM)

0.88 ± 0.20

0.82 ± 0.06

2.63 ± 0.16

Vmax (pmol/mg/min)

2004.77 ± 102.28

451.31 ± 6.88

3679.89 ± 67.25

4-Nitrophenyl sulfate

CL (Vmax/Km, μl/mg/min)

2285.46

550.15

1400.78

Kinetic mechanism

M-Mb

M-Mb

M-Mb

SULT1A3

Km (μM)

0.17 ± 0.06

0.83 ± 0.22

0.41 ± 0.09

Vmax (pmol/mg/min)

35.27 ± 2.52

101.66 ± 10.07

38.67 ± 2.32

Dopamine 3-o-sulfate#1

CL (Vmax/Km, μl/mg/min)

201.77

122.12

95.15

Kinetic mechanism

Substrate inhibition

Substrate inhibition

Substrate inhibition

Km (μM)

0.53 ± 0.18

0.95 ± 0.14

0.76 ± 0.19

Vmax (pmol/mg/min)

6.53 ± 0.88

17.88 ± 0.97

6.66 ± 0.56

Dopamine 4-o-sulfate#2

CL (Vmax/Km, μl/mg/min)

12.29

18.88

8.75

Kinetic mechanism

Substrate inhibition

Substrate inhibition

Substrate inhibition

SULT1B1

Km (μM)

2.78 ± 0.19

2.38 ± 0.36

13.18 ± 2.50

Vmax (pmol/mg/min)

14.07 ± 0.22

6.12 ± 0.21

14.38 ± 1.20

Aminphenol-sulfate

CL (Vmax/Km, μl/mg/min)

5.07

2.57

1.09

Kinetic mechanism

M-Mb

M-Mb

M-Mb

SULT1E1

Km (μM)

10.85 ± 1.20

9.33 ± 0.92

8.11 ± 1.63

Vmax (pmol/mg/min)

76.52 ± 3.56

30.21 ± 1.19

44.69 ± 5.30

β-Estradiol 3-sulfate

CL (Vmax/Km, μl/mg/min)

7.05

3.24

5.51

Kinetic mechanism

Biphasic

Biphasic

Biphasic

SULT2A1

Km (μM)

0.73 ± 0.15

0.70 ± 0.12

0.81 ± 0.08

Vmax (pmol/mg/min)

95.14 ± 7.68

45.46 ± 3.44

81.98 ± 1.65

DHEA 3-sulfate

CL (Vmax/Km, μl/mg/min)

129.57

64.56

101.26

Kinetic mechanism

Substrate inhibition

Substrate inhibition

M-Mb

  1. aProbe substrate and its metabolite.
  2. bM-M, Michaelis-Menten.
  3. The isomers #1(Dopamine 3-o-sulfate) and #2(Dopamine 4-o-sulfate) are the two sulfation metabolites.
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