TABLE 4

Enzyme kinetic parameters of sulfation in the incubations with O-demethyl apixaban in human liver S9, human cDNA-expressed SULT1A1 and SULT1A2

Substrate concentration-dependent formation of O-demethyl apixaban sulfate was evaluated in triplicate with human liver S9, human cDNA-expressed SULT1A1 and SULT1A2. Substrate concentrations ranged from 0.01 to 300 μM, and samples were incubated at 37°C for 30 min. Details of the incubation and sample analyses are described under Materials and Methods.




Km (n = 3)

Vmax (n = 3)

CLint (Vmax/Km; n = 3)
μM; mean ± S.D. nmol/min/mg protein; mean ± S.D. ml/min/mg protein; mean ± S.D.
Human liver S9 41.4 ± 24.7 7.0 ± 0.8 0.2 ± 0.08
SULT1A1 36.8 ± 28.2 370.0 ± 150.0 13.0 ± 6.0
SULT1A2
70.8 ± 53.3
70.0 ± 18.0
1.2 ± 0.7