TABLE 2

Kinetic parameters for the metabolism of TAM to α-hydroxy-TAM, 4′-hydroxy-TAM, 3-hydroxy-TAM, and M-I in HLMs Apparent formation rates (pmol/min/mg of protein) of metabolites against TAM concentrations were fit to a single-site binding equation (4′-hydroxy-TAM, M-I and 3-hydroxy-TAM) or a substrate inhibition equation (α-hydroxy-TAM) as detailed under Data Analysis.


Metabolites

HG112

HG23

HG06
Vmax
Km
Vmax/Km
Vmax
Km
Vmax/Km
Vmax
Km
Vmax/Km
M-I 11.9 5.2 2.3 2.9 4.5 0.6 7.5 6.5 1.2
α-Hydroxy-TAM 6.5 1.5 4.5 NE NE NE NE NE NE
3-Hydroxy-TAM 2.1 4.5 0.5 0.8 5.3 0.2 3.0 5.2 0.6
4′-Hydroxy-TAM
5.0
4.0
1.3
1.9
22.2
0.1
NE
NE
NE
  • Vmax, pmol/min/mg of protein; Km, μM; and Vmax/Km, μl/min/mg of protein; NE, not estimated.