TABLE 1

Analysis of the steady-state kinetics of 7BQ debenzylation by CYP3A4 in terms of the three models shown in Schemes 1 , 2A, and 2B

The equations describing the models (eqs. 1–3 under Materials and Methods) were fitted to the experimental data shown in Fig. 2. The parameters are defined in the schemes and under Materials and Methods. Statistical comparison of the fits with the data: eq. 2 versus eq. 1, P = 0.02; eq. 3 versus eq. 1, P = 1.7 × 10–7; and eq. 3 versus eq. 2, P = 0.005.


Parameter

Scheme 1 (eq. 1)

Scheme 2A (eq. 2)

Scheme 2B (eq. 3)
Vmax (a.u.) 0.85 ± 0.07 0.167 ± 0.002 0.165 ± 0.005
Ks1 (μM) 473 ± 50 267 ± 17 513 ± 77
Ks2 (μM) 4600 ± 1900 107 ± 13 195 ± 32
Ks3 (μM) 739 ± 40 458 ± 103
α 0.004 ± 0.001 0.063 ± 0.005 0.017 ± 0.003
β 0.10 ± 0.01 0.11 ± 0.04
χ2
5 × 10-3
2 × 10-3
1 × 10-4
  • a.u., arbitrary units.