Estimated kinetic parameters for the formation of nirvanol from nirvanol-free (S)-MP (0.5–200 μM), in the presence or absence of sulfaphenazole (25 μM), in pooled HLMs (HL2, HL8, and HL9)
Incubation with | Kinetics of Nirvanol Formation | |||||
---|---|---|---|---|---|---|
KM,1 | Vmax,1 | Vmax,/KM,1 | KM,2 | Vmax,2 | Vmax,2/KM,2 | |
μM | pmol/min/mg protein | μM | pmol/min/mg protein | |||
(S)-MP alone | 174.1 | 170.5 | 0.98 | 1,910 | 3,980 | 2.1 |
(S)-MP + sulfaphenazole | 2,706 | 22,690 | 8.4 |
KM,1 and Vmax,1refer to Michaelis-Menten parameters for the high-affinity component, whereas KM,2 and Vmax,2 refer to the low-affinity component. Values are means of estimates from nonlinear least-squares regression analysis, performed using WINNONLIN (seeMaterials and Methods).