Table 1

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 withKinetics of Nirvanol Formation
KM,1Vmax,1Vmax,/KM,1KM,2Vmax,2Vmax,2/KM,2
μM pmol/min/mg protein μM pmol/min/mg protein
(S)-MP alone174.1170.50.981,9103,9802.1
(S)-MP + sulfaphenazole2,70622,6908.4
  • 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).