Transport Site/Direction | Vmax | Km | Kd | Vmax/Km | |
---|---|---|---|---|---|
pmol · min–1 · (mg protein)–1 | mM | μl · min–1 · (mg protein)–1 | |||
APa | 331 ± 68 | 0.9 ± 0.2 | 0.036 ± 0.011 | 0.37 | |
BLb | 619 ± 15 | 12.3 ± 0.4 | N.A.c | 0.05 | |
AP to BL transportd | 5.1 ± 0.2 | 0.06 ± 0.03 | 0.067 ± 0.004 | 0.09 |
N.A., not applicable
↵ a Initial AP uptake data (5 min) are presented in Fig. 2B with model fits used to generate kinetic parameter estimates by nonlinear least-squares regression analysis
↵ b BL uptake kinetic parameters were obtained from the concentration dependence of BL uptake in the linear uptake range (30 min) from 0.01 to 5 mM dosing concentrations
↵ c BL uptake data did not support the incorporation of a term for nonsaturable uptake
↵ d AP to BL transport kinetic parameters, Jmax and Kd, transport, were divided by the average protein content in a Caco-2 monolayer (0.2 mg for 1 cm2 Transwell insert) and Jmax was expressed as the maximal velocity, Vmax, for comparison