Fig. 3. F-dexa–binding isotherm. (A) Membrane-bound F-dexa S(₃) as a function of the F-dexa concentration in the binding medium for the average of measurements for each particular concentration (± s.d.). (B) Calculated molar concentrations of bound F-dexa for individual measurements () and for the average of measurements () for each particular concentration. Data were fitted to a Hill equation with variable slope (solid line), which yields a B_max of 230±10 nM, an apparent K_d of 180±10 nM and a Hill coefficient of 2.1±0.2. Insert shows the average of measurements () for each particular concentration (± s.d.) on a linear F-dexa concentration scale. (C) Scatchard plot of transformed data (individual measurements () and for the average of measurements () together with the transformed nonlinear fit (solid line).