Comparison of observed and model-predicted rates of AdiC-mediated ligand uptakes into lipid vesicles. (A–F) The predicted values by the model shown in Fig. S6 (A–C) or those by the model in Fig. S7 (D–F) are compared with corresponding observed values for a given experimental condition (Tsai et al., 2012). Net ligand uptake rates are plotted against the ligand concentration: Agm²⁺ via AdiC in the outside-out (A and D) or inside-out (B and E) orientation and Arg⁺ via AdiC in the inside-out orientation (C and F; see Fig. S9 for the comparison and comments regarding the outside-out orientation). The experimental data are plotted as mean ± SEM, and the predicted values of the alternative models shown in Figs. S6 and S7 by means of Monte Carlo simulations or calculations are plotted as mean ± σ calculated from the corresponding confidence interval. The observed data set is represented by closed dark blue circles, the simulated set of the model by closed red circles, and the five calculated sets, one for each transition, by five of practically concentric open circles. The curves, which are superimposed on the symbols that represent the calculated values, correspond to the fits of the Michaelis–Menten equation. All fit parameters of calculated values are presented in Table S13, along with those reported by Tsai et al. (2012). All calculations were performed as described in the supplemental text at the end of the PDF.