Figure 4. Movement of Tariquidar when bound to P-glycoprotein.

Tariquidar was docked to P-glycoprotein as described in Methods and Results and was found to preferentially bind to three different sites within P-gp. Panel A shows the three tariquidar docking sites in van der Waal’s spheres with site 1 in yellow, site 2 in purple and site 3 in red. Targeted molecular dynamics simulations were performed with tariquidar bound at each of these sites (site 1, 2 and 3, with six replicate simulations for each site) and the average movement of the center of mass of tariquidar is shown in Panel B. Movement was calculated as in Figure 3. Error bars represent one standard error of the mean. Panel C shows the positions of tariquidar at the end of representative simulations with the same color coding as in Panel A.