fig4

Figure 4. ABCB1 ATPase activity vs. allocrite concentration curves. ATPase activity measured in inside-out plasma membrane vesicles from NIH-MDR1-G185 cells[25]. Data are fitted to the two-site binding model by Litman et al.[96]. Tariquidar (diamonds); OC144 093 (circles), cyclosporine A (stars), DDM (squares), verapamil (triangles). Tariquidar, OC144 093, and verapamil inhibit as dimers. DDM[79] and cyclosporine A (see Ref.[79], Supplementary Table 3 therein) most likely inhibit as monomers due to their unfavorable q = /
values (see below).