Figure 6.

Transport of choline and albitiazolium into P. falciparum saponin-free parasites and substrate competition. (A) Inhibition of 15 µM choline entry into P. falciparum saponin-free parasites by albitiazolium was determined after 10 min of incubation. (B) The initial velocities of choline uptake into P. falciparum saponin-free parasites in the presence of increasing concentrations of albitiazolium are shown as Lineweaver–Burk double-reciprocal plots. (C) Inhibition of 16 µM albitiazolium entry into P. falciparum saponin-free parasites by choline was determined after 10 min of incubation. (D) Lineweaver–Burk representation of albitiazolium entry into saponin-free parasites in the presence of increasing choline concentrations. Inhibitor concentrations were 0, 3, 6, 9 and 12 µM albitiazolium for (B) and 0, 0.8 and 2 mM choline for (D). Experiments were repeated twice.