Figure 1.

(a) Structures of the studied compounds. (b) Chloride efflux promoted by compound MM3 (5 µM, black; 0.5 µM, red; 0.25 µM, blue; 0.05 µM, magenta; 0.005 µM, green) in unilamellar 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) vesicles. Vesicles containing NaCl (451 mM NaCl and 20 mM phosphate buffer, pH 7.2) were immersed in Na₂SO₄ (150 mM Na₂SO₄, 40 mM NaHCO₃ and 20 mM phosphate buffer, pH 7.2). Each trace represents the average of at least three different experiments. (c) Chloride efflux promoted by compound MM34 (5 µM, black; 0.5 µM, red; 0.25 µM, blue; 0.05 µM, magenta; 0.025 µM, green) in unilamellar POPC vesicles. The experimental conditions are identical to those reported for MM3. (d) Transport activity plotted againts the concentration for both compounds, in model liposomes, was fitted with the Hill equation, represented as a continuous line.