FIGURE 2.

Effect of ΔΨ on [³H]melibiose uptake. Active transport with RSO vesicles (pH 7.5) containing MelB-ST was carried out in the absence and presence of 20 mm Na⁺ (circle) or Li⁺ (triangle). At the 2-min time point of transport time course, 50 μm valinomycin (Vm, dashed lines), 1 μm nigericin (Ng, dotted lines), or both (dashed and dotted lines) were added into RSO vesicles.