Fig. 10.

Substrate efflux (inside positive and acidic). Proteoliposomes, grey smoothed line on black error bars; liposome controls, black smoothed line on grey error bars. Experiments were performed in the presence of (a) $(\mathrm{\Delta }{\bar{\mu }}_H^{+})$, (b) ΔpH only, (c) ΔΨ only or (d) in the absence of any energetic gradient. All traces are mean ± range of at least two replicates after subtracting relevant control experiments absent substrate.