Figure 6.
Q8 does not affect ProP activity in proteoliposomes. ProP-His6–containing PRLs were fused with E. coli lipid liposomes (open circles) or Q8-supplemented E. coli lipid liposomes (for a final Q8 concentration of 1% (w/w)) (closed circles), initial rates of proline uptake were measured, and data were analyzed as described under “Experimental procedures.” The osmolalities of the assay media were adjusted with sorbitol (0–0.48 m). For each preparation, data from two replicate experiments were fit to Equation 1, the uptake activities were normalized on the resulting Amax values, and the data were combined and again fit to Equation 1. The resulting regression lines are shown in the figure, and the osmolality response parameters for the individual experiments are shown in Table S2.