Fig. 4: Functional analysis for the determination of the H⁺/ATP ratio.

a Time courses of the ATP synthesis/hydrolysis activity of the reconstituted proteoliposomes (PLs) at different pmf. ATP synthesis reaction was measured using the luciferin/luciferase system. The reaction quotient, Q was 2.5; [ATP] = 500 nM, [ADP] = 20 µM, [Pi] = 10 mM. The rate of catalysis was determined from the initial slopes (bold lines). b The ATP synthesis/hydrolysis rates determined from (a) were plotted against pmf. The data points were fitted with an exponential function for the determination of the equilibrium pmf, pmf_eq, as the interception of the x axis. c Determination of the H⁺/ATP ratio. The mean (filled circles) and the SD of \(F\cdot {{pmf}}_{{eq}}\) values were determined from 3 to 4 independent biological replicates (open circles) at each Q condition using different batches of purified enzymes, and \(2.3{RT}\cdot \log Q\) values were plotted against the corresponding \(F\cdot {{pmf}}_{{eq}}\) values according to Eq. (5). Sample sizes (n) from left to right are: 3, 3, 3, 4, 3 (WT) and 4, 3, 3, 4, 3 (δ_ΔN-α). Each line represents a linear regression fit to the dataset obtained from each F_oF₁.