Fig. 5.

Effects of NaCN (A), oligomycin (B) and various counter anions of magnesium salts (C) on proton-pumping activities of DKO membrane reconstituted with WT complex I. (A) Proton-pumping activity of WT-DKO membrane was measured in the presence of 20 μM DQ, 150 μM NADH and various NaCN concentrations. Trace 1 represents the control with no NaCN. Traces 2 through 7 represent NaCN concentrations at 2, 4, 6, 8, 10 and 15 mM, respectively. (B) Proton-pumping activity of WT-DKO membrane was measured in the presence of 20 μM DQ, 150 μM NADH and various oligomycin at 0, 5, 10 and 15 μg/ml. Traces 1–4 correspond increasing oligomycin concentrations. The plots of amplitudes of acidification (ΔF) versus NaCN or oligomycin concentrations are shown in the insets in Fig. 4A and B, respectively. (C) Proton-pumping activity (IAR, initial acidification rate) of WT-DKO membrane was measured in 20 mM of the various magnesium salts. Averages and standard deviations were calculated from four trials. The asterisk symbols on the top of the bars indicate that the difference with respect to the control is statistically significant (P < 0.05).