FIGURE 1.

Reduced minus oxidized IR difference spectrum of rTAO. Reduction oxidation transformations were induced electrochemically in 100 mm potassium phosphate, 100 mm KCl at pH (black trace)/pD (red trace) 7.0 and containing 500 μm potassium ferricyanide and 100 μm benzyl viologen as redox mediators. Working electrode potentials were −400 mV for reduction and +550 mV for oxidation. For further details, see “Experimental Procedures.” Published ubiquinol-10 minus ubiquinone-10 redox spectra recorded in both H₂O (black) and D₂O (red) media are also displayed for qualitative comparisons (37).