FIGURE 5.

H₂O₂ production during RET in the presence of various respiratory chain inhibitors and in the presence and absence of Δp and ΔpH. H₂O₂ production rates were measured using the HRP-Amplex Red detection system during the linear phases of the reactions and normalized to the value from the standard RET condition (20 mm succinate, 1 mm ATP+MgSO₄, KCN). Δp was collapsed with gramicidin, and ΔpH increased using 20 mm KCl or decreased using 20 mm KCl and 2 nm nigericin (see “Results”). See “Experimental Procedures” for conditions.