Figure 4: (a) Quenching of the fluorescence of 1,8-ANS probe associated with mitochondria by oxymyoglobin. 1–8 – MbO2 concentrations are 0, 3.8, 7.5, 11.1, 14.5, 17.8, 21.0 and 24.1 μM, respectively (incubation medium without succinate: Tris-HCl buffer, 10 mM; sucrose, 250 mM; EGTA, 0.5 mM; KH2PO4, 5 mM, pH 7.4.). Excitation wavelength is 360 nm, emission spectrum maximum is 470 nm, monochromator slit widths (for excitation and emission) are 5×5 nm. (b) Plot of the 1,8-ANS corrected fluorescence intensity in the spectral maximum (Fcorr) vs. MbO2 concentration (pH 7.4). Inset: determination of the constant of MbO2 binding to mitochondria in the quenching complex.