Fig. 4: Evaluation of paramagnetic cofactors from healthy and FRDA LCLs’ mitochondria by EPR spectroscopy.

A Western blotting analysis for the subcellular fractionation of LCLs. Cells were fractionated to nuclear, cytosolic and mitochondrial fractions by sequential centrifugation. Equal volumes of the samples (i.e., 5 μL) were loaded in each lane. Vinculin, lamin B1 and ATP5A have been chosen as cytosolic, nuclear and mitochondrial markers, respectively. The reported western blot refers to the subcellular fractionation of the healthy LCLs used in this work. B EPR spectra acquired at 15 K of the mitochondrial enriched fractions from LCLs. The superimposed spectra are reported with a different color for each cell line: dark gray, control; red, FRDA1; light blue, FRDA2. The inset on the spectra at 15 K refers to the signal of N2 cluster from complex I magnified by factor of 8. C EPR spectra acquired at 100 K, colors as in B.