Figure 3

Complex I activity in various cells. (A) Complex I activity in healthy fibroblasts as a function of amount (in micrograms protein added) of mitochondria added. (B) Complex I activity in mitochondria isolated from patient cells mutated in C6ORF66; data for F528, F334 and F511 cells, as compared with activity in mitochondria isolated from healthy fibroblasts, are shown. The effect on complex I activity is shown for TAT-ORF added to isolated mitochondria from F528 cells (C). TAT-ORF was added to patients’ cells: F528 (D), F334 (E), F511 (F) and nonrelevant NDUFS2 cells (G); mitochondria was isolated and complex I activity was measured. TAT-ORF was added at a final concentration of 0.022 µg/µL (C–F) or 0.032 µg/µL (G), for 3 h (C) or 24 h (D–G). Complex I activity was measured as described in Material and Methods. Activity values are expressed as nmol/min/mg protein and presented as average of triplicates ± standard deviation (SD).