Figure 7
ROS induction by TTFA also correlates with CII inhibition in isolated mitochondria at low succinate levels. (a and b) Mitochondria isolated from variant cells respiring on 500 μM succinate in an oxygraph chamber were exposed to increasing concentrations of TTFA, and ROS production was followed in real time in the presence of Amplex Ultra Red and peroxidase. (a) Shows increased ROS production for S68A variant compared with WT, (b) shows the higher ROS for R72C and no ROS for B9 cells. The same WT data are used in a and b, the panels are separated for clarity only. (c) Under the same conditions, 5 mM malonate inhibits ROS generation by 825 μM TTFA in all cell lines except for B9 cells. (d) Respiratory data extracted from the experiments shown in a reveal that the respiration of S68A cells is inhibited by TTFA most efficiently. Data represent mean±S.E.M. of 4–5 independent experiments. Significant differences from WT: *I56F, **S68A, #B9, ##R72C. c: * denotes a significant decrease after the addition of malonate
