Fig. 3.

Isolated mitochondrial Cx-II activity vs. pH. Isolated complex-II (Cx-II) activity assays from freeze-thawed mitochondria demonstrated a pH-dependent relationship over the range pH 6.6–7.8. (A): Isolated Cx-II activity from heart mitochondria. (B): Isolated Cx-II activity from liver mitochondria. One-way ANOVA with Tukey's test for multiple comparisons was performed. Data are means +SEM. In A, N = 6 biological replicates; four technical replicates per N. In B, N = 5 biological replicates; four technical replicates per N. Statistical differences were determined between all pH values, but values denoted in the figure are in comparison to pH 7.4. For each applied pH (i.e. pHmito), the equivalent pHcyto is shown underneath, assuming ΔpH = 0.4 units.