Figure 10.

Molar relations in the electron transfer from MDH₂ to O₂ (A), XTT (B), or Cyt c (C) at pH 7.5. A, Various amounts of MDH₂ dissolved in ethanol were added to HEPES in the absence or presence of XTT (100 μm). The amounts of O₂ consumed were measured when the reaction was completed (after 6–10 min). B and C, Reduction of XTT (100 μm; B) or Cyt c (100 μm; C) in the absence or presence of SOD (100 μg mL⁻¹) measured after completion of the reaction (after 1–2 min).