Figure 6.

Electron-Transfer from SMOB-Pyridine Nucleotide Complexes to Cytochrome c. Reactions shown were initiated by rapid mixing in the stopped-flow. Curves passing through the data represent the best exponential fits through the absorbance data recorded at 550 nm. Reactions of 25 μM reduced SMOB-NADH complex prepared by anaerobic titration of 70 μM NADH with 30 μM oxidized cytochrome c (blue) and 18 μM oxidized SMOB with 400 μM NADH and 30 μM cytochrome c (red) were fit with monoexponential (k = 30 s⁻¹) and biexponential (k₁, k₂ ~50 s⁻¹). Inset shows the best monoexponential fit through data from the reaction of 5 μM oxidized cytochrome c with 25 μM reduced SMOB-NAD⁺ complex prepared by anaerobic titration with stoichiometric dithionite and 3 mM NAD⁺ (k = 13.6 s⁻¹).