Figure 4

Oxidation of membrane-bound cytochrome c by CoM-S-S-CoB. The reduction of cytochrome c was performed as described in the caption to Figure 3. The 100-μl reaction mixture consisted of membranes (400 μg protein), 2 μM ferredoxin, 1 μg FNR and 1 mM NADPH. FNR was added at time zero and 0.32 mM (final concentration) CoM-S-S-CoB was added (arrow). Reduction and oxidation of cytochrome c was monitored by the absorbance at 554 nm.