Figure 11. Proposed electron transfer pathways for PEG-HCCs.

PEG-HCCs are reduced by NAD(P)H and Asc and can donate electrons to superoxide, CytC, or potentially the oxygen reduction site Cyt_a3 on Complex IV. Transferring electrons to CytC from NADH would bypass inhibited Complexes I and III. Transferring electrons from NAD(P)H to Cyt_a3 would bypass impairment of Complexes I, III, and IV while providing electrons to reduce dioxygen to water. Red dashed arrows: example of electron leakage sites. Green dashed arrow: potential bypassing effects of cyanide. Green solid arrows: potential electron transfer pathways.