Monoepoxide production from linoleic acid by cytochrome c in the presence of cardiolipin.

We found that cytochrome c (Cyt c) could oxidize cardiolipin (CL), and detected monoepoxides of linoleic acid (LA) in the fatty acids constituting the oxidized CL. We also found that in the presence of CL and Cyt c, free LA was oxidized and LA monoepoxides were produced. The aim of this study was to elucidate the mechanism of this lipid peroxidation. We concluded that ferric Cyt c produced some radical species from water-soluble oxygen in the presence of CL (CL-Cyt c system) and that radicals oxidized free LA or CL. The CL-Cyt c system may be another LA monoepoxide producing system in the neutrophil and may account for the lipid peroxidation observed in the ischemia-reperfusion-induced cardiac injury.