Electron-balance during the oxidative self-inactivation of cytochrome c

During the oxidative self-inactivation of cytochrome c, four molecular events were detected and kinetically characterized; heme destruction, loss of the iron–sulfur coordination, protein multimerization, and protein inactivation. Electron transfer balance from the four molecular events account for 100% of the electrons transferred in the first minute of protein incubation with hydrogen peroxide. However, an unidentified electron source started donating electrons after the first minute and reaches 23% of the transferred electrons after 10 min incubation. Thus, the electron transfer kinetics and its balance allowed us to detect a non-considered electron transfer and free radical formation.