Semiquinone Q10 EPR signal with unusual relaxation parameters
Ruuge, E.K.; Konstantinov, A.A.
Biofizika 21(3): 586-588
1976
ISSN/ISBN: 0006-3029 PMID: 183837 Document Number: 106731
A narrow symmetrical peak with g = 2.00 is observed in the ESR spectrum of submitochondrial particles in the absence of added substrates. An unusual feature of this free-radical signal is that it cannot be saturated with microwave power up to 200 mw at -30.degree. C. The signal is not significantly affected by cyanide, antimycin or malonate but is greatly abolished by ferricyanide and succinate dehydrogenase inhibitor .alpha.-tenoyltrifluoracetone. The signal may arise from the semiquinone Q10 complex with the oxidized high-potential iron-sulfur center of the succinate dehydrogenase.