Electron paramagnetic resonance and magnetic circular dichroism studies of electron‐transfer flavoprotein‐ubiquinone oxidoreductase from pig liver
- 21 December 1987
- journal article
- Published by Wiley in FEBS Letters
- Vol. 226 (1) , 129-133
- https://doi.org/10.1016/0014-5793(87)80565-3
Abstract
Pig liver electron‐transfer flavoprotein‐ubiquinone oxidoreductase has been investigated by room temperature UV‐visible, low‐temperature electron paramagnetic resonance and low‐temperature magnetic circular dichroism spectroscopies. The results provide unambiguous evidence for the presence of a single [4Fe‐4S] cluster that is diamagnetic in the isolated enzyme and becomes paramagnetic with an S = , ground state on reduction with dithionite or enzymatically with the physiological electron donor. The EPR data for samples at pH 7.8 indicate that FAD is reduced by one electron to the anionic semiquinone form in the enzymatically reduced enzyme, and by two electrons to the hydroquinone form by excess dithionite. The possibility of weak spin‐spin interaction between the FAD semiquinone and the [4Fe‐4S]1+ center is discussed in the light of the observation of a small increase in the linewidth of the Fe‐S EPR in enzymatically reduced samples.Keywords
This publication has 15 references indexed in Scilit:
- Electron transfer flavoprotein-ubiquinone oxidoreductase from pig liver: purification and molecular, redox, and catalytic propertiesBiochemistry, 1985
- Resonance Raman studies of ETF dehydrogenase (an iron sulfur flavoprotein)Biochemical and Biophysical Research Communications, 1983
- Electron transfer flavoprotein from pig liver mitochondria. A simple purification and re-evaluation of some of the molecular propertiesBiochemical Journal, 1983
- Low-temperature magnetic circular dichroism evidence for the conversion of four-iron-sulphur clusters in a ferredoxin from Clostridium pasteurianum into three-iron-sulphur clustersBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1981
- Electron spin relaxation of the electron paramagnetic resonance spectra of cytochrome cBiochimica et Biophysica Acta (BBA) - Protein Structure, 1980
- Participation of the iron-sulphur cluster and of the covalently bound coenzyme of trimethylamine dehydrogenase in catalysisBiochemical Journal, 1978
- A new membrane iron-sulfur flavoprotein of the mitochondrial electron transfer system the entrance point of the fatty acyl dehydrogenation pathway?Biochemical and Biophysical Research Communications, 1975
- [38] Preparation and propertiesof clostridial ferredoxinsPublished by Elsevier ,1972
- On the Existence of Spectrally Distinct Classes of Flavoprotein Semiquinones. A New Method for the Quantitative Production of Flavoprotein Semiquinones*Biochemistry, 1966
- An electron transport factor from ClostridiumpasteurianumBiochemical and Biophysical Research Communications, 1962