Structure of electron transfer flavoprotein-ubiquinone oxidoreductase and electron transfer to the mitochondrial ubiquinone pool

Cross-linking of the electron-transfer flavoprotein to electron-transfer flavoprotein-ubiquinone oxidoreductase with heterobifunctional reagents.

The mitochondrial electron-transfer flavoprotein (ETF) is a heterodimer containing only one FAD. In previous work on the structure-function relationships of ETF, its interaction with the general acyl-CoA dehydrogenase (GAD) was studied by chemical cross-linking with heterobifunctional reagents [D. J. Steenkamp (1987) Biochem. J. 243, 519-524]. GAD whose lysine residues were substituted with 3-(...

Alternative quinone substrates and inhibitors of human electron-transfer flavoprotein-ubiquinone oxidoreductase.

Electron-transfer flavoprotein (ETF)-ubiquinone (2,3-dimethoxy-5-methyl-1,4-benzoquinone) oxidoreductase (ETF-QO) is a membrane-bound iron-sulphur flavoprotein that participates in an electron-transport pathway between eleven mitochondrial flavoprotein dehydrogenases and the ubiquinone pool. ETF is the intermediate electron carrier between the dehydrogenases and ETF-QO. The steady-state kinetic...

The indispensability of phospholipid and ubiquinone in mitochondrial electron transfer from succinate to cytochrome c.

The indispensability of phospholipid and ubiquinone (Q) in mitochondrial electron transfer was studied by depleting phospholipid and Q in succinate-cytochrome c reductase and then replenishing the depleted enzyme. More than 90% of phospholipid and Q was removed by repeated ammonium sulfate-cholate fractionation. The depleted succinate-cytochrome c reductase showed no enzymatic activity for succ...

Electron and Proton Transfer in NADH: Ubiquinone Oxidoreductase (Complex I) from Escherichia coli

Deficiency of electron transfer flavoprotein or electron transfer flavoprotein:ubiquinone oxidoreductase in glutaric acidemia type II fibroblasts.

Glutaric acidemia type II (GA II) is a human genetic disorder. It has been suggested that the primary defect in this disorder is a deficiency of a protein involved in electron transport between the acyl-CoA dehydrogenases and the bc1 complex of the mitochondrial respiratory chain. Antisera were raised to purified porcine electron transfer flavoprotein (ETF) and electron transfer flavoprotein:ub...