Partial purification and characterization of glutaryl-coenzyme A dehydrogenase, electron transfer flavoprotein, and electron transfer flavoprotein-Q oxidoreductase from Paracoccus denitrificans.

摘要: Glutaryl-coenzyme A (CoA) dehydrogenase and the electron transfer flavoprotein (ETF) of Paracoccus denitrificans were purified to homogeneity from cells grown with glutaric acid as carbon source. Glutaryl-CoA had a molecular weight 180,000 was made up four identical subunits weights about 43,000 each which contained one flavin adenine dinucleotide molecule. The enzyme catalyzed an oxidative decarboxylation glutaryl-CoA crotonyl-CoA, maximally stable at pH 5.0, lost activity readily values above 7.0. optimum in range 8.0 8.5, catalytic center 960 min-1, apparent Michaelis constants for pig liver ETF 1.2 2.5 microM, respectively. P. visible spectrum that two subunits, only isoelectric point 4.45 compared 6.8 ETF. accepted electrons not dehydrogenase, but also butyryl-CoA octanoyl-CoA dehydrogenases. Vmax similar magnitude either or acceptor these used assay reduction ubiquinone 1 by ETF-Q oxidoreductase cholate extracts membranes. could accept bacterial In case, Km infinitely high. contaminating paramagnets, resultant preparation paramagnetic resonance signals 2.081, 1.938, 1.879 G, those mitochondrial enzyme.