title: Isovaleryl-CoA dehydrogenase: demonstration in rat liver mitochondria by ion exchange chromatography and isoelectric focusing.
abstract: There has been ambiguity concerning the specificity of the enzymes that dehydrogenate short branched-chain acyl-CoAs. It previously had been assumed that isovaleryl-CoA is dehydrogenated by n-butyryl-CoA dehydrogenase [butyryl-CoA:(acceptor) oxidoreductase, EC 1.3.99.2]. To solve this problem, we fractionated five short-chain acyl-CoA dehydrogenases (isovaleryl-CoA, n-butyryl-CoA, isobutyryl-CoA, n-octanoyl-CoA, and glutaryl-CoA dehydrogenases) from rat liver mitochondria by isoelectric focusing and DEAE-cellulose column chromatography. The isovaleryl-CoA dehydrogenase [isovaleryl-CoA:(acceptor) oxidoreductase, EC 1.3.99.10] peak was almost completely separated from the peaks of n-butyryl CoA- and n-octanoyl-CoA dehydrogenases by isoelectric focusing, and it was well separated from glutaryl-CoA dehydrogenase [glutaryl-CoA:(acceptor) oxidoreductase (decarboxylating), EC 1.3.99.7] and n-octanoyl-CoA dehydrogenase by DEAE-cellulose column chromatography. The isovaleryl-CoA dehydrogenase peak partly overlapped that of n-butyryl-CoA and isobutyryl-CoA dehydrogenases in the latter procedure. These results unequivocally demonstrate that isovaleryl-CoA is oxidized by a specific isovaleryl-CoA dehydrogenase. The other dehydrogenase peaks also demonstrated activity toward a single substrate, except that isobutyryl-CoA dehydrogenase activity could not be clearly resolved from n-butyryl-CoA dehydrogenase activity.
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange; D044943:Fatty Acid Desaturases / Q000302:isolation & purification / Q000378:metabolism*; D007525:Isoelectric Focusing; D050769:Isovaleryl-CoA Dehydrogenase; D008930:Mitochondria, Liver / Q000201:enzymology*; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; D051381:Rats; D014631:Valerates
chemical_list: D014631:Valerates; D010088:Oxidoreductases; D044943:Fatty Acid Desaturases; D044925:Oxidoreductases Acting on CH-CH Group Donors; D050769:Isovaleryl-CoA Dehydrogenase