2-Methylbutyryl CoA dehydrogenase from mitochondria of Ascaris suum and its relationship to NADH-dependent 2-methylcrotonyl CoA reduction.
Acyl CoA dehydrogenase and electron-transfer flavoprotein have been isolated and partially purified from mitochondria of the anaerobic nematode, Ascaris suum. Dehydrogenase activity was greatest with 2-methylbutyryl CoA and the relative substrate specificities of the ascarid dehydrogenase(s) differ greatly from their mammalian counterparts. It appears that the ascarid dehydrogenase functions physiologically as a reductase, catalyzing the final step in the synthesis of branched-chain fatty acids. In fact, incubations of A. suum mitochondrial membranes with electron-transfer flavoprotein, 2-methylbutyryl CoA dehydrogenase, 2-methylcrotonyl CoA and NADH resulted in a substantial, rotenone-sensitive, 2-methylbutyrate synthesis. These results suggest that the ascarid electron-transport chain and at least two soluble mitochondrial proteins are involved in the NADH-dependent reduction of 2-methylcrotonyl CoA.
D000214:Acyl Coenzyme A / Q000378:metabolism*; D000818:Animals; D001200:Ascaris / Q000201:enzymology*; D044927:Electron-Transferring Flavoproteins; D005182:Flavin-Adenine Dinucleotide / Q000494:pharmacology; D005420:Flavoproteins / Q000302:isolation & purification / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology*; D009243:NAD / Q000494:pharmacology*; D010088:Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D044925:Oxidoreductases Acting on CH-CH Group Donors; D012402:Rotenone / Q000494:pharmacology; D013379:Substrate Specificity
D000214:Acyl Coenzyme A; D044927:Electron-Transferring Flavoproteins; D005420:Flavoproteins; D012402:Rotenone; D009243:NAD; D005182:Flavin-Adenine Dinucleotide; C033618:tiglyl-coenzyme A; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C038808:2-methylacyl-CoA dehydrogenase