Butyryl dehydrogenase reduction

Acyl CoA Dehydrogenases. Reaction (2) is catalyzed by a family of related enzymes. The lower fatty acid derivatives are oxidized by an enzyme purified from beef liver mitochondria. The isolated enzyme, butyryl dehydrogenase, has been reported to contain both riboflavin and copper.The nature of this enzyme will be discussed later in conjunction with other flavin enzjnmes. Chains of 3 to 8 carbons are oxidized in the presence of suitable electron acceptors, including 2,6-dichloro-phenolindophenol, cytochrome c, and ferricyanide. The maximum rate is obtained with butyryl CoA. It has been reported that the initial oxidation of fatty acid-CoA and the reduction of the employed electron acceptors are carried out by two different flavoproteins, which react with each... 

Li, F. et ed (2008) Coupled ferredoxin and crotonyl coenzyme A (CoA) reduction with NADH catalyzed by the butyryl-CoA dehydrogenase/Etf complex from Qostridium kluyveri. J. Bacterial., 190, 843-850. 

The sequence of reactions from 3 to 7, Fig. 5, was established in the following manner. Dehydrogenation of isobutyryl CoA was demonstrated with dialyzed liver extract, employing the oxidation-reduction indicator, triphenyltetrazolium chloride, as the hydrogen acceptor (87). Only the CoA derivate would serve as a substrate. Furthermore, Crane et al. (97) observed that the flavoprotein, butyryl CoA dehydrogenase, specific for straight chain acyl CoA derivatives from C4 to Cg, is reduced by isobut3rryl CoA. 

In the solvent-producing clostridia, butyryl-CoA dehydrogenase (enzyme 7 in Fig. 2.1) catalyzes the reduction of crotonyl-GoA... 

Additionally, the enzyme catalysing crotonyl-CoA reduction, butyryl-CoA dehydrogenase complex (Bcd-EtfAB), was replaced by tra/is-enoyl-CoA reductase (Ter) that catalyses an irreversible reduction. Furthermore, tra/w-enoyl-CoA reductase utilises NADH directly as the electron donor, thus is coupled to the driving force more tightly. 

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