Properties of the general acyl-CoA dehydrogenase from pig liver

The properties of the general acyl coenzyme A dehydrogenase from pig liver and the stable reduced dehydrogenase . product and oxidized dehydrogenase . acetoacetyl-CoA complexes of the dehydrogenase were investigated. The enzyme has a molecular weight of 178,000 to 183,000 determined by gel filtration chromatography and by gel electrophoresis at different acrylamide concentrations. The subunit molecular weight is 45,000 based on acrylamide gel electrophoresis in the presence of dodecyl sulfate which agrees with the minimum molecular weight calculated from the flavin:protein ratio and the amino acid analysis. The subunits are identical, or very similar, as judged by quantitative NH2-terminal analysis and mapping of tryptic peptides. Immunochemical analyses by the complement fixation technique show that the structure of the oxidized enzyme is different from the structure of enzyme . acyl-CoA complexes whether the flavin in these complexes is in the oxidized or reduced state. The amino acid analysis, isoelectric point, and a procedure for crystallizing the dehydrogenase are also reported.