Novel fatty acid beta-oxidation enzymes in rat liver mitochondria. I. Purification and properties of very-long-chain acyl-coenzyme A dehydrogenase.
Freeze-thawed rat liver mitochondria were extensively washed with potassium phosphate, pH 7.5, and the residue was extracted with 10 mM potassium phosphate, pH 7.5, 1% (w/v) sodium cholate, 0.5 M KCl. The four beta-oxidation enzyme activities of the washes and the last extract were assayed with substrates of various carbon chain lengths. Our data suggest that the last extract contains a novel acyl-CoA dehydrogenase and long-chain 3-hydroxyacyl-CoA dehydrogenase. A novel acyl-CoA dehydrogenase was purified. The molecular masses of the native enzyme and the subunit were estimated to be 150 and 71 kDa, respectively. One mole of enzyme contained 2 mole of FAD. These properties and immunochemical properties of the enzyme differed from those of three other acyl-CoA dehydrogenases: short-, medium-, and long-chain acyl-CoA dehydrogenases. Carbon chain length specificity of the enzyme differed from that of other acyl-CoA dehydrogenases. The enzyme was active toward CoA esters of long- and very-long-chain fatty acids, but not toward those of medium- and short-chain fatty acids. The specific enzyme activity was greater than 10 times that of long-chain acyl-CoA dehydrogenase when palmitoyl-CoA was used as substrate. We propose the name "very-long-chain acyl-CoA dehydrogenase" for this enzyme.
Izai
K
K
Department of Pediatrics, Gifu University School of Medicine, Japan.
Uchida
Y
Y
Orii
T
T
Yamamoto
S
S
Hashimoto
T
T
D044942:Acyl-CoA Dehydrogenase, Long-Chain / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002853:Chromatography, Liquid; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology*; D008970:Molecular Weight; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains
D003902:Detergents; D005182:Flavin-Adenine Dinucleotide; D044942:Acyl-CoA Dehydrogenase, Long-Chain