Beta-oxidation of unsaturated fatty acids in humans. Isoforms of delta 3, delta 2-enoyl-CoA isomerase.
This investigation was undertaken in order to elucidate the human enzymes which participate in metabolism of the double bonds of unsaturated fatty acids during beta-oxidation. The results indicate that the human monofunctional delta 3, delta 2-enoyl-CoA isomerase (EC 5.3.3.8) with the native M(r) of 70,000 differed significantly from its rat counterpart [Palosaari et al. (1990) J. Biol. Chem. 265, 3347-3353]; the isoelectric point of the human isoform was over three pH-units more acidic, it showed different chromatographic behaviour, the human enzyme did not show any clear-cut substrate chain-length specificity and only a weak immunological cross-reactivity was detected with the antibody to rat liver mitochondrial short-chain enzyme. This explains the failure of attempts to apply the rat data directly to human beings. Another isomerase activity from human liver was found to be a part of the isomerase-hydratase-dehydrogenase polypeptide showing immunological cross-reactivity with the previously characterized peroxisomal multifunctional enzyme (MFE) from rat liver.
Kilponen
J M
JM
Department of Medical Biochemistry, University of Oulu, Finland.
Hiltunen
J K
JK
D000818:Animals; D019748:Carbon-Carbon Double Bond Isomerases; D064006:Dodecenoyl-CoA Isomerase; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D007535:Isomerases / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D010084:Oxidation-Reduction; D051381:Rats; D013379:Substrate Specificity
D005231:Fatty Acids, Unsaturated; D007527:Isoenzymes; D007535:Isomerases; D019748:Carbon-Carbon Double Bond Isomerases; D064006:Dodecenoyl-CoA Isomerase; C576298:ECI1 protein, human; C119738:ECI2 protein, human