Intermediates in fatty acid oxidation.
1. Aqueous extracts of acetone-dried liver and kidney mitochondria, supplemented with NAD(+), CoA and phenazine methosulphate, efficiently convert fatty-acyl-CoA compounds into acetyl-CoA; the process was followed with an O(2) electrode. 2. Label from [1-(14)C]octanoyl-CoA appears in acetyl-CoA more rapidly than that from [8-(14)C]octanoyl-CoA. 3. Oxidation of [8-(14)C]octanoyl-CoA was terminated by addition of neutral ethanolic hydroxylamine and the resulting hydroxamates were separated chromatographically. Hydroxamate derivatives of 3-hydroxyoctanoyl-, hexanoyl-, butyryl- and acetyl-CoA were obtained. 4. These and other observations suggest that oxidation of octanoyl-CoA by extracts involves participation of free intermediates rather than uninterrupted complete degradation of individual molecules to acetyl-CoA by a multienzyme complex. 5. Intact liver mitochondria studied by the hydroxamate technique were also shown to form intermediates during oxidation of labelled octanoates. In addition to octanoylhydroxamate, [8-(14)C]octanoate gave rise to small amounts of hexanoyl-, butyryl- and 3-hydroxyoctanoyl-hydroxamate. In contrast with extracts, however, where the quantity of intermediates found was a significant fraction of the precursors, mitochondria oxidizing octanoate contained much larger quantities of octanoyl-CoA than of any other intermediate.
D000105:Acetyl Coenzyme A / Q000096:biosynthesis; D000818:Animals; D002210:Caprylates / Q000378:metabolism; D002247:Carbon Isotopes; D002417:Cattle; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D002854:Chromatography, Paper; D003065:Coenzyme A / Q000378:metabolism; D003201:Computers; D005227:Fatty Acids / Q000378:metabolism*; D005233:Fatty Alcohols / Q000096:biosynthesis; D006898:Hydroxylamines; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism*; D009928:Organ Specificity; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D010619:Phenazines / Q000378:metabolism; D051381:Rats; D013045:Species Specificity; D013329:Structure-Activity Relationship; D013464:Sulfuric Acids / Q000378:metabolism; D013997:Time Factors
D002210:Caprylates; D002247:Carbon Isotopes; D005227:Fatty Acids; D005233:Fatty Alcohols; D006898:Hydroxylamines; D010619:Phenazines; D013464:Sulfuric Acids; D000105:Acetyl Coenzyme A; D003065:Coenzyme A