Studies on the metabolism of glycolyl-CoA.
Glycolyl-CoA can be formed during the course of the beta-oxidation by rat liver mitochondria of 4-hydroxybutyrate. The existence of this beta-oxidation has been previously supported by the occurrence of 4-hydroxybutyrate and its beta-oxidation catabolites in urine from patients with 4-hydroxybutyric aciduria, an inborn error of gamma-aminobutyric acid metabolism due to the deficiency of succinic semialdehyde dehydrogenase. The characteristics of the mitochondrial beta-oxidation of 4-hydroxybutyrate were, in rat liver, compared with those of the mitochondrial beta-oxidation of butyrate. The inhibition by malonate of the oxidation of 4-hydroxybutyrate was about twofold weaker than that of oxidation of butyrate, whereas both oxidations were abolished by preincubating the mitochondria with 1 mM valproic acid, a known inhibitor of mitochondrial beta-oxidation. Mitochondria from rat kidney cortex were demonstrated to catalyse, as previously shown for hepatic mitochondria, the carnitine-dependent oxidation of 12-hydroxylauroyl-CoA-omega-Hydroxymonocarboxylyl-CoAs are thus concluded to be precursors of glycolyl-CoA also in rat kidney cortex. In addition, 3-hydroxypyruvate was found to be a precursor of glycolyl-CoA, since it was oxidized by bovine heart pyruvate dehydrogenase with a cofactor requirement similar to that of pyruvate oxidation. Glycolyl-CoA was a substrate of carnitine acetyltransferase (pigeon breast muscle). Pig heart citrate synthase was capable of catalyzing the condensation of glycolyl-CoA with oxaloacetate. The product of this reaction induced low NADH production rates dependent on the addition of porcine heart aconitase and isocitrate dehydrogenase.
Vamecq
J
J
Institut international de pathologie cellulaire et moléculaire et Université de Louvain, Bruxelles, Belgique.
Draye
J P
JP
Poupaert
J H
JH
D000106:Acetate-CoA Ligase / Q000378:metabolism; D000154:Aconitate Hydratase / Q000378:metabolism; D000214:Acyl Coenzyme A / Q000378:metabolism*; D000818:Animals; D002087:Butyrates / Q000378:metabolism; D020148:Butyric Acid; D002332:Carnitine O-Acetyltransferase / Q000378:metabolism; D002950:Citrate (si)-Synthase / Q000378:metabolism; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D007672:Kidney Cortex / Q000201:enzymology / Q000648:ultrastructure; D008297:Male; D008928:Mitochondria / Q000201:enzymology; D008930:Mitochondria, Liver / Q000201:enzymology*; D010084:Oxidation-Reduction; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012978:Sodium Oxybate / Q000378:metabolism
D000214:Acyl Coenzyme A; D002087:Butyrates; D011768:Pyruvate Dehydrogenase Complex; D011773:Pyruvates; D020148:Butyric Acid; C065813:glycoyl-coenzyme A; D012978:Sodium Oxybate; C012375:hydroxypyruvic acid; D007521:Isocitrate Dehydrogenase; D002332:Carnitine O-Acetyltransferase; D002950:Citrate (si)-Synthase; D000154:Aconitate Hydratase; D000106:Acetate-CoA Ligase