Formation of acetoacetate from 3-hydroxy-3-methylglutarate by rat liver and isolation of a mitochondrial coenzyme A-transferase activity involved.
1. Formation of acetoacetate from 3-hydroxy-3-methylglutarate was observed in the perfused rat liver. Production of 3.5mumol of acetoacetate/h per g of tissue was obtained. 2. Formation of acetoacetate was catalysed mainly by the mitochondrial fraction of the homogenized liver, at a rate of 62nmol/h per mg of protein. 3. Experiments with hydroxy-[3-(14)C]methylglutarate demonstrated that the acetoacetate formed was derived mainly from this compound. 4. A mitochondrial transferase activity catalysing the transfer of a CoA molecule from succinyl-CoA (3-carboxypropionyl-CoA) to hydroxymethylglutarate was shown. The K(m) value for hydroxymethylglutarate was 5x10(-3)m.
D000090:Acetoacetates / Q000096:biosynthesis*; D000818:Animals; D002250:Carbon Radioisotopes; D002498:Centrifugation; D003065:Coenzyme A / Q000378:metabolism*; D005612:Freeze Drying; D005977:Glutarates / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology*; D010477:Perfusion; D051381:Rats; D013347:Subcellular Fractions; D013386:Succinates / Q000378:metabolism; D013466:Sulfurtransferases / Q000302:isolation & purification* / Q000378:metabolism
D000090:Acetoacetates; D002250:Carbon Radioisotopes; D005977:Glutarates; D013386:Succinates; D013466:Sulfurtransferases; D003065:Coenzyme A