Formation of acetoacetate from 3-hydroxy-3-methylglutarate by rat liver and isolation of a mitochondrial coenzyme A-transferase activity involved |
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| Authors: | R. Deana R. Meneghello L. Manzi C. Gregolin |
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| Affiliation: | Department of Medical Biochemistry, University of Nairobi, Nairobi, Kenya, and Institute of Biological Chemistry, University of Padova, `Centro per lo Studio della Fisiologia dei Mitocondri del C.N.R.'', 35100 Padova, Italy |
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| Abstract: | 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. |
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