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      https://www.ias.ac.in/article/fulltext/jbsc/010/02/0171-0179

    • Keywords

       

      Lipoic acid; acetyl coenzyme A; acetyl dihydrolipoic acid; citrate synthase

    • Abstract

       

      Rat liver lipoyl transacetylase catalyzes the formation of acetyl dihydrolipoic acid from acetyl coenzyme A and dihydrolipoic acid. In an earlier paper the formation of acetyl dihydrolipoic from pyruvate and dihydrolipoic acid catalyzed by pyruvate dehydrogenase has been reported. Acetyl dihydrolipoic acid is a substrate for citrate synthase, acetyl coenzyme A carboxylase and fatty acid synthetase. The Vmax. for citrate synthase with acetyl dihydrolipoic acid was identical to acetyl coenzyme A (approximately 1 μmol citrate formed/min/mg protein) while the apparent Km was approximately 4 times higher with acetyl dihydrolipoic acid as the substrate. This may be due to the fact that synthetic acetyl dihydrolipoic acid is a mixture of 4 possible isomers and only one of them may be the substrate for the enzymatic reaction. While dihydrolipoic acid can replace coenzyme A in the activation of succinate catalyzed by succinyl coenzyme A synthetase, the transfer of coenzyme A between succinate and acetoacetyl dihydrolipoic acid catalyzed by succinyl coenzyme A: 3 oxo-acid coenzyme A transferase does not occur.

    • Author Affiliations

       

      S S Wagh1 V M Gandhi1 C V Natraj1 K K G Menon1

      1. Hindustan Lever Research Centre, Andheri (East), Bombay - 400099, India
    • Dates

       
  • Journal of Biosciences | News

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