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Hindi Research Article, J Proteomics Enzymol Vol: 4 Issue: 2
The Expression Pattern of the Acetoacetyl-CoA Synthetase and its Kinetic Parameters Facilitate the Use of Ketone Bodies in Liver during Feeding
| Francesca Aguiló, Nuria Camarero, Ana Luísa De Sousa-Coelho, Mar Gacias, Pedro F Marrero* and Diego Haro | |
| Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Barcelona and the University of Barcelona Institute of Biomedicine(IBUB), Spain | |
| Corresponding author : Pedro F Marrero Biochemistry and Molecular, University of Barcelona, Diagonal 643, 08028 E-08028 Barcelona, Spain Tel: 34-93-403 45 00 E-mail: pedromarrero@ub.edu |
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| Received: November 13, 2015 Accepted: December 22, 2015 Published: December 29, 2015 | |
| Citation: Aguiló F, Camarero N, Sousa-Coelho ALD, Gacias M, Marrero F (2015) The Expression Pattern of the Acetoacetyl-CoA Synthetase and its Kinetic Parameters Facilitate the Use of Ketone Bodies in Liver during Feeding. J Proteomics Enzymol 4:2. doi:10.4172/2470-1289.1000124 |
Abstract
Acetoacetyl-CoA synthetase (AACS) is a cytoplasmic enzyme that activates the ketone body acetoacetate for lipogenesis. Aacs is expressed in liver, thus this tissue produces and consumes ketone bodies. To understand this apparent paradox we studied the expression of Aacs in liver during the transition from fasting to feeding, and characterized the kinetic parameters of the human enzyme. We show that Aacs liver expression is down-regulated by fasting and only up-regulated after 5 h of refeeding, while the levels of circulating ketone bodies returned to basal levels within 20 min of food availability. Since the human enzyme has a high affinity for the ketone body acetoacetate (KM = 37.6 μM), these results indicates that AACS utilizes ketones during periods of feeding. Human AACS was also characterized as an acetylated enzyme in vivo, where lysine 633 (from a P4XGK domain) plays a critical role in the catalytic activity but not in the acetylation state of the protein.