In vivo enzymatic activity of acetylCoA synthetase in skeletal muscle revealed by 13C turnover from hyperpolarized [1-13C]acetate to [1-13C]acetylcarnitine

Détails

ID Serval
serval:BIB_45B4D7F11A1B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
In vivo enzymatic activity of acetylCoA synthetase in skeletal muscle revealed by 13C turnover from hyperpolarized [1-13C]acetate to [1-13C]acetylcarnitine
Périodique
Biochimica et Biophysica Acta (BBA) - General Subjects
Auteur(s)
Bastiaansen Jessica A.M., Cheng Tian, Mishkovsky Mor, Duarte João M.N., Comment Arnaud, Gruetter Rolf
ISSN
0304-4165
ISSN-L
1872-8006
Statut éditorial
Publié
Date de publication
08/2013
Peer-reviewed
Oui
Volume
1830
Numéro
8
Pages
4171-4178
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't Publication Status: ppublish
Résumé
BACKGROUND: Acetate metabolism in skeletal muscle is regulated by acetylCoA synthetase (ACS). The main function of ACS is to provide cells with acetylCoA, a key molecule for numerous metabolic pathways including fatty acid and cholesterol synthesis and the Krebs cycle.
METHODS: Hyperpolarized [1-(13)C]acetate prepared via dissolution dynamic nuclear polarization was injected intravenously at different concentrations into rats. The (13)C magnetic resonance signals of [1-(13)C]acetate and [1-(13)C]acetylcarnitine were recorded in vivo for 1min. The kinetic rate constants related to the transformation of acetate into acetylcarnitine were deduced from the 3s time resolution measurements using two approaches, either mathematical modeling or relative metabolite ratios.
RESULTS: Although separated by two biochemical transformations, a kinetic analysis of the (13)C label flow from [1-(13)C]acetate to [1-(13)C]acetylcarnitine led to a unique determination of the activity of ACS. The in vivo Michaelis constants for ACS were KM=0.35±0.13mM and Vmax=0.199±0.031μmol/g/min.
CONCLUSIONS: The conversion rates from hyperpolarized acetate into acetylcarnitine were quantified in vivo and, although separated by two enzymatic reactions, these rates uniquely defined the activity of ACS. The conversion rates associated with ACS were obtained using two analytical approaches, both methods yielding similar results.
GENERAL SIGNIFICANCE: This study demonstrates the feasibility of directly measuring ACS activity in vivo and, since the activity of ACS can be affected by various pathological states such as cancer or diabetes, the proposed method could be used to non-invasively probe metabolic signatures of ACS in diseased tissue.
Mots-clé
Acetate-CoA Ligase/metabolism, Acetates/metabolism, Acetylcarnitine/metabolism, Animals, Carbon Isotopes, Male, Muscle, Skeletal/enzymology, Rats, Rats, Sprague-Dawley
Pubmed
Web of science
Création de la notice
29/04/2013 12:52
Dernière modification de la notice
03/03/2018 16:46
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