Thermodynamic equilibrium of highly exergonic metabolic reactions

Adenosintriphosphate (ATP) is a central metabolic molecule in any known organism. The cleavage of highly energetic anhydride bonds of ATP enables reactions that would not occur spontaneously under cellular conditions. The ATP hydrolysis thereby fuels many important reactions in cellular metabolism.
The hybrid approach used in this work allowed the determination of Standard Gibbs free energy of the individual reactions and from that the determination of Standard Gibbs free energy of ATP hydrolysis as a single reaction.
The results from this work were compared to previous works that did not consider the activity coefficients of the reactants. It could the demonstrated, that our approach leads to thermodynamically consistent results for the highly exergonic individual reactions as well as for the ATP hydrolysis reaction approached through formation of a reaction system of individual reactions. Furthermore the comparability of results based upon measurements at different experimental conditions could be ensured by accounting for the activity coefficients of reactants through thermodynamic modelling with ePC-SAFT.