Standard Gibbs energy of metabolic reactions: V. enolase reaction

Publication date: Available online 18 January 2020Source: Biochimica et Biophysica Acta (BBA) - Proteins and ProteomicsAuthor(s): Thorsten Greinert, Kristina Vogel, Astrid-Ina Seifert, Riko Siewert, Irina V. Andreeva, Sergey P. Verevkin, Thomas Maskow, Gabriele Sadowski, Christoph HeldAbstractThe glycolytic pathway is one of the most important pathways for living organisms, due to its role in energy production and as supplier of precursors for biosynthesis in living cells. This work focuses on determination of the standard Gibbs energy of reaction ΔRg′0 of the enolase reaction, the ninth reaction in the glycolysis pathway. Exact ΔRg′0 values are required to predict the thermodynamic feasibility of single metabolic reactions or even of metabolic reaction sequences under cytosolic conditions. So-called “apparent” standard data from literature are only valid at specific conditions. Nevertheless, such data are often used in pathway analyses, which might lead to misinterpretation of the results. In this work, equilibrium measurements were combined with activity coefficients in order to obtain new standard values ΔRg′0 for the enolase reaction that are independent of the cytosolic conditions. Reaction equilibria were measured at different initial substrate concentrations and temperatures of 298.15, 305.15 and 310.15 K at pH 7. The activity coefficients were predicted using the equation of state electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-S...
Source: Biochimica et Biophysica Acta (BBA) Proteins and Proteomics - Category: Biochemistry Source Type: research