Thermodynamic feasibility analyses help evaluating the feasibility of metabolic pathways. This is an important information used to develop new biotechnological processes and to understand metabolic processes in cells. However, literature standard data are uncertain for most biochemical reactions yielding wrong statements concerning their feasibility. In this article we present activity-based equilibrium constants for all the ten glycolytic reactions, accompanied by the standard reaction data (standard Gibbs energy of reaction and standard enthalpy of reaction). We further developed a thermodynamic activity-based approach that allows to correctly determine the feasibility of glycolysis under different chosen conditions.
Fig: Comparison between the concentration-based standard Gibbs energy of reaction (striped bars)and the activity-based standard Gibbs energy of reaction (white bars) of the glycolytic TPI reaction (5), GAPDH reaction (6), PGK reaction (7), PGAM reaction (8) and enolase reaction (9) at 298.15 K and pH 7.0 based on. Please note that H+ was not considered for GAPDH reaction in the original source, but was added by us as this is a reaction participant.
The results show for the first time that the feasibility of glycolysis can be explained by thermodynamics only if (1) correct standard data are used and if (2) the conditions in the cell at non-equilibrium states are accounted for in the analyses. The results here will help to determine the feasibility of other metabolisms and to understand metabolic processes in cells in the future.
Greinert, T., Vogel, K., Maskow, T. et al. New thermodynamic activity-based approach allows predicting the feasibility of glycolysis. Sci Rep11, 6125 (2021). https://doi.org/10.1038/s41598-021-85594-8