System-Level Insights into Yeast Metabolism by Thermodynamic Analysis of Elementary Flux Modes
Figure 1
Overview of procedure to identify thermodynamically feasible EFMs.
We use a metabolic network model of S. cerevisiae together with physiological data (e.g., growth rate, glucose uptake, ethanol production) in flux variability analysis (FVA) to determine reaction reversibilities and reaction activities for the specific conditions. Subsequently, we apply NET analysis to determine additional reaction direction constraints based on the activities of reactions that are active for all flux distributions. With the resulting condition specific reaction directionalities, we calculate all the EFMs for the metabolic network. Finally, we use quantitative metabolite data to test the reaction activities of each EFM for thermodynamic feasibility.