Concentrations of the intracellular metabolites involved in the lumped GAPDH and PGK reactions and their subsequent ratios for approximately the same biomass-specific glucose consumption rates under aerobic and anaerobic conditions

Range Table - link
Organism Budding yeast Saccharomyces cerevisiae
Reference Bekers KM, Heijnen JJ1, van Gulik WM. Determination of the in vivo NAD/NADH ratio in S. cerevisiae under anaerobic conditions using alcohol dehydrogenase as sensor reaction. Yeast. 2015 Jun 9. doi: 10.1002/yea.3078. p.554 table 1PubMed ID26059529
Method Abstract: "In this work [investigators] quantified free NAD:NADH ratios in yeast under anaerobic conditions, using alcohol dehydrogenase (ADH) and the lumped reaction of glyceraldehyde-3-phosphate dehydrogenase and 3-phosphoglycerate kinase as sensor reactions."
Comments P.554 right column bottom paragraph: "The lower free NAD:NADH ratio (more reduced redox status) under anaerobic conditions has some major implications for the intracellular levels of the metabolites involved in glycolysis. For reactions that operate close to equilibrium, as is the case for GAPDH, the mass action ratio is close to the Keq at all times. As a consequence, a decreasing free NAD:NADH ratio would result in a shift of the mass action ratio from the thermodynamic equilibrium, and will thus be compensated by the ratios of the other products and reactants involved in the reaction. Table 1 shows the intracellular concentrations of these metabolites under aerobic and anaerobic conditions for the same glycolytic flux (for a complete overview, see supporting information, Figures S3, S4 and S5). Measurements of the cytosolic Pi concentrations are not available, but from the results of Gonzalez et al. (2000) it can be expected that this concentration is about a factor of 1.5 higher for anaerobic compared to aerobic conditions." GAPDH=glyceraldehyde-3-phosphate dehydrogenase. PGK=3-phosphoglycerate kinase
Entered by Uri M
ID 112807