Driving force for pyruvate kinase in the mammalian cell line iBMK

Range -3.8 kJ/mol
Organism Mouse Mus musculus
Reference Park JO et al., Metabolite concentrations, fluxes and free energies imply efficient enzyme usage. Nat Chem Biol. 2016 May 2. doi: 10.1038/nchembio.2077. p.3 right column bottom paragraphPubMed ID27159581
Method Abstract: "Here [investigators] use isotope labeling to measure absolute metabolite concentrations and fluxes in Escherichia coli, yeast and a mammalian cell line. [They] then integrate this information to obtain a unified set of concentrations and ΔG for each organism."
Comments P.3 right column bottom paragraph: "Along with phosphofructokinase, pyruvate kinase is generally considered a committed step in glycolysis. Current textbooks indicate that almost the entire energy drop in glycolysis occurs at the phosphofructokinase and pyruvate kinase steps (Fig. 4b). Accordingly, [investigators] were surprised when [their] global analysis resulted in only a modest driving force for pyruvate kinase in the mammalian cell line iBMK (ΔG = −3.8 kJ/mol, implying a forward-to-backward flux ratio of 4.3)." iBMK=Immortalized Baby Mouse Kidney Epithelial Cells
Entered by Uri M
ID 112687