|Bacteria Escherichia coli
|Henry CS, Broadbelt LJ, Hatzimanikatis V. Thermodynamics-based metabolic flux analysis. Biophys J. 2007 Mar 1 92(5):1792-805 Table - link PubMed ID17172310
|Andersen KB, von Meyenburg K. Charges of nicotinamide adenine nucleotides and adenylate energy charge as regulatory parameters of the metabolism in Escherichia coli. J Biol Chem. 1977 Jun 25 252(12):4151-6. Table - link PubMed ID16925
|A new form of metabolic flux analysis (MFA) called thermodynamics-based metabolic flux analysis (TMFA) is introduced with the capability of generating thermodynamically feasible flux and metabolite activity profiles on a genome scale. Researchers utilized TVA (Thermodynamic variability analysis) to determine if the physiological levels of the concentration ratios ATP/ADP, NAD/NADH, and NADP/NADPH maintained inside the cell are due to thermodynamic constraints by exploring the range of thermodynamically feasible values for these ratios. Researchers also used TVA to study the limits on the ratio of the intracellular pH to the extracellular pH as all transport of ions across the cell membrane depends on this ratio. The minimum and maximum ratios found are shown in Table link along with the values for these ratios found in the literature. Primary source-Methods for measurements of catabolic reduction charge (defined as NADH/(NADH+NAD+)) and anabolic reduction charge (defined as NADPH/(NADPH + NADP+)) are described using [14C]nicotinamide labeling of Escherichia coli cultures. Together with these parameters the adenylate energy charge (ATP + 1/2ADP)/(ATP + ADP + AMP) was measured using labeling with [2-3H]adenine. These three charges were found under different exponential growth conditions to have values independent of the growth conditions: catabolic reduction charge, 0.05 anabolic reduction charge, 0.45 and adenylate energy charge, 0.9.
|Ratio is from Table II in Primary ref, link where a mean anabolic charge of 0.45±0.04 for E. coli grown on a variety of carbon sources is given.