Open AccessHigh-resolution 13C nuclear magnetic resonance studies of glucose metabolism in Escherichia coli.
Author(s) -
Kâmil Uğurbil,
Toronto Brown,
Jan A. den Hollander,
Paul Glynn,
R. G. Shulman
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.8.3742
Subject(s) - valine , escherichia coli , biochemistry , alanine , citric acid cycle , fructose , glycolysis , catabolism , carbon 13 nmr , tricarboxylic acid , aldolase a , metabolism , chemistry , biology , nuclear magnetic resonance , amino acid , stereochemistry , enzyme , physics , gene
High-resolution 13C nuclear magnetic resonance spectra of suspensions of Escherichia coli cells have been obtained at 90.5 MHz by using the Fourier transform mode. Anaerobic cells incubated with [I-13C]glucose show a time course of glycolysis in which the alpha and beta glucose anomers disappear at different rates, lactate, succinate, acetate, alanine, and valine accumulate as end products of glycolysis, and fructose bisphosphate appears as an intermediate. It is shown that fructose bisphosphate is labeled at C-1 and C-6 during [I-13C]-glucose catabolism. Upon oxygenation, glutamate appears with the 13C ENRICHMENT AT THE C-4, C-3, and C-2 positions, with the C-4 most intense. From the position of the 13C label we conclude that valine is formed by condensation of pyruvate and that carbon enters the tricarboxylic acid cycle mainly through acetyl CoA.