High-resolution 13C nuclear magnetic resonance spectra of suspensions of E. coli cells have been obtained at 90.5 MHz by using the Fourier transform mode. Anaerobic cells incubated with [1-13C]glucose show a time course of glycolysis in which the α and β 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 [1-13C]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 it is concluded that valine is formed by condensation of pyruvate and that carbon enters the tricarboxylic acid cycle mainly through acetyl CoA.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1978|