Extended Data Fig. 5: The ED pathway flux jumps upon nutrient upshifts.
From: A parallel glycolysis provides a selective advantage through rapid growth acceleration
a,b, Nutrient upshift experiments analogous to those conducted with [1,2-13C2]-glucose were replicated using [5,6-13C2]-glucose and the resulting labeling of (a) 6PG and (b) 3PG was measured via LC-MS. The labeling of M + 0 and M + 2 isotopomers revealed both the ED pathway flux and recursive PPP usage (Supplementary Note 3). c, Cell lysates from E. coli cultures grown on acetate were collected for an enzyme activity assay and incubated with 6PG, the direct precursor to KDPG (m/z = 257.0066) in the ED pathway. The increase in KDPG over time indicated the presence of the ED pathway enzymes in cells operating gluconeogenesis. Error bars represent the s.e.m. (n = 2 biological replicates). d, E. coli in the carbon-limited acetate medium underwent carbon upshift by [U-13C6]-glucose addition. The labeling of glycolytic intermediates following the upshift informed us of the fractions of 3PG pool coming from the labeled glucose and from the pre-upshift unlabeled acetate. This information was used to accurately compute glycolytic fluxes from [1,2-13C2]-glucose and [5,6-13C2]-glucose tracing. Error bars represent the s.e.m. (n = 3 biological replicates).
