Glycerol supports growth of the Trypanosoma brucei bloodstream forms in the absence of glucose: Analysis of metabolic adaptations on glycerol-rich conditions
Fig 5
Incorporation of [U-13C]-glycerol into BSF intracellular metabolites.
The 427 90–13 BSF parental cell line was incubated for 1 h in PBS containing 2 mM [U-13C]-glycerol alone or in the presence of 2 mM glucose (Panel A). The figure shows the 13C-enrichment of key metabolites of the intermediate metabolism at 0 to 6 carbon positions (m0 to m6, colour code indicated, "mx" denotes metabolites in which x of the atoms are 13C instead of 12C) with 13C expressed as percentage of all corresponding molecules (MID; Mass Isotopomer Distribution). Error bars indicate means ± SD of 3 biological replicates. The metabolic scheme in panel B represents the enzymatic reactions leading to production of the analysed metabolites from glycerol metabolism (bold faced and underlined ones). Gluconeogenesis and mannose 5-phosphate production are shown in red and part of the pentose phosphate pathway is in blue. The carbon sources incorporated in the metabolism network ([U-13C]-glycerol and CO2) are circled and the excreted end products are boxed. For abbreviations see Fig 1, other abbreviations are: Ala, alanine; M6P, mannose 6-phosphate; 2/3PG, 2- or 3-phosphoglycerate (these two metabolites are undistinguished by IC-MS/MS); 6PG, 6-phosphogluconate; 6PGL, 6-phosphogluconolactone; P5P, pentose 5P including ribose 5-phosphate (Ribo5P), ribulose 5-phosphate (Ribu5P) and xylulose 5-phosphate (Xylu5P), which are undistinguished by IC-MS/MS.