M+1 | M+2 | M+3 | |
---|---|---|---|
Medium | |||
Lactate | 0.3 ± 0.15 | 2.7 ± 0.3 | 61.1 ± 3.4a |
Cell extract | |||
Glutamate | 8.8 ± 1.0 | 5.1 ± 1.6 | 6.5 ± 0.5 |
Aspartate | 16 ± 4 | 1.1 ± 0.5 | NE |
Malate | NE | 2.5 ± 0.8 | 1.3 ± 0.8 |
Citrate | NE | NE | 2.4 ± 1.1 |
Medium and cell extracts were analyzed for GC/MS, except for glutamate, which was analyzed by liquid chromatography/MS because of peak overlap in the GC/MS for this metabolite. M+x is the molecular weight of the metabolite plus x number of 13C atoms incorporated. NE, Not enriched. n = 5 for lactate, malate, citrate, and aspartate; n = 3 for glutamate; mean ± SEM.
↵aDirectly from glycolysis.