A Method to Constrain Genome-Scale Models with 13C Labeling Data
Fig 9
Flux comparison with COBRA predictions for pyk KO at 5 hours.
The comparison of flux predictions through COBRA methods with fluxes measured through 2S-13C MFA shows how and why predictive methods fail. Left panel: Predicted fluxes for reactions in the pentose phosphate pathway (PPP) through FBA using maximum growth, FBA using maximum ATP production and 13C MOMA are compared with measurements through 2S-13C MFA (shading indicates confidence intervals). Fluxes predicted through maximum growth FBA offer a good qualitative description of fluxes but are quantitatively erroneous. 13C MOMA is a variation of MOMA that leverages 2S-13C MFA flux profiles and predicts fluxes more accurately. Center and right panels: Flux maps for two special cases (FBA and 2S-13C MFA). Maximum growth FBA overestimates flux into the PPP. Flux values are depicted in red: the upper value is the flux for the best fit and the lower values are the range of values compatible with data from 13C labeling experiments.