Mathematical model for the application of Metabolic Flux Analysis to CHO cells producing recombinant human erythropoietin
Abstract
Mathematical modeling of metabolism meets several important applications in the context of bioprocess engineering, such as the interpretation of cell physiology. Metabolic Flux Analysis, one of the tools of this discipline, was used in the present work to characterize the biosynthesis of recombinant human erythropoietin in CHO cells. In order to apply this method, we built a matrix of stoichiometric numbers representing the major metabolic pathways for the generation of energy and the synthesis of essential precursors for product and biomass accumulation. Equations representing the biosynthesis of recombinant human erythropoietin and the growth of CHO were also derived, conferring an advantage to the proposed model over other existing designs. The dimensions of the obtained matrix were 47 × 44, with a rank of 44 and a condition number of 83; therefore, the model has a unique solution and is not sensitive. The metabolic flux map obtained by solving the mathematical model using experimental data showed results consistent with the known biochemistry of CHO cells and with the findings of other reports on this and other mammalian cell lines. The general steps of the methodology used to obtain the proposed mathematical model are also outlined.
