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Identification of metabolic fluxes in hepatic cells from transient 13 C‐labeling experiments: Part II. Flux estimation
Author(s) -
Maier Klaus,
Hofmann Ute,
Reuss Matthias,
Mauch Klaus
Publication year - 2007
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.21746
Subject(s) - metabolic flux analysis , metabolite , glycolysis , flux (metallurgy) , biochemistry , pentose phosphate pathway , isotopic labeling , citric acid cycle , chemistry , intracellular , metabolism , steady state (chemistry) , metabolic pathway , cytosol , in silico , chromatography , enzyme , organic chemistry , gene
This contribution addresses the identification of metabolic fluxes and metabolite concentrations in mammalian cells from transient 13 C‐labeling experiments. Whilst part I describes experimental set‐up and acquisition of required metabolite and 13 C‐labeling data, part II focuses on setting up network models and the estimation of intracellular fluxes. Metabolic fluxes were determined in glycolysis, pentose‐phosphate pathway (PPP), and citric acid cycle (TCA) in a hepatoma cell line grown in aerobic batch cultures. In glycolytic and PPP metabolite pools isotopic stationarity was observed within 30 min, whereas in the TCA cycle the labeling redistribution did not reach isotopic steady state even within 180 min. In silico labeling dynamics were in accordance with in vivo 13 C‐labeling data. Split ratio between glycolysis and PPP was 57%:43%; intracellular glucose concentration was estimated at 101.6 nmol per 10 6 cells. In contrast to isotopic stationary 13 C‐flux analysis, transient 13 C‐flux analysis can also be applied to industrially relevant mammalian cell fed‐batch and batch cultures. Biotechnol. Bioeng. 2008;100: 355–370. © 2007 Wiley Periodicals, Inc.