Title
Theoretical aspects of 13C metabolic flux analysis with sole quantification of carbon dioxide labeling
Abstract
The potential of using sole respirometric CO"2 labeling measurement for ^1^3C metabolic flux analysis was investigated by metabolic simulations. For this purpose a model was created, considering all CO"2 forming and consuming reactions in the central catabolic and anabolic pathways. To facilitate the interpretation of the simulation results, the underlying metabolic network was parameterized by physiologically meaningful flux parameters such as flux partitioning ratios at metabolic branch points and reaction reversibilities. For real case flux scenarios of the industrial amino acid producer Corynebacterium glutamicum and different commercially available ^1^3C-labeled tracer substrates, observability and output sensitivity towards key flux parameters was investigated. Metabolic net fluxes in the central metabolism, involving, e.g. glycolysis, pentose phosphate pathway, tricarboxylic acid cycle, anaplerotic carboxylation, and glyoxylate pathway were found to be determinable by the respirometric approach using a combination of [1-^1^3C] and [6-^1^3C] glucose in two parallel studies. The reversibilities of bidirectional reactions influence the isotopic labeling of CO"2 only to a negligible degree. On one hand, they therefore cannot be determined. On the other hand, their precise values are not required for the quantification of net fluxes. Computer-aided optimal experimental design was carried out to predict the quality of the information from the respirometric tracer experiments and identify suitable tracer substrates. A combination of [1-^1^3C] and [6-^1^3C] glucose in two parallel studies was found to yield a similar quality of information as compared to an approach with mass spectrometric labeling analysis of secreted products. The quality of information can be further increased by additional studies with [1,2-^1^3C"2] or [1,6-^1^3C"2] glucose. Respirometric tracer studies with sole labeling analysis of CO"2 are therefore promising for ^1^3C metabolic flux analysis. for ^1^3C metabolic flux analysis.
Year
DOI
Venue
2005
10.1016/j.compbiolchem.2005.02.005
Computational Biology and Chemistry
Keywords
Field
DocType
AMM,IDV,IMMs,MDV,MS,PPP,TCA
Corynebacterium glutamicum,Biological system,Metabolic flux analysis,Metabolic network,Isotopic labeling,Chemistry,Glyoxylate cycle,Pentose phosphate pathway,Flux,Chromatography,Genetics,Anabolism
Journal
Volume
Issue
ISSN
29
2
Computational Biology and Chemistry
Citations 
PageRank 
References 
3
0.90
0
Authors
3
Name
Order
Citations
PageRank
Tae Hoon Yang191.37
Elmar Heinzle2122.08
Christoph Wittmann3202.12