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Steady-state modelling of metabolic flux between the tricarboxylic acid cycle and the glyoxylate bypass in Escherichia coli.
Comput Appl Biosci. 1994 Jun; 10(3):295-9.CA

Abstract

In this study, mathematical modelling, using the computer package MetaModel, was employed to calculate the steady-state fluxes and the concentration of various metabolites of the central pathways during growth of Escherichia coli on acetate. This package also enabled us to formulate the matrices of the elasticity coefficients and the control and response coefficients under different steady states. In this paper, we have assessed the relative contribution of the competing enzymes at the metabolic junction of isocitrate, i.e. isocitrate dehydrogenase (ICDH) and isocitrate lyase (ICL), to the overall distribution of carbon flux among the enzymes of the central pathways thus extending the pioneering work of Walsh and Koshland on the partition of carbon flux between the two metabolic cycles of the tricarboxylic acid and the glyoxylate bypass. This study revealed that ICDH is not 'rate limiting' during growth on acetate and that flux through ICL is essential not only to replenish the central pathways with biosynthetic precursors but also to sustain a high intracellular level of isocitrate. Furthermore, above certain threshold concentration of ICL, the Krebs cycle and the glyoxylate bypass work in concert and the partition of carbon flux between ICDH and ICL is no longer a problem.

Authors+Show Affiliations

Department of Biological Sciences, Napier University of Edinburgh, Scotland, UK.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

7922686

Citation

el-Mansi, E M., et al. "Steady-state Modelling of Metabolic Flux Between the Tricarboxylic Acid Cycle and the Glyoxylate Bypass in Escherichia Coli." Computer Applications in the Biosciences : CABIOS, vol. 10, no. 3, 1994, pp. 295-9.
el-Mansi EM, Dawson GC, Bryce CF. Steady-state modelling of metabolic flux between the tricarboxylic acid cycle and the glyoxylate bypass in Escherichia coli. Comput Appl Biosci. 1994;10(3):295-9.
el-Mansi, E. M., Dawson, G. C., & Bryce, C. F. (1994). Steady-state modelling of metabolic flux between the tricarboxylic acid cycle and the glyoxylate bypass in Escherichia coli. Computer Applications in the Biosciences : CABIOS, 10(3), 295-9.
el-Mansi EM, Dawson GC, Bryce CF. Steady-state Modelling of Metabolic Flux Between the Tricarboxylic Acid Cycle and the Glyoxylate Bypass in Escherichia Coli. Comput Appl Biosci. 1994;10(3):295-9. PubMed PMID: 7922686.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Steady-state modelling of metabolic flux between the tricarboxylic acid cycle and the glyoxylate bypass in Escherichia coli. AU - el-Mansi,E M, AU - Dawson,G C, AU - Bryce,C F, PY - 1994/6/1/pubmed PY - 1994/6/1/medline PY - 1994/6/1/entrez SP - 295 EP - 9 JF - Computer applications in the biosciences : CABIOS JO - Comput Appl Biosci VL - 10 IS - 3 N2 - In this study, mathematical modelling, using the computer package MetaModel, was employed to calculate the steady-state fluxes and the concentration of various metabolites of the central pathways during growth of Escherichia coli on acetate. This package also enabled us to formulate the matrices of the elasticity coefficients and the control and response coefficients under different steady states. In this paper, we have assessed the relative contribution of the competing enzymes at the metabolic junction of isocitrate, i.e. isocitrate dehydrogenase (ICDH) and isocitrate lyase (ICL), to the overall distribution of carbon flux among the enzymes of the central pathways thus extending the pioneering work of Walsh and Koshland on the partition of carbon flux between the two metabolic cycles of the tricarboxylic acid and the glyoxylate bypass. This study revealed that ICDH is not 'rate limiting' during growth on acetate and that flux through ICL is essential not only to replenish the central pathways with biosynthetic precursors but also to sustain a high intracellular level of isocitrate. Furthermore, above certain threshold concentration of ICL, the Krebs cycle and the glyoxylate bypass work in concert and the partition of carbon flux between ICDH and ICL is no longer a problem. SN - 0266-7061 UR - https://www.unboundmedicine.com/medline/citation/7922686/Steady_state_modelling_of_metabolic_flux_between_the_tricarboxylic_acid_cycle_and_the_glyoxylate_bypass_in_Escherichia_coli_ DB - PRIME DP - Unbound Medicine ER -