Enzyme allocation problems in kinetic metabolic networks: Optimal solutions are elementary flux modes

JOURNAL OF THEORETICAL BIOLOGY

卷:347

Article

Mueller, Stefan^1,2  Regensburger, Georg¹  Steuer, Ralf³ 

[1] Austrian Acad Sci, Johann Radon Inst Computat & Appl Math, A-4040 Linz, Austria

[2] Acad Sci Czech Republ, CzechGlobe Global Change Res Ctr, Brno 60300, Czech Republic

[3] Humboldt Univ, Inst Theoret Biol, D-10115 Berlin, Germany

关键词: Metabolic optimization;    Enzyme kinetics;    Oriented matroid;    Elementary vector;    Conformal sum;   

DOI  :  10.1016/j.jtbi.2013.11.015

来源: Elsevier

【 摘 要 】

The survival and proliferation of cells and organisms require a highly coordinated allocation of cellular resources to ensure the efficient synthesis of cellular components. In particular, the total enzymatic capacity for cellular metabolism is limited by finite resources that are shared between all enzymes, such as cytosolic space, energy expenditure for amino-acid synthesis, or micro-nutrients. While extensive work has been done to study constrained optimization problems based only on stoichiometric information, mathematical results that characterize the optimal flux in kinetic metabolic networks are still scarce. Here, we study constrained enzyme allocation problems with general kinetics, using the theory of oriented matroids. We give a rigorous proof for the fact that optimal solutions of the non-linear optimization problem are elementary flux modes. This finding has significant consequences for our understanding of optimality in metabolic networks as well as for the identification of metabolic switches and the computation of optimal flux distributions in kinetic metabolic networks. (C) 2013 Elsevier Ltd. All rights reserved.

【 授权许可】

Free