The survival and proliferation of cells URLanisms 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 a number of factors such as cytosolic space, energy expenditure , or nitrogen availability . While extensive work has been done to study constrained optimization problems based  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 a solution of the non-linear optimization problem is necessarily an elementary flux mode . This finding has significant consequences for our understanding of metabolic switches as well as for the  computation of optimal fluxes in kinetic metabolic networks.
The survival and proliferation of cells URLanisms 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.
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a number of factors
finite resources that are shared between all enzymes,
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, or nitrogen availability
for amino-acid synthesis, or micro-nutrients
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only
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a solution
optimal solutions
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is necessarily an elementary flux mode
are elementary flux modes
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metabolic switches
optimality in metabolic networks
A
identification of metabolic switches and the
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fluxes
flux distributions