Metabolites 2012, 2(3), 632-647; doi:10.3390/metabo2030632

A Topological Characterization of Medium-Dependent Essential Metabolic Reactions

1,2,* email, 3email and 2email
Received: 1 August 2012; in revised form: 28 August 2012 / Accepted: 12 September 2012 / Published: 24 September 2012
(This article belongs to the Special Issue Metabolic Network Models)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Metabolism has frequently been analyzed from a network perspective. A major question is how network properties correlate with biological features like growth rates, flux patterns and enzyme essentiality. Using methods from graph theory as well as established topological categories of metabolic systems, we analyze the essentiality of metabolic reactions depending on the growth medium and identify the topological footprint of these reactions. We find that the typical topological context of a medium-dependent essential reaction is systematically different from that of a globally essential reaction. In particular, we observe systematic differences in the distribution of medium-dependent essential reactions across three-node subgraphs (the network motif signature of medium-dependent essential reactions) compared to globally essential or globally redundant reactions. In this way, we provide evidence that the analysis of metabolic systems on the few-node subgraph scale is meaningful for explaining dynamic patterns. This topological characterization of medium-dependent essentiality provides a better understanding of the interplay between reaction deletions and environmental conditions.
Keywords: flux-balance analysis; metabolic networks; network motifs
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MDPI and ACS Style

Sonnenschein, N.; Marr, C.; Hütt, M.-T. A Topological Characterization of Medium-Dependent Essential Metabolic Reactions. Metabolites 2012, 2, 632-647.

AMA Style

Sonnenschein N, Marr C, Hütt M-T. A Topological Characterization of Medium-Dependent Essential Metabolic Reactions. Metabolites. 2012; 2(3):632-647.

Chicago/Turabian Style

Sonnenschein, Nikolaus; Marr, Carsten; Hütt, Marc-Thorsten. 2012. "A Topological Characterization of Medium-Dependent Essential Metabolic Reactions." Metabolites 2, no. 3: 632-647.

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