Background: Biochemically detailed stoichiometric matrices have now been reconstructed for various bacteria, yeast, and for the human cardiac mitochondrion based on genomic and proteomic data. These networks have been manually curated based on legacy data and elementally and charge balanced. Comparative analysis of these well curated networks is now possible. Pairs of metabolites often appear together in several network reactions, linking them topologically. This co-occurrence of pairs of metabolites in metabolic reactions is termed herein "metabolite coupling." These metabolite pairs can be directly computed from the stoichiometric matrix, S. Metabolite coupling is derived from the matrix T, whose off-diagonal elements indicate the number of reactions in which any two metabolites participate together, where is the binary form of S. Results: Metabolite coupling in the studied networks was found to be dominated by a relatively small group of highly interacting pairs of metab...
Scott A. Becker, Nathan D. Price, Bernhard O. Pals