Strong links are important, but weak links stabilize them

Recently, a highly uneven distribution of metabolic network fluxes has been described in Escherichia coli that defines a high-flux backbone containing the most important (and most familiar) metabolic reactions. These findings might lead to a better understanding of the organization of the minimal gene set, and to a novel explanation for the allometric scaling laws. The scale-free distribution of the metabolic fluxes of E coli highlights the importance of weak links in metabolic, and other, networks. Several proven examples show that weak links might have a general role in the stabilization of a variety of complex systems and, in addition, provide novel interpretations of the role of water in the potential energy landscape of the protein-folding process.