Metabolic Dissipative Structures - Systems Biology of Metabolic and Signaling Networks - page 174

Chapter 8
Metabolic Dissipative Structures
Ildefonso Mtz. de la Fuente
Abstract The self-organization of metabolic processes, such as the spontaneous
dissipative formation of macromolecular structures, the functional coordination
between multienzymatic complexes, and the emergence of molecular rhythms, is
one of the most relevant topics in the post-genomic era. Herein, I analyze some
aspects of self-organization in metabolic processes utilizing information theory to
quantifying biomolecular information flows in bits, an approach that enables the
visualization of emergent effective connectivity structures. Specifically, I deter-
mined the emergent functional integrative processes arising from irreversible
enzymatic steps in yeast glycolysis, and in the systemic metabolic structure.
Experimental observations and numerical studies with dissipative metabolic
networks have shown that enzymatic activity can spontaneously self-organize
leading to the emergence of a systemic metabolic structure, characterized by a set
of different enzymatic reactions always locked into active states, i.e., the metabolic
core, while the remaining catalytic processes are intermittently active. This global
metabolic structure was verified in Escherichia coli , Helicobacter pylori , and
Saccharomyces cerevisiae , and it seems to be a common key feature for all cells.
The observed effective connectivity in both the irreversible enzymatic steps of
yeast glycolysis and the systemic metabolic structure is highly dynamic and
characterized by significant variations of biomolecular causality flows. These
effective connectivity flows reflect the integration of catalytic processes within
multienzymatic systems, and their functional coordination. The resulting functional
integrative structures appear to be fundamental motifs in the dissipative self-
organization and self-regulation of cellular metabolism.
I.M. de la Fuente ( * )
BioCruces Health Research Institute, Barakaldo, Basque Country, Spain
Institute of Parasitology and Biomedicine “L´pez Neyra”, CSIC, Granada, Spain
Department of Mathematics, University of the Basque Country, EHU-UPV., Leioa, Spain