Consistency analysis of metabolic correlation networks
1 Bioinformatics Group, Department of Biology, Darmstadt University of Technology, 64287 Darmstadt, Germany
2 Max-Planck-Institute of Molecular Plant Physiology, Science Park Golm, 14424 Potsdam, Germany
3 School of Engineering and Science, Jacobs University Bremen, 28759 Bremen, Germany
BMC Systems Biology 2007, 1:44 doi:10.1186/1752-0509-1-44Published: 24 September 2007
Metabolic correlation networks are derived from the covariance of metabolites in replicates of metabolomics experiments. They constitute an interesting intermediate between topology (i.e. the system's architecture defined by the set of reactions between metabolites) and dynamics (i.e. the metabolic concentrations observed as fluctuations around steady-state values in the metabolic network).
Here we analyze, how such a correlation network changes over time, and compare the relative positions of metabolites in the correlation networks with those in established metabolic networks derived from genome databases. We find that network similarity indeed decreases with an increasing time difference between these networks during a day/night course and, counter intuitively, that proximity of metabolites in the correlation network is no indicator of proximity of the metabolites in the metabolic network.
The organizing principles of correlation networks are distinct from those of metabolic reaction maps. Time courses of correlation networks may in the future prove an important data source for understanding these organizing principles.