Berlin 2005 – scientific programme

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SYBN: Biological and Social Networks

SYBN 2: Biologische und Soziale Netzwerke II

SYBN 2.4: Talk

Monday, March 7, 2005, 13:00–13:20, TU HE101

Structural and game-theoretical analysis of biochemical networks — •Stefan Schuster — Universität Jena, Lehrstuhl für Bioinformatik, Ernst-Abbe-Platz 2, 07743 Jena

A major challenge in biology is to clarify the relationship between structure and function in complex intracellular networks. Dynamic mathematical modelling of large-scale metabolic and regulatory networks meets difficulties as the necessary mechanistic detail is rarely available. In contrast, structure-oriented methods such as metabolic pathway analysis only require network topology. One of the central concepts in this analysis is that of elementary flux modes. Here, we explain that concept and an algorithm for calculating all elementary modes. We show that it is well-suited for determining routes enabling maximum yields of bioconversions and for analysing redundancy and robustness properties of living cells. For understanding the characteristics of metabolic pathways, evolutionary game theory is a promising approach. Two species of micro-organisms that use the same nutrient, but may choose between two different pathways of ATP production, can be considered as players in the sense of game theory. The pathways are regarded as distinct strategies to which payoffs can be assigned. The payoffs are assumed to be proportional to the steady-state number of individuals sustainable on the basis of these strategies. For each species (or strain), this number does not only depend on the strategy chosen by that species but also on the strategy of the other species. In a certain parameter range, the payoffs fulfil the conditions for the prisoner’s dilemma.