Dresden 2011 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 10: Posters I
DY 10.42: Poster
Monday, March 14, 2011, 17:00–19:00, P4
Diffusive Coupling Can Discriminate Between Similar Reaction Mechanisms in an Allosteric Enzyme System — •Ronny Straube1 and Ernesto M. Nicola2 — 1Systems Biology Group, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany — 2Institute for Cross-Disciplinary Physics and Complex Systems, Campus UIB, Palma de Mallorca, Spain
Recently, inward rotating spiral waves (anti-spirals) have been observed in cell free yeast extracts [1]. Such anti-spirals were, so far, only observed in purely chemical systems. To elucidate the molecular mechanism leading to this unusual wave dynamics we compare two mechanisms of product activation for the allosteric enzyme phosphofructokinase. We find that a sequential activation mechanism as in the Monod-Wyman-Changeux (WMC) model is able to generate inward propagating waves while a simple Hill function as employed in the Selkov model is not [2]. The occurrence of inward propagating waves is related to the sensitivity of the enzyme cooperativity with respect to the activator concentration, and we show that the waves generated by the MWC mechanism are more stable against long wave length perturbations. These results explicitly show how the type and the stability of macroscopically observable wave patterns depend on the underlying molecular reaction mechanism in a simple allosteric enzyme system.
[1] R. Straube, S. Vermeer, E. M. Nicola, T. Mair, Biophys. J. 99, L4-L6 (2010). [2] R. Straube, E. M. Nicola, BMC Systems Biology 4:165 (2010).