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DY: Fachverband Dynamik und Statistische Physik
DY 10: Nonlinear Dynamics, Synchronization and Chaos
DY 10.1: Vortrag
Montag, 18. März 2024, 15:00–15:15, BH-N 128
Biochemical pH oscillators in giant lipid vesicles — •Arthur Straube1,2, Guillermo Olicón-Méndez2, Maximilian Engel3,2, Felix Höfling2,1, and Stefanie Winkelmann1 — 1Zuse Institute Berlin — 2Fachbereich Mathematik und Informatik, Freie Universität Berlin — 3Korteweg-de Vries Institute, University of Amsterdam
We study pH oscillators confined to giant lipid vesicles serving as an open reactor [1]. In contrast to conventional pH oscillators in closed reactors, the exchange with the vesicle exterior periodically resets the pH clock that switches the system from acid to basic, resulting in self-sustained oscillations. We analyze the structure of the limit cycle, which controls the dynamics for giant vesicles and dominates the strongly stochastic oscillations in small vesicles of submicrometer size [2]. Based on an accurate reduced two-variable model [1], we further apply geometric singular perturbation theory [3] to rigorously analyze the structure underlying the limit cycle. Insights into the mechanism of pH oscillations for a single oscillator is crucial for rationalizing experiments and understanding communication of vesicles and synchronization of rhythms.
[1] A.V. Straube, S. Winkelmann, F. Höfling, J. Phys. Chem. B. 127, 2955 (2023). [2] A.V. Straube, S. Winkelmann, C. Schütte, F. Höfling, J. Phys. Chem. Lett. 12, 9888 (2021). [3] M. Engel, G. Olicón-Méndez, accepted by Contemp. Math. (preprint arXiv:2305.18021).
Keywords: enzyme-reaction networks; biochemical rhythms; relaxation oscillators; fast-slow dynamical systems; singular perturbation theory