SKM 2023 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 11: Poster Session I
BP 11.65: Poster
Dienstag, 28. März 2023, 12:30–15:30, P1
Electro-thermodynamics of coacervate interfaces — •Arghya Majee1, Christoph A. Weber2, and Frank Jülicher1,3,4 — 1Max Planck Institute for the Physics of Complex Systems, Dresden, Germany — 2Institute of Physics, University of Augsburg, Germany — 3Center for Systems Biology Dresden, Germany — 4Cluster of Excellence Physics of Life, TU Dresden, Germany
Biological condensates are assemblies of proteins and nucleic acid that provide biochemical compartments in the cell. Such condensates can form by coacervation since many condensate components are charged and condensate properties vary with salt concentration. While the thermodynamic description based on short ranged interactions is well established, a theory accounting for the role of electrostatic interactions in the presence of salt is lacking. Here, we propose an electro-thermodynamic theory of such systems taking into account the role of electrostatics. We find that two or even more charged layers can form at the interface, where charge neutrality is locally not obeyed. Depending on the values of parameters, such charge profiles and associated electrostatic potential profiles imply either reflection or attraction of single molecules diffusing across the interface. Such interface properties could also account for a varying tendency of droplets to fuse and be of relevance for chemical reactions inside biological condensates by selectively recruiting reacting components by charge.