Seminar Announcement – Arash Nikoubashman

Speaker: Prof. Dr. Arash Nikoubashman, Professor, Theory of Biologically Inspired Polymers, Leibniz Institute of Polymer Research Dresden

Title: “Molecular insights into biomolecular condensates from coarse-grained simulations”

Date: Tuesday, 02 June 2026

Time: 12:00

Room: Left Auditorium, CRTD, Fetscherstrasse 105, 01307 Dresden

Host: Research Training Group Biomolecular Condensates (RTG 3120)

Abstract: Biomolecular condensates are essential to cellular processes and organization, and are formed by weak, multivalent interactions among biomolecules, such as intrinsically disordered proteins (IDPs). Leveraging the conceptual parallels between IDPs and classical polymers, physics-based theories and molecular simulations provide powerful tools to unravel their structural and dynamic properties. Using this approach, we show that IDPs within condensates typically adopt swollen, coil-like configurations that gradually collapse as the chains transition from the dense core, through the interface, into the surrounding aqueous phase. Beyond the intrinsic organization of the IDPs themselves, we demonstrate that small-molecule cosolutes such as ATP can modulate the phase separation of IDPs and reshape the morphology of the condensed phase, e.g., from core-shell to dewetted architectures. This structural richness is mirrored by an equally rich dynamical behavior. Through a systematic analysis of model proteins built from negatively charged glutamic acid and positively charged lysine residues, we uncover a universal correlation between microscopic contact dynamics and mesoscopic material properties as the sequence charge pattern is varied: with increasing charge segregation, the diffusion coefficient of the chains within the dense phase decreases, while both the dense-phase viscosity and the condensate-water surface tension increase.