Speaker: Arash Nikoubashman (Leibniz Institute of Polymer Research & TU Dresden)
Title: Plastic life: What polymer physics can teach us about living cells

Abstract:

The cytoplasm of living cells typically contains high concentrations of macromolecular components, such as semiflexible filaments that enhance mechanical stability and (partially) folded proteins that can spontaneously form biomolecular condensates. These condensates are crucial for signal transduction, stress response, and regulated reactions. The functions of these macromolecular building blocks are closely linked to their conformations, and misfolded proteins are increasingly implicated in neurodegenerative diseases like amyotrophic lateral sclerosis (ALS). Given the conceptual similarities between biological macromolecules and classical polymers, physics-based theories and computer simulations are valuable tools for understanding, predicting, and engineering the properties of both natural and synthetic proteins. In this talk, I will present key insights from our coarse-grained molecular simulations and discuss the complexities and limitations of these models. Our findings reveal that unfolded proteins exhibit weak, heterogeneous interactions distributed along the chain contour. Additionally, proteins at the condensate-water interface are collapsed and tangentially oriented. We have also discovered that the phase behavior and material properties of biomolecular condensates can be accurately predicted from the conformations of single protein chains in solution. These insights advance our understanding of cellular processes at a biomolecular level and have potential implications for developing “digital twins” of living cells and new therapeutic strategies.

Data and Place: July 12, 12:10-
Room 107, 16th building. Komaba Campus, The University of Tokyo
zoom: https://u-tokyo-ac-jp.zoom.us/j/82391386658?pwd=xCc16tS9qBDCfTtR4PfdNEkcpOvU5k.1