Soft Matter and Complex Systems Seminar

Significant fraction of cell’s volume is occupied by various proteins, polysaccharides, RNAs etc. Such crowding substantially reduces the mobility of macromolecules, and affects both thermodynamics and kinetics of intracellular processes. While prior research has mainly focused on the dependence of translational mobility on occupied volume fraction, studies of the effect of crowder shape are still scarce. In this work, we fill this gap by investigating self-diffusion in mixtures of spherical and elongated macromolecules with Fluorescence Correlation Spectroscopy (FCS) and Brownian Dynamics (BD) simulations. Our results emphasize that diffusion in crowded systems is determined not merely by the occupied volume fraction, but that the shape of crowders matters, which is relevant to diverse intracellular environments.