Exchange Dynamics of Single Molecule in Phase Separated Droplet

Within cells, condensates formed by liquid-liquid phase separation (LLPS) play a crucial role in regulating various biological processes. Unlike membrane-bound organelles, LLPS condensates are distinguished by their rapid exchange of substances with the surrounding environment. This dynamic property enables condensates to form functional biomolecular complexes swiftly, and facilitate chemical reactions more efficiently and dynamically.

Various experimental methods such as FRAP and single molecule microscopy can probe the exchange dynamics of condensates to high resolution. This work aims to develop a theoretical framework to better understand the exchange dynamics of single molecules in LLPS condensates. By incorporating experimental data with coarse-grained molecular dynamics simulations and theory, we demonstrate that the dwell time probability distribution follows a power law with an exponent of -1.5 in the short-time regime, transitioning to an exponential decay in the long-time regime.