2024 AIChE Annual Meeting
(115d) Sequence-Dependent Phase Separation and Aggregation in Model Proteins
Author
Panagiotopoulos, A. - Presenter, Princeton University
Biomolecular phase separation has emerged as an organizing principle underlying subcellular organization and controlling many processes in living systems. The time and length scales relevant for phase transitions of biomolecules far exceed those accessible thought atomistic simulations, so coarse-grained, physics-oriented models are appropriate. A specific principle of molecular organization turns out to be competition between macroscopic phase separation and formation of finite-size aggregates, which is also relevant for micelle formation by surfactants. Recent experiments on synthetic polymers with controlled sequences of solvophobic and solvophilic blocks also display this competition between aggregation and phase separation. In addition, very large, nearly monodisperse equilibrium aggregates are observed at specific thermodynamic conditions in these systems. Grand canonical Monte Carlo simulations shed light on the sequence dependence of the phase separation behavior and point to a novel "surface enrichment" microscopic mechanism for formation of equilibrium aggregates that likely has biological relevance.