Model for disordered proteins with strongly sequence-dependent liquid phase behavior. Author Antonia Statt, Helena Casademunt, Clifford Brangwynne, Athanassios Panagiotopoulos Publication Year 2020 Type Journal Article Abstract Phase separation of intrinsically disordered proteins is important for the formation of membraneless organelles or biomolecular condensates, which play key roles in the regulation of biochemical processes within cells. In this work, we investigated the phase separation of different sequences of a coarse-grained model for intrinsically disordered proteins and discovered a surprisingly rich phase behavior. We studied both the fraction of total hydrophobic parts and the distribution of hydrophobic parts. Not surprisingly, sequences with larger hydrophobic fractions showed conventional liquid-liquid phase separation. The location of the critical point was systematically influenced by the terminal beads of the sequence due to changes in interfacial composition and tension. For sequences with lower hydrophobicity, we observed not only conventional liquid-liquid phase separation but also re-entrant phase behavior in which the liquid phase density decreases at lower temperatures. For some sequences, we observed the formation of open phases consisting of aggregates, rather than a normal liquid. These aggregates had overall lower densities than the conventional liquid phases and exhibited complex geometries with large interconnected string-like or membrane-like clusters. Our findings suggest that minor alterations in the ordering of residues may lead to large changes in the phase behavior of the protein, a fact of significant potential relevance for biology. Keywords Models, Molecular, Hydrophobic and Hydrophilic Interactions, Phase Transition, Intrinsically Disordered Proteins Journal J Chem Phys Volume 152 Issue 7 Pages 075101 Date Published 2020 Feb 21 ISSN Number 1089-7690 DOI 10.1063/1.5141095 Alternate Journal J Chem Phys PMID 32087632 PubMedGoogle ScholarBibTeXEndNote X3 XML