Sequence determinants and solution conditions underlying liquid to solid phase transition

Life consists of numberless functional biomolecules that exhibit different phases. When biomolecules cannot fully dissolve in matrices, they can potentially form liquid droplets through liquid-liquid phase separation, especially proteins and nucleic acids. Stronger interactions promote solid-like state of biomolecular condensates, which are also formerly referred as detergent insoluble aggregates. Solid-like condensates exist in vivo physiologically and pathologically and their formation has not been well understood. Recently, more and more researches proved that liquid to solid phase transition is an essential way to form solid condensates. In this review, we mainly focused on the process of liquid to solid phase transition. On the one hand, sequence characteristics influence liquid to solid phase transition of biomolecules greatly and we summarized some of the regions in sequence that have impact on phase transition. Meanwhile, various solution conditions also affect liquid to solid phase transition. We further reviewed the effects that solution conditions including protein concentration, pH etc. have on liquid to solid phase transition. Finally, we introduced established low-throughput experimental techniques and high-throughput omics methods for studying solid phase components.