Phase behavior of mixtures of polyampholytic proteins and RNA: a toy model study

Sammanfattning: Biomolecular condensates are aggregates formed from liquid-liquid phase separation through the interactions between nucleic acids and multivalent proteins. These condensates are essential for many biochemical processes inside the cell. Therefore, there has been a large effort during the last decade to create models and methods to describe these systems. Mixtures of RNA and proteins are very common in nature, making it conceivable that RNA-protein interactions are important in many biomolecular condensates. In this thesis these biomolecules are modeled as simple chains of charged beads. First, one- and two-component protein systems are investigated, with results that are consistent with previous findings made by other groups. RNA was then added to few different one-component protein systems. It was found that the presence of a few RNA molecules increases the aggregation propensity in the sense that aggregation sets in at a higher temperature. When the amount of RNA in the system was increased past a certain threshold, this trend was reverted.