Uncovering the role of water in biomolecular liquid-liquid phase separation

The fundamental understanding of the role of hydration water in protein condensation is crucial for tackling protein aggregation-related pathologies such as Alzheimer's, Parkinson's, and cancer. Immunoglobulin G (IgG) is the most common antibody in blood circulation and highly relevant in the pharmaceutical industry. IgG solution in water undergoes LLPS at sub-freezing temperatures, where water plays a crucial role in mediating protein-protein interactions and phase stability. In this regime, the interplay between hydration structure, protein conformations, and phase separation kinetics remains largely unexplored. The purpose of the experiment is to capture the changes in water structure associated with protein nanocluster formation during the early stages of liquid-liquid phase separation (LLPS) and follow the phase separation process.