Executive Summary : | Chaperone proteins, such as hsp40, hsp60, hsp70, and small hsps, stabilize unstructured proteins in cells, preventing aggregation. However, under pathological conditions, some proteins, such as intrinsically disordered proteins (IDPs), form unstable protein structures, leading to the formation of toxic amyloid fibrils. These proteins undergo phase separation, forming viscous droplets that mature into insoluble aggregates. These droplets can recruit drugs, peptides, or proteins, which can either accelerate or inhibit aggregation. Inhibiting aggregation is crucial for treatment. This proposal aims to examine the phase separation phenomenon associated with chaperone proteins, which stabilize unstructured polypeptides (UPs) and prevent aggregation. Using hsps with a long unstructured domain, such as hsp70, the disordered region consists of approximately 30-40 amino acids. The study will examine phase separation in the presence of macromolecular crowding agents and optimize protein and salt concentrations. The study will also monitor the recruitment of amyloid peptides into condensates and their aggregation kinetics using Thioflavin T assay, turbidity assay based on spectroscopic techniques, and imaging using confocal microscopy and TEM. The conformational dynamics of chaperone proteins and unstructured polypeptides will be obtained at the molecular level using optical tweezer-based surface tension and viscosity measurement. |