The Stability of Amyloid Fibrils - a case study on a-synuclein

Research Project, 2021 – 2024

Amyloid fibrils are associated with a great variety of human diseases, including neurodegenerative conditions such as Parkinson’s disease (PD). Whilst much is known about the kinetics and mechanisms by which amyloid fibrils form, less attention has been paid to their stabilities and modes of disintegration. Using the PD protein a-synuclein (a-syn) as model, this project aims to explore the molecular origin and magnitude of the stability of amyloid fibrils and to relate this to their biological activities.Fibril stability will be explored from a thermodynamic viewpoint using chemical denaturants and biochemical methods. Potentially synergistic destabilizing factors such as fragmentation and limited proteolysis will be explored. Using mutational analysis and published structural data, we will define stability hotspots within the a-syn sequences, arguing how these could be important targets for future stability-modifying therapies.We will also develop a nanofluidic method to study the rates and mechanisms of depolymerization of individual fibrils in solution, exploring the concept of fibril polymorphism. A fluorescent reporter cell line will be generated to image a-syn uptake, endosome rupture, and seeding reactions, modelling key events in prion-like propagation. The project will offer new fundamental insights into the molecular underpinnings of PD that may be important for future therapeutic development towards mitigating the aggregation and cell-cell propagation of a-syn.