Abstract
Protein aggregation and amyloidosis are linked to many neurodegenerative diseases as well as rare inherited disorders. Parkinson’s disease in particular, is caused by Lewy bodies – amyloid fibril aggregates of α-synuclein that induce the apoptosis of neuron cells. Although the general amyloid pathway of α-synuclein aggregation has been explored, in-depth structural and kinetic data during each step of aggregation, from monomeric protein to fibrils and propagation, is yet to be fully studied. Due to the disordered nature of α-synuclein monomers and the transient nature of oligomers, the ability to structurally model them has been limited in detail with past techniques such as NMR, CD and light scattering.Despite the current focus on oligomeric aspects of α-synuclein in therapeutics, the seeded aggregation pathway and its prion-like spreading continue to be a crucial area of study. It is evident that the aggregation pathway as a whole should be considered for protein amyloid therapeutics, as each stage is an important conduit to each other, and drug targets can be found at any stage of the aggregation process.
However, the constant shift in polydispersity, structure and size during protein aggregation makes it a challenging topic to explore with existing techniques. In the case of α-synuclein, the protein molecule will go through oligomeric, fibril and seeding stages, and even different conformations in the presence or absence of lipids.
There has been a gap in the area of amyloids to offer real-time structural data and kinetics in a combined fashion, as well as in-depth structural analysis for disordered monomers and transient oligomers. In this thesis, we aimed to fill the gap in research by using cutting-edge small-angle scattering techniques combined with structural modelling.
Chapter 4 and 5 of this thesis will explore the monomeric and oligomeric forms of α-synuclein using SEC-SAXS from Diamond Light Source. Chapter 6 will focus on developing SAXS techniques to study the seeded aggregation pathway of α-synuclein. And finally, Chapter 7 will explore the challenging topic of vesicle induced aggregation using the contrast matching technique of small angle neutron scattering. We hope the thesis will provide the reader novel insights into the aggregation of α-synuclein and illustrate the potential usage of these scattering techniques for other protein aggregation studies.
| Date of Award | 28 Jun 2023 |
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| Original language | English |
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| Supervisor | Jody Mason (Supervisor) & Adam Squires (Supervisor) |