Thermodynamic Characterisation of Amyloid Fibrils

Amyloid fibril related diseases include dementia, Alzheimer’s disease and Parkinsons disease and pose an increasingly large burden to global healthcare, due to the presence of an ageing population. Despite many healthcare advances, amyloid fibril diseases remain largely untreatable, with only symptom managements available rather than any disease-modifying treatments. With hundreds of potential drug candidates failing clinical trials, this suggests that something is lacking in current approaches. One such gap is the thermodynamics of amyloid fibrils and how clinical agents modify the stability of fibrils, either positively or negatively. Thus far there has been a focus on the kinetic stability of amyloid fibrils due to the development and availability of kinetic assays. Specifically, the use of Thioflavin-T (ThT) fluorescence monitored growth curves to quantify the kinetics of amyloid growth in a robust, high-throughput manner. The equivalent thermodynamic assays are largely underdeveloped and as such remain underutilised. This thesis aims to fill this gap by developing a thermodynamic assay which can be used to quantify the Gibbs Free Energy (ΔG), enthalpy (ΔH), entropy (ΔS) and heat capacity (ΔCp) of amyloid fibril elongation. The development of this assay is detailed in Chapter 3, with the accompanying fitting script developed in Chapter 4. The assay was developed to be highly accessible in order to promote its uptake and use, with a low resource burden and a high throughput. The application of this assay to amyloid fibril systems is then detailed in chapter 5. Finally, development of a drug screening platform for use in identifying molecules which could modify the thermodynamic stability of amyloid fibrils is investigated in chapter 6. Through this thesis the development of an assay to quantify the thermodynamic stability of amyloid fibrils is described, with the stability of lysozyme, α-synuclein, insulin, tau, silk and amyloid-β fibrils investigated.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2021

Author dc:creator

• Callaghan, Kimberley Laura

Advisors dc:contributor.advisor

• Knowles, Tuomas PJ
• Dobson, Christopher M

• Amyloid
• Amyloid Fibrils
• Thermodynamics
• Gibbs Free Energy
• Assay Development
• Dementia

Licence

• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

eng

DOI dc:identifier.doi

https://doi.org/10.17863/CAM.82240

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/334808