Wood, Kirstin J. L.;
(2021)
The structural basis of AL amyloidosis.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
KJLWood_ALAmyloidosis_Thesis.pdf - Accepted Version Download (128MB) | Preview |
Abstract
Amyloid light-chain (AL) amyloidosis is a condition where a monoclonal population of plasma cells secrete an abnormally high amount of the light chain portion of an antibody which can deposit as amyloid fibres that obstruct major organs, such as the heart or kidneys. The monoclonal protein is also usually found in the serum and/or urine in sufficient amounts so as to enable purification for structural analysis. This study presents twelve such purified light chains, nine of which produced protein crystals. Four of these yielded diffraction data to resolutions of 1.84-2.30 Å, from which three structures were solved. The first was a λ light chain derived from an AL amyloidosis patient, crystallised in the P212121 space group and giving a final R-factor of 0.2062. The other structures were monomer and dimer forms of a multiple myeloma λ light chain, both crystallising in the C2 space group with final R-factor values of 0.2078 and 0.2028, respectively. When comparing the different forms, small differences were observed in the sequence and conformation of the third hypervariable and second framework region. Light chain proteins were also assessed with circular dichroism to examine their thermal unfolding behaviour, deriving for each a melting temperature and the extent of refolding after denaturation. For six of these, the secondary structure composition and extent of β-sheet unfolding versus temperature were also measured, three of which were analysed in monomer and dimer form. Upon statistical analysis, it appeared that λ light chains refolded to a lesser extent after denaturation. Finally, 2,422 published light chain sequences from the AL-Base database were used to construct three-dimensional models which were searched for potential solvent-accessible clusters of hydrophobic residues. Returned clusters were then assessed for statistically significant differences in frequency, incidence, and location between amyloidogenic and non-amyloidogenic proteins. A higher proportion of amyloidogenic κI and λI light chains were found to contain hydrophobic clusters than non-amyloidogenic ones. Certain clusters were also found to differ in their hydrophobicity for amyloidogenic versus non-amyloidogenic light chains across various subtypes, mainly in the framework regions.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | The structural basis of AL amyloidosis |
| Event: | UCL (University College London) |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2021. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10133833 |
Loading...
Loading...Loading...Loading...Archive Staff Only
 |
View Item |
