
==== Front
bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.09.09.612142
preprint
1
Article
In cell NMR reveals cells selectively amplify and structurally remodel amyloid fibrils
Ansari Shoyab http://orcid.org/0009-0009-0446-528X

Lagasca Dominique http://orcid.org/0000-0003-4404-4366

Dumarieh Rania http://orcid.org/0000-0002-4462-7134

Xiao Yiling http://orcid.org/0000-0002-4548-4833

Krishna Sakshi http://orcid.org/0000-0002-4223-0379

Li Yang http://orcid.org/0000-0001-9601-4885

Frederick Kendra K. http://orcid.org/0000-0002-1656-5167

10 9 2024
2024.09.09.612142https://creativecommons.org/licenses/by-nc-nd/4.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which allows reusers to copy and distribute the material in any medium or format in unadapted form only, for noncommercial purposes only, and only so long as attribution is given to the creator.
http://biorxiv.org/lookup/doi/10.1101/2024.09.09.612142
nihpp-2024.09.09.612142.pdf
Abstract

Amyloid forms of α-synuclein adopt different conformations depending on environmental conditions. Advances in structural biology have accelerated fibril characterization. However, it remains unclear which conformations predominate in biological settings because current methods typically not only require isolating fibrils from their native environments, but they also do not provide insight about flexible regions. To address this, we characterized α-syn amyloid seeds and used sensitivity enhanced nuclear magnetic resonance to investigate the amyloid fibrils resulting from seeded amyloid propagation in different settings. We found that the amyloid fold and conformational preferences of flexible regions are faithfully propagated in vitro and in cellular lysates. However, seeded propagation of amyloids inside cells led to the minority conformation in the seeding population becoming predominant and more ordered, and altered the conformational preferences of flexible regions. The examination of the entire ensemble of protein conformations in biological settings that is made possible with this approach may advance our understanding of protein misfolding disorders and facilitate structure-based drug design efforts.
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pmc
