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Updated: Jul 3, 2026

Purification and Refolding to Amyloid Fibrils of (His)6-tagged Recombinant Shadoo Protein Expressed as Inclusion Bodies in E. coli
Published on: December 19, 2015
UV-light exposed prion protein fails to form amyloid fibrils
Abhay Kumar Thakur1, Ch Mohan Rao
1Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, Hyderabad, India.
Abstract:
Amyloid fibril formation involves three steps; structural perturbation, nucleation and elongation. We have investigated amyloidogenesis using prion protein as a model system and UV-light as a structural perturbant. We find that UV-exposed prion protein fails to form amyloid fibrils. Interestingly, if provided with pre-formed fibrils as seeds, UV-exposed prion protein formed amyloid fibrils albeit with slightly different morphology. Atomic force microscopy and electron microscopic studies clearly show the formation of fibrils under these conditions. Circular dichroism study shows loss in helicity in UV-exposed protein. UV-exposed prion protein fails to form amyloid fibrils. However, it remains competent for fibril extension, suggesting that UV-exposure results in loss of nucleating capability. This work opens up possibility of segregating nucleation and elongation step of amyloidogenesis, facilitating screening of new drug candidates for specifically inhibiting either of these processes. In addition, the work also highlights the importance of light-induced structural and functional alterations which are important in protein based therapeutics.
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