A Capped Peptide of the Aggregation Prone NAC 71–82 Amino Acid Stretch of α-Synuclein Folds into Soluble β-Sheet Oligomers at Low and Elevated Peptide Concentrations

Although Lewy bodies and Lewy neurites are hallmarks of Parkinson’s disease (PD) and dementia with Lewy bodies (DLB), misfolded α-synuclein oligomers are nowadays believed to be key for the development of these diseases. Attempts to target soluble misfolded species of the full-len...

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Bibliographic Details
Main Authors: Thomas Näsström, Jörgen Ådén, Fumina Shibata, Per Ola Andersson, Björn C.G. Karlsson
Format: Article
Language:English
Published: MDPI AG 2020-02-01
Series:International Journal of Molecular Sciences
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Online Access:https://www.mdpi.com/1422-0067/21/5/1629
Description
Summary:Although Lewy bodies and Lewy neurites are hallmarks of Parkinson’s disease (PD) and dementia with Lewy bodies (DLB), misfolded α-synuclein oligomers are nowadays believed to be key for the development of these diseases. Attempts to target soluble misfolded species of the full-length protein have been limited so far, probably due to the fast aggregation kinetics and burial of aggregation prone segments in final cross-β-sheet fibrils. A previous characterisation study of fibrils prepared from a capped peptide of the non-amyloid β-component (NAC) 71−82 amino acid stretch of α-synuclein demonstrated an increased aggregation propensity resulting in a cross-β-structure that is also found in prion proteins. From this, it was suggested that capped NAC 71−82 peptide oligomers would provide interesting motifs with a capacity to regulate disease development. Here, we demonstrated, from a series of circular dichroism spectroscopic measurements and molecular dynamics simulations, the molecular-environment-sensitive behaviour of the capped NAC 71−82 peptide in a solution phase and the formation of β-sheet oligomeric structures in the supernatant of a fibrillisation mixture. These results highlighted the use of the capped NAC 71−82 peptide as a motif in the preparation of oligomeric β-sheet structures that potentially could be used in therapeutic strategies in the fight against progressive neurodegenerative disorders, such as PD and DLB.
ISSN:1422-0067