Stabilization of α-synuclein oligomers using formaldehyde

PLoS One. 2019 Oct 11;14(10):e0216764. doi: 10.1371/journal.pone.0216764. eCollection 2019.

Abstract

The group of neurodegenerative diseases, Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA) all exhibit inclusions containing amyloid-type α-synuclein (α-syn) aggregates within degenerating brain cells. α-syn also exists as soluble oligomeric species that are hypothesized to represent intermediates between its native and aggregated states. These oligomers are present in brain extracts from patients suffering from synucleinopathies and hold great potential as biomarkers. Although easily prepared in vitro, oligomers are metastable and dissociate over time, thereby complicating α-syn oligomer research. Using the small amine-reactive cross-linker, formaldehyde (FA), we successfully stabilized α-syn oligomers without affecting their size, overall structure or antigenicity towards aggregate-conformation specific α-syn antibodies FILA and MJFR-14-6-4-2. Further, cross-linked α-syn oligomers show resistance towards denaturant like urea and SDS treatment and remain fully functional as internal standard in an aggregation-specific enzyme-linked immunosorbent assay (ELISA) despite prior incubation with urea. We propose that FA cross-linked α-syn oligomers could serve as important calibrators to facilitate comparative and standardized α-syn biomarker studies going forward.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid / chemistry*
  • Amyloid / metabolism
  • Formaldehyde / chemistry*
  • Humans
  • Lewy Body Disease / metabolism
  • Multiple System Atrophy / metabolism
  • Parkinson Disease / metabolism
  • Protein Multimerization*
  • Protein Stability
  • alpha-Synuclein / chemistry*
  • alpha-Synuclein / metabolism

Substances

  • Amyloid
  • SNCA protein, human
  • alpha-Synuclein
  • Formaldehyde

Grant support

This work was supported by Michael J Fox (https://www.michaeljfox.org/) grant 13750 and Lundbeck foundation (https://www.lundbeckfonden.com/) grants R223-2015-4222, R248-2016-25, R248-2016-2518 (Dandrite) that funded all aspects of the study to PHJ. The funders did not participate in study design, data collection and analysis, decision to publish, or preparation of the manuscript.