Single-Molecule Two-Color Coincidence Detection of Unlabeled alpha-Synuclein Aggregates

Angew Chem Int Ed Engl. 2023 Apr 3;62(15):e202216771. doi: 10.1002/anie.202216771. Epub 2023 Feb 28.

Abstract

Protein misfolding and aggregation into oligomeric and fibrillar structures is a common feature of many neurogenerative disorders. Single-molecule techniques have enabled characterization of these lowly abundant, highly heterogeneous protein aggregates, previously inaccessible using ensemble averaging techniques. However, they usually rely on the use of recombinantly-expressed labeled protein, or on the addition of amyloid stains that are not protein-specific. To circumvent these challenges, we have made use of a high affinity antibody labeled with orthogonal fluorophores combined with fast-flow microfluidics and single-molecule confocal microscopy to specifically detect α-synuclein, the protein associated with Parkinson's disease. We used this approach to determine the number and size of α-synuclein aggregates down to picomolar concentrations in biologically relevant samples.

Keywords: Aggregation or Oligomerization; Fluorescence; Microscopy; Proteins; Single-Molecule.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid / chemistry
  • Amyloidogenic Proteins
  • Humans
  • Parkinson Disease* / metabolism
  • Protein Aggregates
  • alpha-Synuclein* / chemistry

Substances

  • alpha-Synuclein
  • Protein Aggregates
  • Amyloid
  • Amyloidogenic Proteins