Simultaneous IR-Spectroscopic Observation of α-Synuclein, Lipids, and Solvent Reveals an Alternative Membrane-Induced Oligomerization Pathway

Chembiochem. 2017 Dec 5;18(23):2312-2316. doi: 10.1002/cbic.201700355. Epub 2017 Nov 2.

Abstract

The intrinsically disordered protein α-synuclein (αS), a known pathogenic factor for Parkinson's disease, can adopt defined secondary structures when interacting with membranes or during fibrillation. The αS-lipid interaction and the implications of this process for aggregation and damage to membranes are still poorly understood. Therefore, we established a label-free infrared (IR) spectroscopic approach to allow simultaneous monitoring of αS conformation and membrane integrity. IR showed its unique sensitivity for identifying distinct β-structured aggregates. A comparative study of wild-type αS and the naturally occurring splicing variant αS Δexon3 yielded new insights into the membrane's capability for altering aggregation pathways.

Keywords: ATR-FTIR; aggregation; alpha-synuclein; protein-membrane interaction; solid-supported lipid bilayers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Kinetics
  • Lipid Bilayers / chemistry
  • Lipid Bilayers / metabolism*
  • Protein Binding
  • Protein Structure, Secondary
  • Solvents / chemistry
  • Spectroscopy, Fourier Transform Infrared*
  • alpha-Synuclein / chemistry
  • alpha-Synuclein / metabolism*

Substances

  • Lipid Bilayers
  • Solvents
  • alpha-Synuclein