Native Top-Down Mass Spectrometry and Ion Mobility MS for Characterizing the Cobalt and Manganese Metal Binding of α-Synuclein Protein

J Am Soc Mass Spectrom. 2018 Sep;29(9):1870-1880. doi: 10.1007/s13361-018-2002-2. Epub 2018 Jun 27.

Abstract

Structural characterization of intrinsically disordered proteins (IDPs) has been a major challenge in the field of protein science due to limited capabilities to obtain full-length high-resolution structures. Native ESI-MS with top-down MS was utilized to obtain structural features of protein-ligand binding for the Parkinson's disease-related protein, α-synuclein (αSyn), which is natively unstructured. Binding of heavy metals has been implicated in the accelerated formation of αSyn aggregation. Using high-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry, native top-down MS with various fragmentation methods, including electron capture dissociation (ECD), collisional activated dissociation (CAD), and multistage tandem MS (MS3), deduced the binding sites of cobalt and manganese to the C-terminal region of the protein. Ion mobility MS (IM-MS) revealed a collapse toward compacted states of αSyn upon metal binding. The combination of native top-down MS and IM-MS provides structural information of protein-ligand interactions for intrinsically disordered proteins. Graphical Abstract ᅟ.

Keywords: Electron capture dissociation; Electrospray ionization; Metal binding; Native mass spectrometry; Protein-ligand complex; Top-down mass spectrometry; α-Synuclein.

MeSH terms

  • Cobalt / chemistry*
  • Cobalt / metabolism
  • Intrinsically Disordered Proteins / chemistry
  • Intrinsically Disordered Proteins / metabolism
  • Manganese / chemistry*
  • Manganese / metabolism
  • Models, Molecular
  • Spectrometry, Mass, Electrospray Ionization / methods*
  • Tandem Mass Spectrometry / methods
  • alpha-Synuclein / chemistry*
  • alpha-Synuclein / metabolism

Substances

  • Intrinsically Disordered Proteins
  • alpha-Synuclein
  • Cobalt
  • Manganese