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

• Published in: Journal of the American Society for Mass Spectrometry 2018-09, Vol.29 (9), p.1870-1880
• Main Authors: Wongkongkathep, Piriya, Han, Jong Yoon, Choi, Tae Su, Yin, Sheng, Kim, Hugh I., Loo, Joseph A.
• Format: Article
• Language: English
• Subjects: alpha-Synuclein - chemistry; alpha-Synuclein - metabolism; Analytical Chemistry; Beta decay; Binding sites; Biochemistry & Molecular Biology; Bioinformatics; Biotechnology; Chemistry; Chemistry and Materials Science; Cobalt; Cobalt - chemistry; Cobalt - metabolism; Cyclotron resonance; Electron capture; Focus: Application of Photons and Radicals for MS: Research Article; Fourier transforms; Heavy metals; High resolution; Intrinsically Disordered Proteins - chemistry; Intrinsically Disordered Proteins - metabolism; Ionic mobility; Ions; Ligands; Manganese; Manganese - chemistry; Manganese - metabolism; Mass spectrometry; Models, Molecular; Organic Chemistry; Parkinson's disease; Proteins; Proteomics; Scientific imaging; Spectrometry, Mass, Electrospray Ionization - methods; Spectroscopy; Structural analysis; Tandem Mass Spectrometry - methods
• ISSN: 1044-0305; 1879-1123
• DOI: 10.1007/s13361-018-2002-2

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 (MS 3 ), 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