Structural Comparison of Mouse and Human α-Synuclein Amyloid Fibrils by Solid-State NMR

Abstract

Fibrillar α-synuclein (AS) is the major component of Lewy bodies, the pathological hallmark of Parkinson's disease. Mouse AS (mAS) aggregates much faster than human AS (hAS), although mAS differs from hAS at only seven positions in its primary sequence. Currently, little is known about the site-specific structural differences between mAS and hAS fibrils. Here, we applied state-of-the-art solid-state nuclear magnetic resonance (ssNMR) methods to structurally characterize mAS fibrils. The assignment strategy employed a set of high-resolution 2D and 3D ssNMR spectra recorded on uniformly [(13)C, (15)N], [1-(13)C]glucose, and [2-(13)C]glucose labeled mAS fibrils. An almost complete resonance assignment (96% of backbone amide (15)N and 93% of all (13)C nuclei) was obtained for residues from Gly41 to Val95, which form the core of mAS fibrils. Six β-strands were identified to be within the fibril core of mAS based on a secondary chemical shift and NHHC analysis. Intermolecular (13)C:(15)N labeled restraints obtained from mixed 1:1 (13)C/(15)N-labeled mAS fibrils reveal a parallel, in-register supramolecular β-sheet arrangement. The results were compared in detail to recent structural studies on hAS fibrils and indicate the presence of a structurally conserved motif comprising residues Glu61-Lys80.

β-Helical architecture of cytoskeletal bactofilin filaments revealed by solid-state NMR

“…This is in large part due to the spontaneous formation, inertness, and insolubility of bactofilin polymers, which makes them difficult substrates for crystallography studies as well as conventional liquid-state NMR methods. We therefore resorted to the use of solid-state NMR (ssNMR) spectroscopy, a technique that has recently been adapted to obtain high-resolution structural information on insoluble and noncrystalline protein assemblies, including functional oligomeric assemblies (15)(16)(17), disease-related amyloid fibrils (18)(19)(20)(21), and membrane proteins in a lipid bilayer environment (22)(23)(24)(25)(26). In this study, we have applied state-of-theart magic-angle spinning ssNMR spectroscopy in combination with a range of other biophysical methods to filaments of the C. crescentus bactofilin BacA (161 residues).…”

Spontaneous Aggregation of the Insulin-Derived Steric Zipper Peptide VEALYL Results in Different Aggregation Forms with Common Features

“…Hence, the elucidation of individual structural polymorphs on an atomic level is challenging and the conclusions drawn so far are still controversial [26][27][28]. Obtaining structural constraints for models of full-length amyloid peptides and proteins beyond the molecular level proves to be a major task and requires considerable effort in designing suitable experimental protocols and the use of state-of-the-art instrumentation [9,29,30,10,11,31].…”

The structure of fibrils from ‘misfolded’ proteins

“…Putative b-sheet are given in black arrows. (a)[21]; (b)[20]; (c)[15]; (d)[22 ]; (e)[23 ]. d and e show similar b-sheet distribution, and are probably closely related polymorphs, even if e is from mouse a-synuclein.fragments of the protein.…”