title: Intermolecular alignment in Y145Stop human prion protein amyloid fibrils probed by solid-state NMR spectroscopy.
abstract: The Y145Stop mutant of human prion protein, huPrP23-144, has been linked to PrP cerebral amyloid angiopathy, an inherited amyloid disease, and also serves as a valuable in vitro model for investigating the molecular basis of amyloid strains. Prior studies of huPrP23-144 amyloid by magic-angle-spinning (MAS) solid-state NMR spectroscopy revealed a compact β-rich amyloid core region near the C-terminus and an unstructured N-terminal domain. Here, with the focus on understanding the higher-order architecture of huPrP23-144 fibrils, we probed the intermolecular alignment of β-strands within the amyloid core using MAS NMR techniques and fibrils formed from equimolar mixtures of (15)N-labeled protein and (13)C-huPrP23-144 prepared with [1,3-(13)C(2)] or [2-(13)C]glycerol. Numerous intermolecular correlations involving backbone atoms observed in 2D (15)N-(13)C spectra unequivocally suggest an overall parallel in-register alignment of the β-sheet core. Additional experiments that report on intermolecular (15)N-(13)CO and (15)N-(13)Cα dipolar couplings yielded an estimated strand spacing that is within ∼10% of the distances of 4.7-4.8 Å typical for parallel β-sheets.
authors.affiliation: Department of Chemistry, The Ohio State University, Columbus, 43210, United States.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Helmus
authors.forename: Krystyna
authors.initials: K
authors.lastname: Surewicz
authors.forename: Marcin I
authors.initials: MI
authors.lastname: Apostol
authors.forename: Witold K
authors.initials: WK
authors.lastname: Surewicz
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Jaroniec
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry* / Q000235:genetics*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D011328:Prions / Q000737:chemistry* / Q000235:genetics*; D017433:Protein Structure, Secondary
chemical_list: D000682:Amyloid; D011328:Prions