title: Observation of highly flexible residues in amyloid fibrils of the HET-s prion.
abstract: We report the observation of undetected (until now) residues of the prion protein fragment HET-s(218-289) which give rise to well-resolved (13)C, (15)N, and (1)H NMR resonances under high-resolution magic-angle spinning (HRMAS) conditions. The observed signals belong to large polymeric units as shown by measuring the lateral diffusion constants. The amino acids identified in the spectra are compatible with their localization in the segments of the protein which could not be detected in earlier solid-state NMR experiments. The observed chemical shifts indicate that these residues are in a random-coil conformation. Complementary experiments which detect only dynamic or static residues, respectively, strongly suggest that they belong to different parts of the same molecule.
authors.affiliation: Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland.
authors.forename: Ansgar B
authors.initials: AB
authors.lastname: Siemer
authors.forename: Alexandre A
authors.initials: AA
authors.lastname: Arnold
authors.forename: Christiane
authors.initials: C
authors.lastname: Ritter
authors.forename: Thomas
authors.initials: T
authors.lastname: Westfeld
authors.forename: Matthias
authors.initials: M
authors.lastname: Ernst
authors.forename: Roland
authors.initials: R
authors.lastname: Riek
authors.forename: Beat H
authors.initials: BH
authors.lastname: Meier
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010446:Peptide Fragments / Q000737:chemistry*; D011328:Prions / Q000737:chemistry*
chemical_list: D000682:Amyloid; D005656:Fungal Proteins; C083891:HET-S protein, Podospora anserina; D010446:Peptide Fragments; D011328:Prions