title: Verification of the C-terminal intramolecular beta-sheet in Abeta42 aggregates using solid-state NMR: implications for potent neurotoxicity through the formation of radicals.
abstract: Structural analysis of 42-residue amyloid beta (Abeta42) aggregates using rotational resonance in solid-state NMR verified that C(beta) and/or C(gamma) of Met-35 and the carboxyl carbon of Ala-42 are proximal enough to form an intramolecular antiparallel beta-sheet in the C-terminus. The S-oxidized radical cation at Met-35, an ultimate radical species responsible for neurotoxicity, could be stabilized by the carboxylate anion at the C-terminus, resulting in aggregation to cause long-term oxidative stress.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Masuda
authors.forename: Satoko
authors.initials: S
authors.lastname: Uemura
authors.forename: Azusa
authors.initials: A
authors.lastname: Nakanishi
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Ohashi
authors.forename: K
authors.initials: K
authors.lastname: Takegoshi
authors.forename: Takahiko
authors.initials: T
authors.lastname: Shimizu
authors.forename: Takuji
authors.initials: T
authors.lastname: Shirasawa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Irie
mesh_terms: D000409:Alanine / Q000737:chemistry; D000544:Alzheimer Disease / Q000209:etiology*; D016229:Amyloid beta-Peptides / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D008715:Methionine / Q000737:chemistry; D008954:Models, Biological; D008958:Models, Molecular; D020258:Neurotoxicity Syndromes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D018384:Oxidative Stress / Q000502:physiology; D010446:Peptide Fragments / Q000737:chemistry*; D017433:Protein Structure, Secondary
chemical_list: D016229:Amyloid beta-Peptides; D005609:Free Radicals; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D008715:Methionine; D000409:Alanine