title: Structure and texture of fibrous crystals formed by Alzheimer's abeta(11-25) peptide fragment.
abstract: Amyloid fibril deposition is central to the pathology of Alzheimer's disease. X-ray diffraction from amyloid fibrils formed from full-length Abeta(1-40) and from a shorter fragment, Abeta(11-25), have revealed cross-beta diffraction fingerprints. Magnetic alignment of Abeta(11-25) amyloid fibrils gave a distinctive X-ray diffraction texture, allowing interpretation of the diffraction data and a model of the arrangement of the peptides within the amyloid fiber specimen to be constructed. An intriguing feature of the structure of fibrillar Abeta(11-25) is that the beta sheets, of width 5.2 nm, stack by slipping relative to each other by the length of two amino acid units (0.70 nm) to form beta ribbons 4.42 nm in thickness. Abeta(1-40) amyloid fibrils likely consist of once-folded hairpins, consistent with the size of the fibers obtained using electron microscopy and X-ray diffraction.
authors.affiliation: Physics Department, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.
authors.forename: Pawel
authors.initials: P
authors.lastname: Sikorski
authors.forename: Edward D T
authors.initials: ED
authors.lastname: Atkins
authors.forename: Louise C
authors.initials: LC
authors.lastname: Serpell
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000737:chemistry* / Q000648:ultrastructure; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D006801:Humans; D008280:Magnetics; D008956:Models, Chemical; D008958:Models, Molecular; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments