Fiber diffraction data indicate a hollow core for the Alzheimer's a? 3-fold symmetric fibril.

ABSTRACT: Amyloid ? protein (A?), the principal component of the extracellular plaques found in the brains of patients with Alzheimer's disease, forms fibrils well suited to structural study by X-ray fiber diffraction. Fiber diffraction patterns from the 40-residue form A?(1-40) confirm a number of features of a 3-fold symmetric A? model from solid-state NMR (ssNMR) but suggest that the fibrils have a hollow core not present in the original ssNMR models. Diffraction patterns calculated from a revised 3-fold hollow model with a more regular ?-sheet structure are in much better agreement with the observed diffraction data than patterns calculated from the original ssNMR model. Refinement of a hollow-core model against ssNMR data led to a revised ssNMR model, similar to the fiber diffraction model.

SUBMITTER: McDonald M 

PROVIDER: S-EPMC3462308 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature