Amyloid Ab40

A three-dimensional reconstruction of Alzheimer's amyloid-b (Ab40) fibril at ~8-Å resolution, obtained using cryo-EM and computer processing of images of fibrils formed in vitro. This fibril contains two protofilaments consisting of the Ab40 peptide, arranged in a b-sheet structure (the so-called cross-b structure). The structure reveals pairing of b-sheets. A second fibril reconstruction is shown in a different orientation and magnification on the right. The background shows an image of Ab fibrils as seen in the electron microscope.

From the labs of Nikolaus Grigorieff and Marcus Fändrich. See also Sachse, C., Fändrich, M., and Grigorieff, N. 2008. PNAS 105:7462–7466.