Molecular basis for amyloid fibril formation and stability.

ABSTRACT: The molecular structure of the amyloid fibril has remained elusive because of the difficulty of growing well diffracting crystals. By using a sequence-designed polypeptide, we have produced crystals of an amyloid fiber. These crystals diffract to high resolution (1 A) by electron and x-ray diffraction, enabling us to determine a detailed structure for amyloid. The structure reveals that the polypeptides form fibrous crystals composed of antiparallel beta-sheets in a cross-beta arrangement, characteristic of all amyloid fibers, and allows us to determine the side-chain packing within an amyloid fiber. The antiparallel beta-sheets are zipped together by means of pi-bonding between adjacent phenylalanine rings and salt-bridges between charge pairs (glutamic acid-lysine), thus controlling and

SUBMITTER: Makin OS 

PROVIDER: S-EPMC544296 | biostudies-literature | 2005 Jan

REPOSITORIES: biostudies-literature