Johansson, Jan
- Department of Molecular Biosciences, Swedish University of Agricultural Sciences
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 Angstrom) 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 stabilizing the structure. These interactions are likely to be important in the formation and stability of other amyloid fibrils.
Keywords
x-ray diffraction; side-chain packing; structure; pi,pi bonding; beta-sheet interaction
Published in
Proceedings of the National Academy of Sciences
2005, volume: 102, number: 2, pages: 315-320
Publisher: NATL ACAD SCIENCES
SLU Authors
UKÄ Subject classification
Molecular Biology
Publication identifier
- DOI: https://doi.org/10.1073/pnas.0406847102
Permanent link to this page (URI)
https://res.slu.se/id/publ/5673