Johansson, Jan
- Institutionen för molekylär biovetenskap, Sveriges lantbruksuniversitet
Sammanfattning
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.
Nyckelord
x-ray diffraction; side-chain packing; structure; pi,pi bonding; beta-sheet interaction
Publicerad i
Proceedings of the National Academy of Sciences
2005, volym: 102, nummer: 2, sidor: 315-320
Utgivare: NATL ACAD SCIENCES
SLU författare
UKÄ forskningsämne
Molekylärbiologi
Publikationens identifierare
- DOI: https://doi.org/10.1073/pnas.0406847102
Permanent länk till denna sida (URI)
https://res.slu.se/id/publ/5673