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Structural characterisation of islet amyloid polypeptide fibrils
journal contribution
posted on 2023-06-07, 21:31 authored by O Sumner Makin, Louise SerpellLouise SerpellIslet amyloid is found in many patients suffering from type 2 diabetes. Amyloid fibrils found deposited in the pancreatic islets are composed of a 37-residue peptide, known as islet amyloid polypeptide (IAPP) (also known as amylin) and are similar to those found in other amyloid diseases. Synthetic IAPP peptide readily forms amyloid fibrils in vitro and this has allowed fibril formation kinetics and the overall morphology of IAPP amyloid to be studied. Here, we use X-ray fibre diffraction, electron microscopy and cryo-electron microscopy to examine the molecular structure of IAPP amyloid fibrils. X-ray diffraction from aligned synthetic amyloid fibrils gave a highly oriented diffraction pattern with layer-lines spaced 4.7 Å apart. Electron diffraction also revealed the characteristic 4.7 Å meridional signal and the position of the reflection could be compared directly to the image of the diffracting unit. Cryo-electron microscopy revealed the strong signal at 4.7 Å that has been previously visualised from a single Aß fibre. Together, these data build up a picture of how the IAPP fibril is held together by hydrogen bonded ß-sheet structure and contribute to the understanding of the generic structure of amyloid fibrils.
History
Publication status
- Published
Journal
Journal of Molecular BiologyISSN
0022-2836External DOI
Issue
5Volume
335Page range
1279-1288Pages
10.0Department affiliated with
- Biochemistry Publications
Notes
LS is the corresponding author and wrote the paper. OSM is a student who co-authored and did the analysis. The paper describes the structural analysis of amyloid fibrils formed in Diabetes type 2.Full text available
- No
Peer reviewed?
- Yes