Download MendeleyCryo-EM structure of islet amyloid polypeptide fibrils reveals similarities with amyloid-beta fibrils.
Roder, C., Kupreichyk, T., Gremer, L., Schafer, L.U., Pothula, K.R., Ravelli, R.B.G., Willbold, D., Hoyer, W., Schroder, G.F.(2020) Nat Struct Mol Biol 27: 660-667
- PubMed: 32541895
- DOI: https://doi.org/10.1038/s41594-020-0442-4
- Primary Citation of Related Structures:
6Y1A - PubMed Abstract:
Amyloid deposits consisting of fibrillar islet amyloid polypeptide (IAPP) in pancreatic islets are associated with beta-cell loss and have been implicated in type 2 diabetes (T2D). Here, we applied cryo-EM to reconstruct densities of three dominant IAPP fibril polymorphs, formed in vitro from synthetic human IAPP. An atomic model of the main polymorph, built from a density map of 4.2-Å resolution, reveals two S-shaped, intertwined protofilaments. The segment 21-NNFGAIL-27, essential for IAPP amyloidogenicity, forms the protofilament interface together with Tyr37 and the amidated C terminus. The S-fold resembles polymorphs of Alzheimer's disease (AD)-associated amyloid-β (Aβ) fibrils, which might account for the epidemiological link between T2D and AD and reports on IAPP-Aβ cross-seeding in vivo. The results structurally link the early-onset T2D IAPP genetic polymorphism (encoding Ser20Gly) with the AD Arctic mutation (Glu22Gly) of Aβ and support the design of inhibitors and imaging probes for IAPP fibrils.
Organizational Affiliation:
Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany.
