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The p3 peptide, a naturally occurring fragment of the amyloid-β peptide (Aβ) found in Alzheimer's disease, has a greater aggregation propensity in vitro than full-length Aβ, but does not bind Cu²⁺

journal contribution
posted on 2000-01-01, 00:00 authored by F Ali, A J Thompson, Colin BarrowColin Barrow
Cerebellar preamyloid from both Down's syndrome and Alzheimer's disease contains the p3 fragment (Aβ17-40/42) as a major amyloid-β peptide (Aβ) component. The p3 peptide was previously shown to form amyloid in vitro, but less readily than full-length Aβ. Here we show that the p3 peptide has a greater β-sheet-forming propensity than full-length Aβ. Using circular dichroism spectroscopy we determined that in aqueous solutions the p3 peptide forms β-sheet structure more readily than full-length Aβ. The p3 peptide also has a lower α-helical propensity than full-length Aβ in the structure-forming solvent trifluoroethanol. These results indicate that the lower amyloidogenicity of the p3 peptide is not related to an inability to form β-sheet structure. In this study we also show that, unlike full-length Aβ, the p3 peptide does not bind Cu 2+ ions. This inability to bind copper ions may explain why the p3 peptide appears to play a lesser role in Down's syndrome and Alzheimer's disease related neurodegeneration than does full-length Aβ.

History

Journal

Australian journal of chemistry

Volume

53

Issue

4

Pagination

321 - 326

Publisher

CSIRO

Location

Clayton, Vic.

ISSN

0004-9425

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2000, CSIRO