Giorgio Favrin, Anders Irbäck and Sandipan Mohanty
Oligomerization of Amyloid Aβ(16-22) Peptides Using Hydrogen Bonds and Hydrophobicity Forces
Biophysical Journal 87, 3657-3664 (2004); erratum 89, 754 (2005)

Abstract
The 16-22 amino acid fragment of the β-amyloid peptide associated with the Alzheimer's disease, Aβ, is capable of forming amyloid fibrils. Here we study the aggregation mechanism of Aβ(16-22) peptides by unbiased thermodynamic simulations at the atomic level for systems of one, three and six Aβ(16-22) peptides. We find that the isolated Aβ(16-22) peptide is mainly a random coil in the sense that both the α-helix and β-strand contents are low, whereas the three- and six-chain systems form aggregated structures with a high β-sheet content. Furthermore, in agreement with experiments on Aβ(16-22) fibrils, we find that large parallel β-sheets are unlikely to form. For the six-chain system, the aggregated structures can have many different shapes, but certain particularly stable shapes can be identified.

LU TP 04-18