|
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
|