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Oligomerization of amyloid Abeta16-22 peptides using hydrogen bonds and hydrophobicity forces.

ABSTRACT: The 16-22 amino-acid fragment of the beta-amyloid peptide associated with the Alzheimer's disease, Abeta, is capable of forming amyloid fibrils. Here we study the aggregation mechanism of Abeta16-22 peptides by unbiased thermodynamic simulations at the atomic level for systems of one, three, and six Abeta16-22 peptides. We find that the isolated Abeta16-22 peptide is mainly a random coil in the sense that both the alpha-helix and beta-strand contents are low, whereas the three- and six-chain systems form aggregated structures with a high beta-sheet content. Furthermore, in agreement with experiments on Abeta16-22 fibrils, we find that large parallel beta-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.

SUBMITTER: Favrin G

PROVIDER: S-EPMC1304880 | biostudies-literature | 2004 Dec

REPOSITORIES: biostudies-literature

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Oligomerization of amyloid Abeta16-22 peptides using hydrogen bonds and hydrophobicity forces.

Favrin Giorgio G Irbäck Anders A Mohanty Sandipan S

Biophysical journal 20040917 6

The 16-22 amino-acid fragment of the beta-amyloid peptide associated with the Alzheimer's disease, Abeta, is capable of forming amyloid fibrils. Here we study the aggregation mechanism of Abeta16-22 peptides by unbiased thermodynamic simulations at the atomic level for systems of one, three, and six Abeta16-22 peptides. We find that the isolated Abeta16-22 peptide is mainly a random coil in the sense that both the alpha-helix and beta-strand contents are low, whereas the three- and six-chain sys ...[more]

PMID: 15377534

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