Volume 5 Supplement 1

8th German Conference on Chemoinformatics: 26 CIC-Workshop

Open Access

Is the novel amyloid-β tetramer fold a stable conformation?

Journal of Cheminformatics20135(Suppl 1):P10

https://doi.org/10.1186/1758-2946-5-S1-P10

Published: 22 March 2013

In the pathogenesis of Alzheimer's disease (AD), the most common neurodegenerative disorder, the amyloid-β (Aβ) peptide plays a key role. Originally, the Aβ fibrils were postulated to be the neurotoxic agents for a long time, because an increased presence of extracellular amyloid plaques, composed primarily of insoluble Aβ fibrils, is found in the brain of affected patients. Recent studies, however, showed a higher cytotoxicity for small Aβ oligomers than for the Aβ fibrils so that these soluble Aβ oligomers are moving to the centre of interest now [1, 2].

Because of the unstable and noncrystalline nature of these species, obtaining structural information for small oligomers is an experimentally challenging task. Novel structural insight was obtained from a recent crystal structure of a tetramer formed by the amyloidogenic residues 18-41 of the Aβ peptide. To enhance stability, this fragment was genetically engineered into the CDR3 loop region of a shark Ig single variable domain antibody [3].

Since the respective crystal structure is stabilized by the antibody moiety, we investigated, whether the respective topology also represents a stable fold for the isolated Aβ-peptide.

We performed molecular dynamics simulations in explicit solvent for the isolated tetrameric amyloid-β fragment in two different lengths (17-40 and 17-42) and the derived dimer and monomer structures. In contrast to Aβ17-40, we observed a stable dynamical behaviour for the tetramer of Aβ17-42: the extension of the antiparallel β-sheet through the residues 41 and 42 is responsible for the enhanced structural stability.

In summary, our results suggest that the novel tetrameric structure represents a stable oligomer conformation for the longer and more neurotoxic Aβ42 species and thus could be a new target in rational drug design aiming at the prevention of toxic oligomer formation.

Authors’ Affiliations

(1)
Bioinformatik, Friedrich-Alexander-Universität Erlangen-Nürnberg

References

  1. Haass C, Selkoe DJ: Soluble protein oligomers in neurodegeneration: lessons from the Alzheimer's amyloid beta-peptide. Nat Rev Mol Cell Biol. 2007, 8: 101-112. 10.1038/nrm2101.View ArticleGoogle Scholar
  2. Stroud JC, Liu C, Teng PK, Eisenberg D: Toxic fibrillar oligomers of amyloid-β have cross-β structure. PNAS. 2012, 109: 7717-7722. 10.1073/pnas.1203193109.View ArticleGoogle Scholar
  3. Streltsov VA, Varghese JN, Masters CL, Nuttall SD: Crystal structure of the amyloid-β p3 fragment provides a model for oligomer formation in Alzheimer's disease. J Neurosci. 2011, 31: 1419-1426. 10.1523/JNEUROSCI.4259-10.2011.View ArticleGoogle Scholar

Copyright

© Socher et al.; licensee BioMed Central Ltd. 2013

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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