Zn induced structural aggregation patterns of β-amyloid peptides by first-principle simulations and XAS measurements

Metallomics. 2012 Feb;4(2):156-65. doi: 10.1039/c2mt00148a. Epub 2011 Dec 15.

Abstract

We show in this paper that in the presence of Zn ions a peculiar structural aggregation pattern of β-amyloid peptides in which metal ions are sequentially coordinated to either three or four histidines of nearby peptides is favored. To stabilize this configuration a deprotonated imidazole ring from one of the histidines forms a bridge connecting two adjacent Zn ions. Though present in zeolite imidazolate frameworks, remarkably in biological compounds this peculiar Zn-imidazolate-Zn topology is only found in enzymes belonging to the Cu,Zn-superoxide dismutase family in the form of an imidazolate bridging Cu and Zn. The results we present are obtained by combining X-ray absorption spectroscopy experimental data with detailed first-principle molecular dynamics simulations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / chemistry*
  • Amyloid beta-Peptides / metabolism
  • Histidine / chemistry
  • Imidazoles / chemistry
  • Molecular Dynamics Simulation
  • X-Ray Absorption Spectroscopy
  • Zinc / chemistry*

Substances

  • Amyloid beta-Peptides
  • Imidazoles
  • Histidine
  • imidazole
  • Zinc