Evidence of Redox-Active Iron Formation Following Aggregation of Ferrihydrite and the Alzheimer’s Disease Peptide β-Amyloid

DOI: 10.1021/ic402406g

Authors: James Everett (Keele University) , Eva Céspedes (Keele University) , Leigh Shelford (University of Exeter) , Chris Exley (Keele University) , Joanna Collingwood (Warwick University) , Jon Dobson (Keele University) , Gerrit Van Der Laan (Diamond Light Source) , Catherine A. Jenkins (Lawrence Berkeley National Laboratory) , Elke Arenholz (Lawrence Berkeley National Laboratory) , Neil Telling (Keele University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Inorganic Chemistry , VOL 53 (6) , PAGES 2803−2809

State: Published (Approved)
Published: February 2014
Diamond Proposal Number(s): 7670 , 8731

Abstract: Recent work has demonstrated increased levels of redox-active iron biominerals in Alzheimer’s disease (AD) tissue. However, the origin, nature, and role of iron in AD pathology remains unclear. Using X-ray absorption, X-ray microspectroscopy, and electron microscopy techniques, we examined interactions between the AD peptide β-amyloid (Aβ) and ferrihydrite, which is the ferric form taken when iron is stored in humans. We report that Aβ is capable of reducing ferrihydrite to a pure iron(II) mineral WHERE antiferromagnetically ordered Fe2+ cations occupy two nonequivalent crystal symmetry sites. Examination of these iron(II) phases following air exposure revealed a material consistent with the iron(II)-rich mineral magnetite. These results demonstrate the capability of Aβ to induce the redox-active biominerals reported in AD tissue from natural iron precursors. Such interactions between Aβ and ferrihydrite shed light upon the processes of AD pathogenesis, while providing potential targets for future therapies.

Journal Keywords: Ferrihydrite; Iron; Alzheimer's Disease; Redox-Active; Amyloid Peptide

Subject Areas: Medicine


Instruments: I10-Beamline for Advanced Dichroism

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