Cu²⁺ and Zn²⁺ -induced aggregation of amyloid-β peptide

To study the effect of Cu²⁺ and Zn²⁺ on amyloid-β peptides (Αβ) aggregation, the morphology, size and cell toxicity of Aβ40 aggregates formed with the metal ions have been observed by the methods including ultraviolet spectroscopy, fluorescence spectroscopy and transmission electron microscopy.  The results showed that Cu²⁺ and Zn²⁺ can accelerate Aβ40 aggregation, and both changed the morphology and size of Aβ40 aggregates.  Zn²⁺ induced Aβ40 to form fibrous Aβ40 aggregates, while the amorphous and fibrous aggregates were produced by the interaction between Cu²⁺ and Aβ40.  In addition, H₂O₂ was produced when Aβ40 reduced Cu²⁺.  The relationship between metal ions and Aβ40 aggregates was analyzed, and the function of metal ions in Alzheimer’s disease (AD) was illustrated in the research.