Infrared Studies of Aβ Peptides with Copper and Zinc: Linking Interactions with Structural Changes

Abstract

The aggregation of Amyloid-β (Aβ) peptides are known to be influenced by multiple environmental factors. Metals are one factor known to influence the self-assembly of Aβ peptides. Studies have shown that copper and zinc ions are associated with increasing Aβ peptide aggregation and plaque formation as observed in brain slices obtained from Alzheimer's patients. The mechanism of how metal ion interactions with Aβ peptides alters self-assembly and the aggregation state has not yet been fully characterized. However, numerous studies performed under a variety of different experimental conditions have demonstrated metal ion effects on the aggregation of Aβ (40) and Aβ (42). Additional studies performed under identical conditions should allow for better characterization of how copper and zinc uniquely alter the different Aβ peptides aggregation. These studies may provide a greater understanding of metal-induced Aβ aggregation and how metals alter the development of neurodegenerative diseases. Infrared spectroscopy was used to monitor how metals altered Aβ (40) and Aβ (42). Infrared spectra were obtained on both peptides in the presence and absence of metals. The infrared spectra suggest metal-induced structural changes of the Aβ-peptides as compared to control Aβ(40) and Aβ(42) spectra.