187 -- Investigation of Zinc Metal Ion Effect on Amyloid Beta Protein Structure

Amyloid Beta-Peptide (1-40) is a protein linked to the initial stages of Alzheimer’s and Parkinson’s diseases, with aggregation of this peptide contributing to the development of these diseases. Previous research has revealed favorable attachment of Aβ(1-40) to the surface of gold nanoparticles, with the peptides forming a protein station that is able to interact with other such protein stations in solution. Such a station may be instrumental in creating a device that can attract Aβ(1-40) in humans before a serious degeneration into Alzheimer’s disease occurs. Additionally, some metal cations, such as calcium, copper or zinc, may also interact with amyloidogenic peptides and inhibit further progress in fibrillogenesis, the development of these polypeptide chains that are associated with the neurodegenerative disease. However, no clear studies have yet been conducted on this topic. Consequently, our research group decided to investigate whether the addition of Zn⁺² ions into a solution of Aβ(1-40) and gold nanoparticles had any effect on the aggregation of peptides. Using an experimental procedure whereby the pH of solution was alternated between highly basic and highly acidic, with UV-Vis spectroscopy used to measure the aggregation of peptides, it appears that the Zn⁺² ions do indeed have an effect on the aggregation and folding of these peptides, with the presence of Zn⁺² ions preventing complete reversibility of the folding of Aβ(1-40).