Transition Metal Ion Interactions with Disordered Amyloid-β Peptides in the Pathogenesis of Alzheimer's Disease: Insights from Computational Chemistry Studies

Monomers and oligomers of the amyloid-beta peptide aggregate to form the fibrils found in the brains of Alzheimer's disease patients. These monomers and oligomers are largely disordered and can interact with transition metal ions, affecting the mechanism and kinetics of amyloid-beta aggregation. Due to the disordered nature of amyloid-beta, its rapid aggregation, as well as solvent and paramagnetic effects, experimental studies face challenges in the characterization of transition metal ions bound to amyloid-beta monomers and oligomers. The details of the coordination chemistry between transition metals and amyloid-beta obtained from experiments remain debated. Furthermore, the impact of transition metal ion binding on the monomeric or oligomeric amyloid-beta structures and dynamics are still poorly understood. Computational chemistry studies can serve as an important complement to experimental studies and can provide additional knowledge on the binding between amyloid-beta and transition metal ions. Many research groups conducted first-principles calculations, ab initio molecular dynamics simulations, quantum mechanics/classical mechanics simulations, and classical molecular dynamics simulations for studying the interplay between transition metal ions and amyloid-beta monomers and oligomers. This review summarizes the current understanding of transition metal interactions with amyloid-beta obtained from computational chemistry studies. We also emphasize the current view of the coordination chemistry between transition metal ions and amyloid-beta. This information represents an important foundation for future metal ion chelator and drug design studies aiming to combat Alzheimer's disease.