Spectroscopic investigations on metal coordination to amyloid‐β

Abstract Alzheimer's disease (AD) is a complex neurodegenerative disorder marked by progressive cognitive decline and neuronal loss. A key pathological hallmark of AD is the accumulation and aberrant aggregation of amyloid‐β (Aβ) peptides, which contributes to synaptic dysfunction and neurotoxicity. While the aggregation behavior of Aβ has been extensively studied, it can be altered by various factors, particularly metal ions, such as Fe(II/III), Cu(I/II), and Zn(II). These metal ions directly interact with specific amino acid residues in Aβ, influencing its oligomerization, fibrillization, and capacity to generate reactive oxygen species, thereby exacerbating oxidative stress and accelerating disease progression. Understanding the coordination chemistry between metal ions and Aβ is critical for deciphering their pathological impact in AD. This review provides a comprehensive overview of metal‐bound Aβ (metal–Aβ) coordination at the molecular level, with a focus on insights gained from advanced spectroscopic methods. Nuclear magnetic resonance, electron paramagnetic resonance, and x‐ray absorption spectroscopies collectively illuminate metal‐binding sites, coordination geometries, and dynamic structural behavior of metal–Aβ complexes. These complementary approaches enable detailed structural characterization and mechanistic understanding of metal‐induced Aβ aggregation and toxicity. By integrating spectroscopic findings on Fe(II/III), Cu(I/II), and Zn(II) coordination to Aβ, we highlight their distinct roles in AD pathogenesis as well as the broader significance of metal–peptide interactions underlying the mechanisms of neurodegenerative diseases.