Tuning Receptor Properties of Metal–Amyloid Beta Complexes. Studies on the Interaction between Ni(II)–Aβ5–9 and Phosphates/Nucleotides

• Published in: Inorganic chemistry 2021-12, Vol.60 (24), p.19448-19456
• Main Authors: Tobolska, Aleksandra, Wezynfeld, Nina E, Wawrzyniak, Urszula E, Bal, Wojciech, Wróblewski, Wojciech
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X; 1520-510X
• DOI: 10.1021/acs.inorgchem.1c03285

Amyloid-beta (Aβ) peptides, potentially relevant in the pathology of Alzheimer’s disease, possess distinctive coordination properties, enabling an effective binding of transition-metal ions, with a preference for Cu­(II). In this work, we found that a N-truncated Aβ analogue bearing a His-2 motif, Aβ5–9, forms a stable Ni­(II) high-spin octahedral complex at a physiological pH of 7.4 with labile coordination sites and facilitates ternary interactions with phosphates and nucleotides. As the pH increased above 9, a spin transition from a high-spin to a low-spin square-planar Ni­(II) complex was observed. Employing electrochemical techniques, we showed that interactions between the binary Ni­(II)–Aβ5–9 complex and phosphate species result in significant changes in the Ni­(II) oxidation signal. Thus, the Ni­(II)–Aβ5–9 complex could potentially serve as a receptor in electrochemical biosensors for phosphate species. The obtained results could also be important for nickel toxicology.