Tuning Receptor Properties of Metal-Amyloid Beta Complexes. Studies on the Interaction between Ni(II)-Aβ 5-9 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
• Subjects: Amyloid beta-Peptides - chemistry; Amyloid beta-Peptides - metabolism; Coordination Complexes - chemical synthesis; Coordination Complexes - chemistry; Coordination Complexes - pharmacology; Electrochemical Techniques; Humans; Hydrogen-Ion Concentration; Nickel - chemistry; Nucleotides - chemistry; Phosphates - chemistry
• ISSN: 0020-1669; 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, Aβ , 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)-Aβ complex and phosphate species result in significant changes in the Ni(II) oxidation signal. Thus, the Ni(II)-Aβ complex could potentially serve as a receptor in electrochemical biosensors for phosphate species. The obtained results could also be important for nickel toxicology.