Amyloid-beta-copper interaction studied by simultaneous nitrogen K and copper L_{2,3 -}edge soft X-ray absorption spectroscopy.

ABSTRACT: We study the interaction between amyloid β (Aβ) peptides and Cu and Zn metal ions by using soft X-ray absorption spectroscopy. The spectral features of the peptides and Cu are simultaneously characterized by recording spectra at the N K-edge and at the Cu L_{2,3 -}edges. In the presence of the peptides, the Cu L_{2,3 -}edge shows a fingerprint of monovalent Cu(I), caused by the interaction with the peptides. The appearance of Cu(I) is less significant at an acidic pH than at a basic pH. Furthermore, aggregation leads to a smaller signature of Cu(I). N K-edge spectra reveal that Cu and Zn ions exhibit a different coordination with the nitrogen atoms in the peptides. This suggests different roles of Cu and Zn in the peptide aggregation. Our work provides

SUBMITTER: Luo J 

PROVIDER: S-EPMC8710549 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature