Wydział Chemii

Teresa Kowalik-Jankowska

Monika Ruta

K. Wiśniewska

L. Łankiewicz

2003

Journal of Inorganic Biochemistry

95

270-282

10.1016/S0162-0134(03)00128-4

Naukowa

Angielski

Artykuł

Stoichiometry, stability constants and solution structures of the copper(II) complexes of the (1–16H), (1–28H), (1–16M), (1–28M), (Ac-1–16H) and (Ac-1–16M) fragments of human (H) and mouse (M) β-amyloid peptide were determined in aqueous solution in the pH range 2.5–10.5. The potentiometric and spectroscopic data (UV–Vis, CD, EPR) show that acetylation of the amino terminal group induces significant changes in the coordination properties of the (Ac-1–16H) and (Ac-1–16M) peptides compared to the (1–16H) and (1–16M) fragments, respectively. The (Ac-1–16H) peptide forms the 3N {N_Im⁶, N_Im¹³, N_Im¹⁴} complex in a wide pH range (5–8), while for the (Ac-1–16M) fragment the 2N {N_Im⁶, N_Im¹⁴} complex in the pH range 5–7 is suggested. At higher pH values sequential amide nitrogens are deprotonated and coordinated to copper(II) ions. The N-terminal amino group of the (1–16) and (1–28) fragments of human and mouse β-amyloid peptide takes part in the coordination of the metal ion, although, at pH above 9 the complexes with the 4N {N_Im, 3N⁻} coordination mode are formed. The phenolate –OH group of the Tyr¹⁰ residue of the human fragments does not coordinate to the metal ion.

β-Amyloid peptide fragments, Alzheimer’s disease, Copper(II) complexes, Stability constants, Spectroscopic studies

https://doi.org/10.1016/S0162-0134(03)00128-4

http://www.elsevier.com