A Comparative Interaction between Copper Ions with Alzheimer's β Amyloid Peptide and Human Serum Albumin

Abstract

The interaction of Cu(2+) with the first 16 residues of the Alzheimer's amyliod β peptide, Aβ(1-16), and human serum albumin (HSA) were studied in vitro by isothermal titration calorimetry at pH 7.2 and 310 K in aqueous solution. The solvation parameters recovered from the extended solvation model indicate that HSA is involved in the transport of copper ion. Complexes between Aβ(1-16) and copper ions have been proposed to be an aberrant interaction in the development of Alzheimer's disease, where Cu(2+) is involved in Aβ(1-16) aggregation. The indexes of stability indicate that HSA removed Cu(2+) from Aβ(1-16), rapidly, decreased Cu-induced aggregation of Aβ(1-16), and reduced the toxicity of Aβ(1-16) + Cu(2+) significantly.

Figure 1

Comparison between the experimental heats (O) at 310 K, for HSA + Cu²⁺ interactions and the calculated data (lines) via (1). [Cu²⁺] values are the concentrations of [Cu(NO₃)₂] solution in μM.

Figure 2

Comparison between the experimental heats (O) at 310 K, for Aβ(1–16) + Cu²⁺ interactions and the calculated data (lines) via (1). [Cu²⁺] values are the concentrations of [Cu(NO₃)₂] solution in μM.