A HIGH PERFORMANCE METHOD FOR THERMODYNAMIC STUDY ON THE BINDING OF COPPER ION AND GLYCINE WITH ALZHEIMER'S AMYLOID β PEPTIDE

The interaction of Cu2+ to the first 16 residues of the Alzheimer's amyloid beta peptide, A beta(1-16) was studied by isothermal titration calorimetry at pH 7.2 and 37 degrees C in aqueous solution. The Gholamreza Rezaei Behbehani (GRB) solvation model was used to reproduce the enthalpies of interactions of A beta(1-16) with glycine, Gly+ A beta(1-16), and Cu2+ ions, Cu2++A beta(1-16), over the whole range of Cu2+ concentrations. The binding parameters recovered from the solvation model were attributed to the structural change of A beta(1-16) due to the glycine and Cu2+ interactions. It was found that there is a set of two identical binding sites for Cu2+ ions. p=2 indicates that the binding has positive cooperativity in the two binding sites. A beta(1-16) structure is destabilized greatly as a result of binding to Cu2+ ions.