The structural study of copper-binding peptides: Implication in the aggregation of amyloid-β peptides

There is evidence that copper is bound to amyloid-β peptide (Aβ) in senile plaque of Alzheimer's disease. Copper also plays a role in the neurotoxicity of the Aβ aggregates associated with free radical damage. In this study, we used L-histidyl-L-histidine peptide (di-histidine) to represent Aβ along with ab initio calculation to characterize the probable coordination between Cu(II) and Aβs to explore the Aβ aggregate structures. Sixteen models of copper-di-histidine complexes were proposed to investigate the copper-induced aggregation of Aβs through copper ionic coordination. All structures of the proposed models were optimized at the M05-2X/LanL2DZ level, and an Aβ aggregation formation mechanism was proposed.