Designing a new multifunctional peptide for metal chelation and Aβ inhibition.

According to the Amyloid hypothesis, as the foremost scientific explanation for Alzheimer Disease (AD), the neuropathology of AD is related to toxic fragments of amyloid beta (Aβ) protein. Based on this hypothesis, an attractive therapeutic approach was demonstrated to identify multifunctional peptides able to modulate Aβ pathologies as the source of AD. On this premise, a bifunctional polypeptide based on the iAβ5p lead compound, was designed to inhibit Aβ aggregation and free metal ions. Herein, the efficacy of this novel drug in Zn and Cd ion chelation was examined through an integrated technique comprising combined Docking, QM, and MD simulations. MD relaxation of a set of probable binding modes that were predicted by Molecular Docking, revealed six druggable hosts having considerable affinities. Further, free energy analysis indicated that the formation of the revealed polypeptide-ion complexes is more spontaneous than the presented Aβ-ion ones. These findings certified the new ability of the modified lead compound to hamper Aβ pathologies and provide helpful information in atomic details for further preclinical studies against AD.