Human Serum Albumin-Inspired Glycopeptide-Based Multifunctional Inhibitor of Amyloid-β Toxicity

In Alzheimer's disease (AD) insoluble A beta 42 peptide fragments self-aggregate and form oligomers and fibrils in the brain, causing neurotoxicity. Further, the presence of redox-active metal ions such as Cu2+ enhances the aggregation process through chelation with these A beta 42 aggregates as well as generation of A beta 42-mediated reactive oxygen species (ROS). Herein, we have adopted a bioinspired strategy to design and develop a multifunctional glycopeptide hybrid molecule (Glupep), which can serve as a potential AD therapeutic. This molecule consists of a natural metalchelating tetrapeptide motif of human serum albumin (HSA), a beta-sheet breaker peptide, and a sugar moiety for better bioavailability. We performed different biophysical and docking experiments, which revealed that Glupep not only associates with A beta 42 but also prevents its self-aggregation to form toxic oligomers and fibrils. Moreover, Glupep was also shown to sequester out Cu2+ from the A beta-Cu2+ complex, reducing the ROS formation and toxicity. Besides, this study also revealed that Glupep could protect PC12-derived neurons from A beta-Cu2+-mediated toxicity by reducing intracellular ROS generation and stabilizing the mitochondrial membrane potential. All these exciting features show Glupep to be a potent inhibitor of A beta 42-mediated multifaceted toxicity and a prospective therapeutic lead for AD.