AmyP53 Prevents the Formation of Neurotoxic β-Amyloid Oligomers through an Unprecedent Mechanism of Interaction with Gangliosides: Insights for Alzheimer's Disease Therapy

A broad range of data identify Ca2+-permeable amyloid pores as the most neurotoxic species of Alzheimer's beta-amyloid peptide (A beta(1-42)). Following the failures of clinical trials targeting amyloid plaques by immunotherapy, a consensus is gradually emerging to change the paradigm, the strategy, and the target to cure Alzheimer's disease. In this context, the therapeutic peptide AmyP53 was designed to prevent amyloid pore formation driven by lipid raft microdomains of the plasma membrane. Here, we show that AmyP53 outcompetes A beta(1-42) binding to lipid rafts through a unique mode of interaction with gangliosides. Using a combination of cellular, physicochemical, and in silico approaches, we unraveled the mechanism of action of AmyP53 at the atomic, molecular, and cellular levels. Molecular dynamics simulations (MDS) indicated that AmyP53 rapidly adapts its conformation to gangliosides for an optimal interaction at the periphery of a lipid raft, where amyloid pore formation occurs. Hence, we define it as an adaptive peptide. Our results describe for the first time the kinetics of AmyP53 interaction with lipid raft gangliosides at the atomic level. Physicochemical studies and in silico simulations indicated that A beta(1-42) cannot interact with lipid rafts in presence of AmyP53. These data demonstrated that AmyP53 prevents amyloid pore formation and cellular Ca2+ entry by competitive inhibition of A beta(1-42) binding to lipid raft gangliosides. The molecular details of AmyP53 action revealed an unprecedent mechanism of interaction with lipid rafts, offering innovative therapeutic opportunities for lipid raft and ganglioside-associated diseases, including Alzheimer's, Parkinson's, and related proteinopathies.

Automated summary

Various data indicate that Ca2+-permeable amyloid pores are the most neurotoxic species of Alzheimer's beta-amyloid peptide (A beta(1-42)). As clinical trials targeting amyloid plaques by immunotherapy have failed, there is growing consensus to change the paradigm, strategy, and target for curing Alzheimer's disease. In this study, a therapeutic peptide called AmyP53 was developed to prevent amyloid pore formation by interacting with gangliosides in lipid rafts. Through a combination of cellular, physicochemical, and in silico approaches, the mechanism of action of AmyP53 at the atomic, molecular, and cellular levels was unraveled. It was found that AmyP53 outcompetes A beta(1-42) in binding to lipid rafts and prevents amyloid pore formation and cellular Ca2+ entry. These findings provide insights into the molecular details of AmyP53 action and offer potential therapeutic opportunities for lipid raft and ganglioside-associated diseases.