Ganglioside Nanocluster-Targeting Peptidyl Inhibitor Prevents Amyloid ? Fibril Formation on the Neuronal Membrane

Neurotoxicity caused by peptide and protein aggregates is associated with the onset of neurodegenerative diseases. Accumulation of the amyloid fi protein (Afi) induced by neuronal ganglioside-enriched nanodomains (nanoclusters) in the presynaptic neuronal membrane, resulting in toxic oligomeric and fibrous forms, is implicated in the onset of Alzheimer's disease (AD). In the current study, we found that the ganglioside clusterbinding peptide (GCBP), a pentadecapeptide VWRLLAPPFSNRLLP that binds to ganglioside-enriched nanoclusters, inhibits the formation of Afi assemblies with an IC50 of 12 pM and also removes Afi fibrils deposited on the lipid membrane. Thus, in addition to inhibiting Afi assembly formation, GCBP effectively clears toxic Afi assemblies as well, thereby suppressing neuronal cellular damage and death induced by such assemblies. These results indicate that ganglioside cluster-binding molecules may act as novel Afi-targeting drugs with a unique mechanism of action that may be utilized to ameliorate AD.