The interaction between Alzheimer amyloid β(1–40) peptide and ganglioside G M1-containing membranes

Abstract

The interaction between Alzheimer amyloid peptide Aβ(1–40) and membrane lipids was studied by circular dichroism spectroscopy under the conditions of physiologically relevant ionic strength and neutral pH. The peptide binds to the membranes containing ganglioside G M1 and upon binding undergoes a conformational transition from random coil to an ordered structure rich in β-sheet. This interaction appears to be ganglioside-specific as no changes in Aβ(1–40) conformation were found in the presence of various phospholipids or sphingomyelin. The isolated oligosaccharide moiety of the ganglioside was ineffective in inducing alterations in the secondary structure of Aβ(1–40). No interaction was observed between ganglioside G M1 and the N-terminal peptide fragment Aβ(1–28). Binding to the ganglioside is likely to modulate the neurotoxic and/or amyloidogenic properties of Aβ(1–40).