THE INTERACTION BETWEEN ALZHEIMER AMYLOID BETA(1-40) PEPTIDE AND GANGLIOSIDE G(M1)-CONTAINING MEMBRANES

The interaction between Alzheimer amyloid peptide A beta(1-40) and mem brane 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 up on binding undergoes a conformational transition from random coil to a n ordered structure rich in beta-sheet. This interaction appears to be ganglioside-specific as no changes in A beta(1-40) conformation mere found in the presence of various phospholipids or sphingomyelin. The i solated oligosaccharide moiety of the ganglioside was ineffective in i nducing alterations in the secondary structure of A beta(1-40), No int eraction,vas observed between ganglioside G(M1) and the N-terminal pep tide fragment A beta(1-28). Binding to the ganglioside is likely to mo dulate the neurotoxic and/or amyloidogenic properties of A beta(1-40).