The interaction of Aβ42 peptide in monomer, oligomer or fibril forms with sphingomyelin/cholesterol/ganglioside bilayers

Aβ42 peptide binds neuronal membranes and aggregates into plaques that are characteristic of Alzheimer's disease. has been proposed to be generated in membrane (nano) domains the liquid-ordered phase, ganglioside GM1 being a major facilitator binding membrane. The exists solution various degrees aggregation, either monomers, oligomers or fibrils, which appear particularly toxic. present study reports on peptide, monomer, oligomer fibril form, model (lipid vesicles monolayers), composed sphingomyelin cholesterol equimolar ratios, 1–5 mol% different gangliosides were incorporated. Thermodynamic parameters obtained from calorimetric data indicate strong tendency bind (ΔG ≈ 7 kcal/mol peptide), process dominated most cases by increase entropy. ΔG was virtually invariant with species aggregation state peptide. Langmuir balance demonstrated capacity all preparations become inserted lipid monolayers any composition initial π range 10–30 mN/m, although fibrils less capable do so than their maximum ≈25 mN/m.