Influence of Alzheimer's β-amyloid peptide on the lateral diffusion of lipids in raft-forming bilayers

The effect of added Alzheimer's Aβ(1-40) peptide of the wild type on the lateral diffusion of lipids in macroscopically oriented bilayers of ‘raft’ compositions [a mixture of dioleoylphosphatidylcholine (DOPC), sphingomyelin (SM) and cholesterol (CHOL)] was studied by an NMR-diffusion technique. In homogeneous bilayers, diffusion coefficients decrease, while they change differently in liquid ordered and in liquid disordered phases at varied concentrations of CHOL; this was explained by the decreased maximum solubility of CHOL in phospholipids in the presence of Aβ(1-40) peptide.