The Position of A beta 22 40 and A beta 1 42 in Anionic Lipid Membranes Containing Cholesterol

Amyloid amp; 946; peptides interact with cell membranes in the human brain and are associated with neurodegenerative diseases, such as Alzheimer s disease. An emerging explanation of the molecular mechanism, which results in neurodegeneration, places the cause of neurotoxicity of the amyloid peptides on their potentially negative interaction with neuronal membranes. It is known that amyloid amp; 946; peptides interact with the membrane, modifying the membrane s structural and dynamic properties. We present a series of X ray diffraction experiments on anionic model lipid membranes containing various amounts of cholesterol. These experiments provide experimental evidence for an interaction of both the full length amyloid amp; 946;1 42 peptide, and the peptide fragment amyloid amp; 946;22 40 with anionic bilayer containing cholesterol. The location of the amyloid amp; 946; peptides was determined from these experiments, with the full length peptide embedding into the membrane, and the peptide fragment occupying 2 positions on the membrane surface and embedded into the membrane cor