Effects of a Hydrophilic/Hydrophobic Interface on Amyloid-β Peptides Studied by Molecular Dynamics Simulations and NMR Experiments.

Oligomer formation of amyloid-β peptides (Aβ) is accelerated at a hydrophilic/hydrophobic interface. However, details of the acceleration mechanism have not been elucidated. To understand the effects of the interface on oligomerization at the atomic level, we performed molecular dynamics simulations for an Aβ40 monomer in the presence and absence of the hydrophilic/hydrophobic interface. Nuclear magnetic resonance experiments of Aβ40 peptides with gangliosidic micelles were also carried out. In the simulations and experiments, the hydrophobic residues of Aβ40 bound to the interface stably. Moreover, we found that Aβ40 formed a hairpin structure at the interface more readily than in bulk water. From these results, we discussed the acceleration mechanism of the oligomer formation at the interface.