Molecular dynamics simulations of amyloid-β(29-42) aggregation in bulk water and at the air-water interface

Oligomers of amyloid-β (Aβ) peptides are related to Alzheimer's disease, and their formation is accelerated at hydrophilic-hydrophobic interfaces. We performed all-atom molecular dynamics simulations of Aβ(29-42) peptides in bulk water and at an air-water interface. In bulk water, the fragments formed stable aggregates, and the secondary structures were hardly changed. At the interface, the peptides were more easily separated from each other due to the low free-energy barrier and changed their secondary structures more frequently. This conformational flexibility is likely to promote amyloid fibril growth, suggesting a key role of interfacial environments in early aggregation processes.