Atomic-level investigations on the amyloid-β dimerization process and its driving forces in water.

We report the spontaneous dimerization process of the full-length Aβ42 proteins in water by using unguided, fully atomistic, explicit-water molecular dynamics simulations. Based on the thermodynamic analysis, we demonstrate that Aβ42 dimerization in water occurs via a two-step nucleation-accommodation mechanism driven by water-induced force and by protein internal force, respectively.