We choose the GB implicit solvent not only because of
limitations in our resources but also because prior studies
showed that the GB model gives reasonable results for Aβ
variants16,24 and other systems.25,26 One of the limitations of
the implicit solvent is that it ignores the interactions with water.
Therefore, the success of the GB approximation in studying Aβ
thermodynamics16,24 is presumably due to the fact that water
bridges do not contribute significantly to the stability of highly
flexible molecules, such as intrinsically disordered Aβ.16