Cosolvent effects on the growth of amyloid fibrils.

Cells are equipped with cosolvents that modulate protein folding and aggregation to withstand water stress. The effect of cosolvents on the aggregation rates depends on whether the polypeptide sequence is an intrinsically disordered protein (IDP) or can fold into a specific native structure. Cosolvents, which act as denaturants generally slow down aggregation in IDPs, while expediting it in globular proteins. In contrast, protecting osmolytes facilitate aggregation in IDPs, while slowing it down in globular proteins. In this review we highlight the recent computational approaches to gain insight into the role of cosolvents on the aggregation mechanism of IDPs and globular proteins. Computer simulations using the molecular transfer model, which implements the cosolvent effects in coarse-grained protein models in conjunction with enhanced sampling techniques played an important role in elucidating the effect of cosolvents on the growth of amyloid fibrils.