Book excerpt: The effects of cosolutes on protein stability were further studied using simulations of a simple "HP" protein in the presence of solute molecules that are devoid of enthalpic interactions. It was found that entropic interactions were able to account for the increase in stability of our model protein as well as the exclusion of solute molecules from the protein surface. This simulation study also examined the impact of cosolute size and shape on its ability to stabilize the native state of the model protein.