Temperature and Guanidine Hydrochloride Effects on the Folding Thermodynamics of WW Domain and Variants.

We used simulations based on an all-atom Go model to calculate the folding temperatures (Tfs) and free energies (ΔGs) of two variants of the WW domain, which is a small all-β-sheet protein. The results, without adjusting any parameter, are in good agreement with experiments, thus validating the simulations. We then used the molecular transfer model to predict the changes in the ΔGs and Tfs as the guanidine hydrochloride concentration is varied. The predictions can be readily tested in experiments.