Temperature dependence of IDPs in simulations: What are we missing?

The temperature dependence of the conformational properties in simulations of the intrinsically disordered model protein Histatin 5 has been investigated using different combinations of force fields, water models, atomistic and coarse-grained methods. The results have been compared to experimental data obtained from NMR, SAXS and CD experiments in order to assess the accuracy and validity of the simulations. The results showed that neither simulations completely agreed with the experimental data, nor did they agree with each other. It was however possible to conclude that the observed conformational changes upon variations in temperature were not at all driven by electrostatic interactions. The final conclusion was that none of the simulations that were investigated in this study was able to accurately capture the temperature induced conformational changes of our model IDP.