Evaluation of the Coupled Two-Dimensional Main Chain Torsional Potential in Modeling Intrinsically Disordered Proteins. 
Intrinsically disordered proteins (IDPs) carry out crucial biological functions in essential biological processes of life.  Because of the highly dynamic and conformationally heterogeneous nature of the disordered states of IDPs, molecular dynamics simulations are becoming an indispensable tool for the investigation of the conformational ensembles and dynamic properties of IDPs.  Nevertheless, there is still no consensus on the most reliable force field in molecular dynamics simulations for IDPs hitherto.  In this work, the recently proposed AMBER99SB2D force field is evaluated in modeling some disordered polypeptides and proteins by checking its ability to reproduce experimental NMR data.  The results highlight that when the ildn side-chain corrections are included, AMBER99SB2D-ildn exhibits reliable results that agree with experiments compared with its predecessors, the AMBER14SB, AMBER99SB, AMBER99SB-ildn, and AMBER99SB2D force fields, and that decreasing the overall magnitude of protein-protein interactions in favor of protein-water interactions is a key ingredient behind the improvement.