Long-Range Entropic Effects on Protein Intrinsically Disordered Regions

Entropy calculations represent one of the most challenging steps in obtaining the binding free energy in proteins and their complexes, which is a grand challenge in computational biology. In this paper we define the workframe of a novel method to calculate structural entropy for protein molecular simulation : SQuE ( Strucutral Quantifier of Entropy). Using a first degree approximation for the probability distribution, we were able to calculate the entropic effects that emerges from a intrinsically disordered (ID) region in UDP-glucose 6-dehydrogenase (UGDH) protein structure. We were able to quantify the configurational entropy difference in the structured core caused by the truncation of the C-terminal ID-tail, and evaluate the protein conformational changes in the structured domain.