Free Energies and Entropies of Binding Sites Identified by MixMD Cosolvent Simulations

J Chem Inf Model. 2019 May 28;59(5):2035-2045. doi: 10.1021/acs.jcim.8b00925. Epub 2019 May 2.

Abstract

In our recent efforts to map protein surfaces using mixed-solvent molecular dynamics (MixMD) (Ghanakota, P.; Carlson, H. A. Moving Beyond Active-Site Detection: MixMD Applied to Allosteric Systems. J. Phys. Chem. B 2016, 120, 8685-8695), we were able to successfully capture active sites and allosteric sites within the top-four most occupied hotspots. In this study, we describe our approach for estimating the thermodynamic profile of the binding sites identified by MixMD. First, we establish a framework for calculating free energies from MixMD simulations, and we compare our approach to alternative methods. Second, we present a means to obtain a relative ranking of the binding sites by their configurational entropy. The theoretical maximum and minimum free energy and entropy values achievable under such a framework along with the limitations of the techniques are discussed. Using this approach, the free energy and relative entropy ranking of the top-four MixMD binding sites were computed and analyzed across our allosteric protein targets: Abl Kinase, Androgen Receptor, Pdk1 Kinase, Farnesyl Pyrophosphate Synthase, Chk1 Kinase, Glucokinase, and Protein Tyrosine Phosphatase 1B.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Binding Sites
  • Entropy*
  • Molecular Dynamics Simulation*
  • Protein Conformation
  • Proteins / chemistry*
  • Solvents / chemistry*

Substances

  • Proteins
  • Solvents