scholarly journals Implementation of the QUBE Force Field for High-Throughput Alchemical Free Energy Calculations

Author(s):  
Lauren Nelson ◽  
Sofia Bariami ◽  
Chris Ringrose ◽  
Joshua Horton ◽  
Vadiraj Kurdekar ◽  
...  

<div><div><div><p>The quantum mechanical bespoke (QUBE) force field approach has been developed to facilitate the automated derivation of potential energy function parameters for modelling protein-ligand binding. To date the approach has been validated in the context of Monte Carlo simulations of protein-ligand complexes. We describe here the implementation of the QUBE force field in the alchemical free energy calculation molecular dynamics simulation package SOMD. The implementation is validated by computing relative binding free energies for two congeneric series of non-nucleoside inhibitors of HIV-1 reverse transcriptase using QUBE and AMBER/GAFF force fields. The availability of QUBE in a modern simulation package that makes efficient use of GPU acceleration will greatly facilitate future high-throughput alchemical free energy calculation studies.</p></div></div></div>

2020 ◽  
Author(s):  
Lauren Nelson ◽  
Sofia Bariami ◽  
Chris Ringrose ◽  
Joshua Horton ◽  
Vadiraj Kurdekar ◽  
...  

<div><div><div><p>The quantum mechanical bespoke (QUBE) force field approach has been developed to facilitate the automated derivation of potential energy function parameters for modelling protein-ligand binding. To date the approach has been validated in the context of Monte Carlo simulations of protein-ligand complexes. We describe here the implementation of the QUBE force field in the alchemical free energy calculation molecular dynamics simulation package SOMD. The implementation is validated by computing relative binding free energies for two congeneric series of non-nucleoside inhibitors of HIV-1 reverse transcriptase using QUBE and AMBER/GAFF force fields. The availability of QUBE in a modern simulation package that makes efficient use of GPU acceleration will greatly facilitate future high-throughput alchemical free energy calculation studies.</p></div></div></div>


2021 ◽  
Author(s):  
Lauren Nelson ◽  
Sofia Bariami ◽  
Chris Ringrose ◽  
Joshua Horton ◽  
Vadiraj Kurdekar ◽  
...  

<div><div><div><p>The quantum mechanical bespoke (QUBE) force field approach has been developed to facilitate the automated derivation of potential energy function parameters for modelling protein-ligand binding. To date the approach has been validated in the context of Monte Carlo simulations of protein-ligand complexes. We describe here the implementation of the QUBE force field in the alchemical free energy calculation molecular dynamics simulation package SOMD. The implementation is validated by demonstrating the reproducibility of absolute hydration free energies computed with the QUBE force field across the SOMD and GROMACS software packages. We further demonstrate, by way of a case study involving two series of non-nucleoside inhibitors of HIV-1 reverse transcriptase, that the availability of QUBE in a modern simulation package that makes efficient use of GPU acceleration will facilitate high-throughput alchemical free energy calculations.</p></div></div></div>


2021 ◽  
Author(s):  
Si Zhang ◽  
David Hahn ◽  
Michael R. Shirts ◽  
Vincent Voelz

<p>Alchemical free energy methods have become indispensable in computational drug discovery for their ability to calculate highly accurate estimates of protein-ligand affinities. Expanded ensemble (EE) methods, which involve single simulations visiting all of the alchemical intermediates, have some key advantages for alchemical free energy calculation. However, there have been relatively few examples published in the literature of using expanded ensemble simulations for free energies of protein-ligand binding. In this paper, as a test of expanded ensemble methods, we computed relative binding free energies using the Open Force Field Initiative force field (codename “Parsley”) for twenty-four pairs of Tyk2 inhibitors derived from a congeneric series of 16 compounds. The EE predictions agree well with the experimental values (RMSE of 0.94 ± 0.13 kcal mol<sup>−1</sup> and MUE of 0.75 ± 0.12 kcal mol<sup>−1</sup>). We find that while increasing the number of alchemical intermediates can improve the phase space overlap, faster convergence can be obtained with fewer intermediates, as long as the acceptance rates are sufficient. We find that convergence can be improved using more aggressive updating of the biases, and that estimates can be improved by performing multiple independent EE calculations. This work demonstrates that EE is a viable option for alchemical free energy calculation. We discuss the implications of these findings for rational drug design, as well as future directions for improvement.</p>


2021 ◽  
Author(s):  
Si Zhang ◽  
David Hahn ◽  
Michael R. Shirts ◽  
Vincent Voelz

<p>Alchemical free energy methods have become indispensable in computational drug discovery for their ability to calculate highly accurate estimates of protein-ligand affinities. Expanded ensemble (EE) methods, which involve single simulations visiting all of the alchemical intermediates, have some key advantages for alchemical free energy calculation. However, there have been relatively few examples published in the literature of using expanded ensemble simulations for free energies of protein-ligand binding. In this paper, as a test of expanded ensemble methods, we computed relative binding free energies using the Open Force Field Initiative force field (codename “Parsley”) for twenty-four pairs of Tyk2 inhibitors derived from a congeneric series of 16 compounds. The EE predictions agree well with the experimental values (RMSE of 0.94 ± 0.13 kcal mol<sup>−1</sup> and MUE of 0.75 ± 0.12 kcal mol<sup>−1</sup>). We find that while increasing the number of alchemical intermediates can improve the phase space overlap, faster convergence can be obtained with fewer intermediates, as long as the acceptance rates are sufficient. We find that convergence can be improved using more aggressive updating of the biases, and that estimates can be improved by performing multiple independent EE calculations. This work demonstrates that EE is a viable option for alchemical free energy calculation. We discuss the implications of these findings for rational drug design, as well as future directions for improvement.</p>


RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19623-19629
Author(s):  
Vinay S. Kandagal ◽  
Jennifer M. Pringle ◽  
Maria Forsyth ◽  
Fangfang Chen

The free energy calculation shows the different free energy changes of the adsorption and absorption of gas molecules into an organic ionic plastic crystal, successfully predicting the gas selectivity of this new type of gas separation material.


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