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Amezcua M, Setiadi J, Mobley DL. The SAMPL9 host-guest blind challenge: an overview of binding free energy predictive accuracy. Phys Chem Chem Phys 2024; 26:9207-9225. [PMID: 38444308 PMCID: PMC10954238 DOI: 10.1039/d3cp05111k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 02/03/2024] [Indexed: 03/07/2024]
Abstract
We report the results of the SAMPL9 host-guest blind challenge for predicting binding free energies. The challenge focused on macrocycles from pillar[n]-arene and cyclodextrin host families, including WP6, and bCD and HbCD. A variety of methods were used by participants to submit binding free energy predictions. A machine learning approach based on molecular descriptors achieved the highest accuracy (RMSE of 2.04 kcal mol-1) among the ranked methods in the WP6 dataset. Interestingly, predictions for WP6 obtained via docking tended to outperform all methods (RMSE of 1.70 kcal mol-1), most of which are MD based and computationally more expensive. In general, methods applying force fields achieved better correlation with experiments for WP6 opposed to the machine learning and docking models. In the cyclodextrin-phenothiazine challenge, the ATM approach emerged as the top performing method with RMSE less than 1.86 kcal mol-1. Correlation metrics of ranked methods in this dataset were relatively poor compared to WP6. We also highlight several lessons learned to guide future work and help improve studies on the systems discussed. For example, WP6 may be present in other microstates other than its -12 state in the presence of certain guests. Machine learning approaches can be used to fine tune or help train force fields for certain chemistry (i.e. WP6-G4). Certain phenothiazines occupy distinct primary and secondary orientations, some of which were considered individually for accurate binding free energies. The accuracy of predictions from certain methods while starting from a single binding pose/orientation demonstrates the sensitivity of calculated binding free energies to the orientation, and in some cases the likely dominant orientation for the system. Computational and experimental results suggest that guest phenothiazine core traverses both the secondary and primary faces of the cyclodextrin hosts, a bulky cationic side chain will primarily occupy the primary face, and the phenothiazine core substituent resides at the larger secondary face.
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Affiliation(s)
- Martin Amezcua
- Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, California 92697, USA.
| | - Jeffry Setiadi
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, USA
| | - David L Mobley
- Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, California 92697, USA.
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, USA
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2
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Jaffrelot Inizan T, Plé T, Adjoua O, Ren P, Gökcan H, Isayev O, Lagardère L, Piquemal JP. Scalable hybrid deep neural networks/polarizable potentials biomolecular simulations including long-range effects. Chem Sci 2023; 14:5438-5452. [PMID: 37234902 PMCID: PMC10208042 DOI: 10.1039/d2sc04815a] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 04/03/2023] [Indexed: 07/28/2023] Open
Abstract
Deep-HP is a scalable extension of the Tinker-HP multi-GPU molecular dynamics (MD) package enabling the use of Pytorch/TensorFlow Deep Neural Network (DNN) models. Deep-HP increases DNNs' MD capabilities by orders of magnitude offering access to ns simulations for 100k-atom biosystems while offering the possibility of coupling DNNs to any classical (FFs) and many-body polarizable (PFFs) force fields. It allows therefore the introduction of the ANI-2X/AMOEBA hybrid polarizable potential designed for ligand binding studies where solvent-solvent and solvent-solute interactions are computed with the AMOEBA PFF while solute-solute ones are computed by the ANI-2X DNN. ANI-2X/AMOEBA explicitly includes AMOEBA's physical long-range interactions via an efficient Particle Mesh Ewald implementation while preserving ANI-2X's solute short-range quantum mechanical accuracy. The DNN/PFF partition can be user-defined allowing for hybrid simulations to include key ingredients of biosimulation such as polarizable solvents, polarizable counter ions, etc.… ANI-2X/AMOEBA is accelerated using a multiple-timestep strategy focusing on the model's contributions to low-frequency modes of nuclear forces. It primarily evaluates AMOEBA forces while including ANI-2X ones only via correction-steps resulting in an order of magnitude acceleration over standard Velocity Verlet integration. Simulating more than 10 μs, we compute charged/uncharged ligand solvation free energies in 4 solvents, and absolute binding free energies of host-guest complexes from SAMPL challenges. ANI-2X/AMOEBA average errors are discussed in terms of statistical uncertainty and appear in the range of chemical accuracy compared to experiment. The availability of the Deep-HP computational platform opens the path towards large-scale hybrid DNN simulations, at force-field cost, in biophysics and drug discovery.
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Affiliation(s)
- Théo Jaffrelot Inizan
- Sorbonne Université, Laboratoire de Chimie Théorique UMR 7616 CNRS Paris 75005 France
| | - Thomas Plé
- Sorbonne Université, Laboratoire de Chimie Théorique UMR 7616 CNRS Paris 75005 France
| | - Olivier Adjoua
- Sorbonne Université, Laboratoire de Chimie Théorique UMR 7616 CNRS Paris 75005 France
| | - Pengyu Ren
- Department of Biomedical Engineering, University of Texas at Austin Austin Texas USA
| | - Hatice Gökcan
- Department of Chemistry, Carnegie Mellon University Pittsburgh Pennsylvania USA
| | - Olexandr Isayev
- Department of Chemistry, Carnegie Mellon University Pittsburgh Pennsylvania USA
| | - Louis Lagardère
- Sorbonne Université, Laboratoire de Chimie Théorique UMR 7616 CNRS Paris 75005 France
- Sorbonne Université, Institut Parisien de Chimie Physique et Théorique FR 2622 CNRS Paris France
| | - Jean-Philip Piquemal
- Sorbonne Université, Laboratoire de Chimie Théorique UMR 7616 CNRS Paris 75005 France
- Department of Biomedical Engineering, University of Texas at Austin Austin Texas USA
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3
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Chung MKJ, Miller RJ, Novak B, Wang Z, Ponder JW. Accurate Host-Guest Binding Free Energies Using the AMOEBA Polarizable Force Field. J Chem Inf Model 2023; 63:2769-2782. [PMID: 37075788 PMCID: PMC10878370 DOI: 10.1021/acs.jcim.3c00155] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
A grand challenge of computational biophysics is accurate prediction of interactions between molecules. Molecular dynamics (MD) simulations have recently gained much interest as a tool to directly compute rigorous intermolecular binding affinities. The choice of a fixed point-charge or polarizable multipole force field used in MD is a topic of ongoing discussion. To compare alternative methods, we participated in the SAMPL7 and SAMPL8 Gibb octaacid host-guest challenges to assess the Atomic Multipole Optimized Energetics for Biomolecular Applications (AMOEBA) polarizable multipole force field. Advantages of AMOEBA over fixed charge models include improved representation of molecular electrostatic potentials and better description of water occupying the unligated host cavity. Prospective predictions for 26 host-guest systems exhibit a mean unsigned error vs experiment of 0.848 kcal/mol across all absolute binding free energies, demonstrating excellent agreement between computational and experimental results. In addition, we explore two topics related to the inclusion of ions in MD simulations: use of a neutral co-alchemical protocol and the effect of salt concentration on binding affinity. Use of the co-alchemical method minimally affects computed energies, but salt concentration significantly perturbs our binding results. Higher salt concentration strengthens binding through classical charge screening. In particular, added Na+ ions screen negatively charged carboxylate groups near the binding cavity, thereby diminishing repulsive coulomb interactions with negatively charged guests. Overall, the AMOEBA results demonstrate the accuracy available through a force field providing a detailed energetic description of the four octaacid hosts and 13 charged organic guests. Use of the AMOEBA polarizable atomic multipole force field in conjunction with an alchemical free energy protocol can achieve chemical accuracy in application to realistic molecular systems.
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Affiliation(s)
- Moses K. J. Chung
- Medical Scientist Training Program, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Physics, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - Ryan J. Miller
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - Borna Novak
- Medical Scientist Training Program, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Zhi Wang
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - Jay W. Ponder
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO 63130, USA
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63110, USA
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4
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Yang X, Liu C, Kuo YA, Yeh HC, Ren P. Computational study on the binding of Mango-II RNA aptamer and fluorogen using the polarizable force field AMOEBA. Front Mol Biosci 2022; 9:946708. [PMID: 36120549 PMCID: PMC9478177 DOI: 10.3389/fmolb.2022.946708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Fluorescent light-up aptamers (FLAPs) are well-performed biosensors for cellular imaging and the detection of different targets of interest, including RNA, non-nucleic acid molecules, metal ions, and so on. They could be easily designed and emit a strong fluorescence signal once bound to specified fluorogens. Recently, one unique aptamer called Mango-II has been discovered to possess a strong affinity and excellent fluorescent properties with fluorogens TO1-Biotin and TO3-Biotin. To explore the binding mechanisms, computational simulations have been performed to obtain structural and thermodynamic information about FLAPs at atomic resolution. AMOEBA polarizable force field, with the capability of handling the highly charged and flexible RNA system, was utilized for the simulation of Mango-II with TO1-Biotin and TO3-Biotin in this work. The calculated binding free energy using published crystal structures is in excellent agreement with the experimental values. Given the challenges in modeling complex RNA dynamics, our work demonstrates that MD simulation with a polarizable force field is valuable for understanding aptamer-fluorogen binding and potentially designing new aptamers or fluorogens with better performance.
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Affiliation(s)
- Xudong Yang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Chengwen Liu
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Yu-An Kuo
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Hsin-Chih Yeh
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States
- Texas Materials Institute, University of Texas at Austin, Austin, TX, United States
| | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States
- Oden Institute for Computational Engineering and Science, Austin, TX, United States
- Interdisciplinary Life Science Graduate Programs, Austin, TX, United States
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5
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Song Y, Lee S, Bell D, Goudey B, Zhou R. Binding Affinity Calculations of Gluten Peptides to HLA Risk Modifiers: DQ2.5 versus DQ7.5. J Phys Chem B 2022; 126:5151-5160. [PMID: 35796490 DOI: 10.1021/acs.jpcb.2c00962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Free energy perturbation (FEP) calculations can predict relative binding affinities of an antigen and its point mutants to the same human leukocyte antigen (HLA) with high accuracy (e.g., within 1.0 kcal/mol to experiment); however, a more challenging task is to compare binding affinities of wholly different antigens binding to completely different HLAs using FEP. Researchers have used a variety of different FEP schemes to compute and compare absolute binding affinities, with varied success. Here, we propose and assess a unifying scheme to compute the relative binding affinities of different antigens binding to completely different HLAs using absolute binding affinity FEP calculations. We apply our affinity calculation technique to HLA-antigen-T-cell receptor (TCR) systems relevant to celiac disease (CeD) by investigating binding affinity differences between HLA-DQ2.5 (enhanced CeD risk) and HLA-DQ7.5 (CeD protective) in the binary (HLA-gliadin) and ternary (HLA-gliadin-TCR) binding complexes for three gliadin derived epitopes: glia-α1, glia-α2, and glia-ω1. Based on FEP calculations with our carefully designed thermodynamic cycles, we demonstrate that HLA-DQ2.5 has higher binding affinity than HLA-DQ7.5 for gliadin and enhanced binding affinity with a common TCR, agreeing with known results that the HLA-DQ2.5 serotype exhibits increased risk for CeD. Our findings reveal that our proposed absolute binding affinity FEP method is appropriate for predicting HLA binding for disparate antigens with different genotypes. We also discuss atomic-level details of HLA genotypes interacting with gluten peptides and TCRs in regard to the pathogenesis of CeD.
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Affiliation(s)
- Yi Song
- College of Life Sciences, Department of Physics, and Institute of Quantitative Biology, Zhejiang University, Hangzhou 310058, China
| | - Sangyun Lee
- Computational Biology Center, IBM Thomas J Watson Research Center, Yorktown Heights, New York 10598, United States
| | - David Bell
- Computational Biology Center, IBM Thomas J Watson Research Center, Yorktown Heights, New York 10598, United States.,Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, United States
| | - Benjamin Goudey
- School of Computing and Information Systems, The University of Melbourne, Melbourne 3010, Australia
| | - Ruhong Zhou
- College of Life Sciences, Department of Physics, and Institute of Quantitative Biology, Zhejiang University, Hangzhou 310058, China.,Computational Biology Center, IBM Thomas J Watson Research Center, Yorktown Heights, New York 10598, United States.,Department of Chemistry, Columbia University, New York, New York 10027, United States
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6
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Abstract
Thole-style mutual induction models for molecular polarization have been adopted by several popular polarizable force fields (FFs) for their simplicity and transferability. The atomic polarizability parameters of these models are typically derived by fitting to ab initio or/and experimental molecular polarizabilities. In this work, we improve upon Thole polarizability parameters by employing both high-level quantum mechanics molecular polarizabilities and electrostatic potential (ESP) responses on three-dimensional grids. Our results indicate that the two approaches to derive atomic polarizability parameters are both effective, while the ESP approaches can also capture the polarization for the atoms with lone pair electrons. The resulting polarizability parameters have been validated on a set of over 7200 molecules covering the most common elements found in organic molecules (C, H, O, N, P, S, F, Cl, Br, and I). These parameters have also been tested on the experimentally measured molecular polarizabilities of 422 molecules. The final set of parameters derived in this work show notable improvement over the current AMOEBA set. The result is a highly transferable, expanded set of atomic polarizabilities defined by the local chemical environment in the form of SMARTS patterns. These parameters can be used directly in molecular mechanics polarizable potential energy functions such as AMOEBA, AMOEBA+, and other Thole-style models.
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Affiliation(s)
| | | | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
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7
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Klajmon M, Červinka C. Does Explicit Polarizability Improve Simulations of Phase Behavior of Ionic Liquids? J Chem Theory Comput 2021; 17:6225-6239. [PMID: 34520200 DOI: 10.1021/acs.jctc.1c00518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecular dynamics simulations are performed for a test set of 20 aprotic ionic liquids to investigate whether including an explicit polarizability model in the force field leads to higher accuracy and reliability of the calculated phase behavior properties, especially the enthalpy of fusion. A classical nonpolarizable all-atom optimized potentials for liquid simulations (OPLS) force-field model developed by Canongia Lopes and Pádua (CL&P) serves as a reference level of theory. Polarizability is included either in the form of Drude oscillators, resulting in the CL&P-D models, or in the framework of the atomic multipole optimized energetics for biomolecular application (AMOEBA) force field with polarizable atomic sites. Benchmarking of the calculated fusion enthalpy values against the experimental data reveals that overall the nonpolarizable CL&P model and polarizable CL&P-D models perform similarly with average deviations of about 30%. However, fusion enthalpies from the CL&P-D models exhibit a stronger correlation with their experimental counterparts. The least successful predictions are interestingly obtained from AMOEBA (deviation ca. 60%), which may indicate that a reparametrization of this force-field model is needed to achieve improved predictions of the fusion enthalpy. In general, all FF models tend to underestimate the fusion enthalpies. In addition, quantum chemical calculations are used to compute the electronic cohesive energies of the crystalline phases of the ionic liquids and of the interaction energies within the ion pair. Significant positive correlations are found between the fusion enthalpy and the cohesive energies. The character of the present anions predetermines the magnitude of individual mechanistic components of the interaction energy and related enthalpic and cohesive properties.
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Affiliation(s)
- Martin Klajmon
- Department of Physical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Ctirad Červinka
- Department of Physical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
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8
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Walker B, Jing Z, Ren P. Molecular dynamics free energy simulations of ATP:Mg 2+ and ADP:Mg 2+ using the polarizable force field AMOEBA. MOLECULAR SIMULATION 2021; 47:439-448. [PMID: 34421214 DOI: 10.1080/08927022.2020.1725003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
ATPases and GTPases are two important classes of protein that play critical roles in energy transduction, cellular signaling, gene regulation and catalysis. These proteins use cofactors such as nucleoside di and tri-phosphates (NTP, NDP) and can detect the difference between NDP and NTP which then induce different protein conformations. Mechanisms that drive proteins into the NTP or NDP conformation may depend on factors such as ligand structure and how Mg2+ coordinates with the ligand, amino acids in the pocket and water molecules. Here, we have used the advanced electrostatic and polarizable force field AMOEBA and molecular dynamics free energy simulations (MDFE) to examine the various binding mechanisms of ATP:Mg2+ and ADP:Mg2+.We compared the ATP:Mg2+ binding with previous studies using non-polarizable force fields and experimental data on the binding affinity. It was found that the total free energy of binding for ATP:Mg2+ (-7.00 ± 2.13 kcal/mol) is in good agreement with experimental values (-8.6 ± .2 kcal/mol)1. In addition, parameters for relevant protonation states of ATP, ADP, GTP and GDP have been derived. These parameters will allow for researchers to investigate biochemical phenomena involving NTP's and NDP's with greater accuracy than previous studies involving non-polarizable force fields.
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Affiliation(s)
- Brandon Walker
- Department of Biomedical Engineering at The University of Texas at Austin, Austin, Texas 78712, United States
| | - Zhifeng Jing
- Department of Biomedical Engineering at The University of Texas at Austin, Austin, Texas 78712, United States
| | - Pengyu Ren
- Department of Biomedical Engineering at The University of Texas at Austin, Austin, Texas 78712, United States
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9
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Jing Z, Rackers JA, Pratt LR, Liu C, Rempe SB, Ren P. Thermodynamics of ion binding and occupancy in potassium channels. Chem Sci 2021; 12:8920-8930. [PMID: 34257893 PMCID: PMC8246295 DOI: 10.1039/d1sc01887f] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022] Open
Abstract
Potassium channels modulate various cellular functions through efficient and selective conduction of K+ ions. The mechanism of ion conduction in potassium channels has recently emerged as a topic of debate. Crystal structures of potassium channels show four K+ ions bound to adjacent binding sites in the selectivity filter, while chemical intuition and molecular modeling suggest that the direct ion contacts are unstable. Molecular dynamics (MD) simulations have been instrumental in the study of conduction and gating mechanisms of ion channels. Based on MD simulations, two hypotheses have been proposed, in which the four-ion configuration is an artifact due to either averaged structures or low temperature in crystallographic experiments. The two hypotheses have been supported or challenged by different experiments. Here, MD simulations with polarizable force fields validated by ab initio calculations were used to investigate the ion binding thermodynamics. Contrary to previous beliefs, the four-ion configuration was predicted to be thermodynamically stable after accounting for the complex electrostatic interactions and dielectric screening. Polarization plays a critical role in the thermodynamic stabilities. As a result, the ion conduction likely operates through a simple single-vacancy and water-free mechanism. The simulations explained crystal structures, ion binding experiments and recent controversial mutagenesis experiments. This work provides a clear view of the mechanism underlying the efficient ion conduction and demonstrates the importance of polarization in ion channel simulations. Polarization shapes the energy landscape of ion conduction in potassium channels.![]()
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Affiliation(s)
- Zhifeng Jing
- Department of Biomedical Engineering, The University of Texas at Austin Austin Texas 78712 USA
| | - Joshua A Rackers
- Center for Integrated Nanotechnologies, Sandia National Laboratories Albuquerque New Mexico 87185 USA
| | - Lawrence R Pratt
- Department of Chemical and Biomolecular Engineering, Tulane University New Orleans Louisiana 70118 USA
| | - Chengwen Liu
- Department of Biomedical Engineering, The University of Texas at Austin Austin Texas 78712 USA
| | - Susan B Rempe
- Center for Integrated Nanotechnologies, Sandia National Laboratories Albuquerque New Mexico 87185 USA
| | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin Austin Texas 78712 USA
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10
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Çınaroğlu SS, Biggin PC. Evaluating the Performance of Water Models with Host-Guest Force Fields in Binding Enthalpy Calculations for Cucurbit[7]uril-Guest Systems. J Phys Chem B 2021; 125:1558-1567. [PMID: 33538161 DOI: 10.1021/acs.jpcb.0c11383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Computational prediction of thermodynamic components with computational methods has become increasingly routine in computer-aided drug design. Although there has been significant recent effort and improvements in the calculation of free energy, the prediction of enthalpy (and entropy) remains underexplored. Furthermore, there has been relatively little work reported so far that attempts to comparatively assess how well different force fields and water models perform in conjunction with each other. Here, we report a comprehensive assessment of force fields and water models using host-guest systems that mimic many features of protein-ligand systems. These systems are computationally inexpensive, possibly because of their small size compared to protein-ligand systems. We present absolute enthalpy calculations using the multibox approach on a set of 25 cucurbit[7]uril-guest pairs. Eight water models were considered (TIP3P, TIP4P, TIP4P-Ew, SPC, SPC/E, OPC, TIP5P, Bind3P), along with five force fields commonly used in the literature (GAFFv1, GAFFv2, CGenFF, Parsley, and SwissParam). We observe that host-guest binding enthalpies are strongly sensitive to the selection of force field and water model. In terms of water models, we find that TIP3P and its derivative Bind3P are the best performing models for this particular host-guest system. The performance is generally better for aliphatic compounds than for aromatic ones, suggesting that aromaticity remains a difficult property to include accurately in these simple force fields.
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Affiliation(s)
| | - Philip C Biggin
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K
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11
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Heinzelmann G, Gilson MK. Automation of absolute protein-ligand binding free energy calculations for docking refinement and compound evaluation. Sci Rep 2021; 11:1116. [PMID: 33441879 PMCID: PMC7806944 DOI: 10.1038/s41598-020-80769-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 12/24/2020] [Indexed: 02/06/2023] Open
Abstract
Absolute binding free energy calculations with explicit solvent molecular simulations can provide estimates of protein-ligand affinities, and thus reduce the time and costs needed to find new drug candidates. However, these calculations can be complex to implement and perform. Here, we introduce the software BAT.py, a Python tool that invokes the AMBER simulation package to automate the calculation of binding free energies for a protein with a series of ligands. The software supports the attach-pull-release (APR) and double decoupling (DD) binding free energy methods, as well as the simultaneous decoupling-recoupling (SDR) method, a variant of double decoupling that avoids numerical artifacts associated with charged ligands. We report encouraging initial test applications of this software both to re-rank docked poses and to estimate overall binding free energies. We also show that it is practical to carry out these calculations cheaply by using graphical processing units in common machines that can be built for this purpose. The combination of automation and low cost positions this procedure to be applied in a relatively high-throughput mode and thus stands to enable new applications in early-stage drug discovery.
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Affiliation(s)
- Germano Heinzelmann
- Departamento de Física, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil.
| | - Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, USA
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12
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Shi Y, Laury ML, Wang Z, Ponder JW. AMOEBA binding free energies for the SAMPL7 TrimerTrip host-guest challenge. J Comput Aided Mol Des 2021; 35:79-93. [PMID: 33140208 PMCID: PMC7867568 DOI: 10.1007/s10822-020-00358-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/28/2020] [Indexed: 12/22/2022]
Abstract
As part of the SAMPL7 host-guest binding challenge, the AMOEBA force field was applied to calculate the absolute binding free energy for 16 charged organic ammonium guests to the TrimerTrip host, a recently reported acyclic cucurbituril-derived clip host structure with triptycene moieties at its termini. Here we report binding free energy calculations for this system using the AMOEBA polarizable atomic multipole force field and double annihilation free energy methodology. Conformational analysis of the host suggests three families of conformations that do not interconvert in solution on a time scale available to nanosecond molecular dynamics (MD) simulations. Two of these host conformers, referred to as the "indent" and "overlap" structures, are capable of binding guest molecules. As a result, the free energies of all 16 guests binding to both conformations were computed separately, and combined to produce values for comparison with experiment. Initial ranked results submitted as part of the SAMPL7 exercise had a mean unsigned error (MUE) from experimental binding data of 2.14 kcal/mol. Subsequently, a rigorous umbrella sampling reference calculation was used to better determine the free energy difference between unligated "indent" and "overlap" host conformations. Revised binding values for the 16 guests pegged to this umbrella sampling reference reduced the MUE to 1.41 kcal/mol, with a correlation coefficient (Pearson R) between calculated and experimental binding values of 0.832 and a rank correlation (Kendall τ) of 0.65. Overall, the AMOEBA results demonstrate no significant systematic error, suggesting the force field provides an accurate energetic description of the TrimerTrip host, and an appropriate balance of solvation and desolvation effects associated with guest binding.
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Affiliation(s)
- Yuanjun Shi
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Marie L Laury
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Zhi Wang
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Jay W Ponder
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO, 63130, USA.
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63110, USA.
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13
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Schauperl M, Kantonen SM, Wang LP, Gilson MK. Data-driven analysis of the number of Lennard-Jones types needed in a force field. Commun Chem 2020; 3:173. [PMID: 34295996 PMCID: PMC8294475 DOI: 10.1038/s42004-020-00395-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/28/2020] [Indexed: 01/12/2023] Open
Abstract
Force fields used in molecular simulations contain numerical parameters, such as Lennard-Jones (LJ) parameters, which are assigned to the atoms in a molecule based on a classification of their chemical environments. The number of classes, or types, should be no more than needed to maximize agreement with experiment, as parsimony avoids overfitting and simplifies parameter optimization. However, types have historically been crafted based largely on chemical intuition, so current force fields may contain more types than needed. In this study, we seek the minimum number of LJ parameter types needed to represent key properties of organic liquids. We find that highly competitive force field accuracy is obtained with minimalist sets of LJ types; e.g. two H types and one type apiece for C, O, and N atoms. We also find that the fitness surface has multiple minima, which can lead to local trapping of the optimizer.
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Affiliation(s)
- Michael Schauperl
- Skaggs School of Pharmacy and Pharmaceutical Sciences, 9500 Gilman Drive, MC0751, University of California, San Diego, CA 92093-0751 USA
| | - Sophie M Kantonen
- Skaggs School of Pharmacy and Pharmaceutical Sciences, 9500 Gilman Drive, MC0751, University of California, San Diego, CA 92093-0751 USA
| | - Lee-Ping Wang
- Department of Chemistry, University of California, Davis, CA 95616 USA
| | - Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, 9500 Gilman Drive, MC0751, University of California, San Diego, CA 92093-0751 USA
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14
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Kellett K, Slochower DR, Schauperl M, Duggan BM, Gilson MK. Experimental characterization of the association of β-cyclodextrin and eight novel cyclodextrin derivatives with two guest compounds. J Comput Aided Mol Des 2020; 35:95-104. [PMID: 33037548 DOI: 10.1007/s10822-020-00350-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/30/2020] [Indexed: 12/19/2022]
Abstract
We investigate the binding of native β-cyclodextrin (β-CD) and eight novel β-CD derivatives with two different guest compounds, using isothermal calorimetry and 2D NOESY NMR. In all cases, the stoichiometry is 1:1 and binding is exothermic. Overall, modifications at the 3' position of β-CD, which is at the secondary face, weaken binding by several kJ/mol relative to native β-CD, while modifications at the 6' position (primary face) maintain or somewhat reduce the binding affinity. The variations in binding enthalpy are larger than the variations in binding free energy, so entropy-enthalpy compensation is observed. Characterization of the bound conformations with NOESY NMR shows that the polar groups of the guests may be situated at either face, depending on the host molecule, and, in some cases, both orientations are populated. The present results were used in the SAMPL7 blinded prediction challenge whose results are detailed in the same special issue of JCAMD.
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Affiliation(s)
- K Kellett
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0751, USA
| | - D R Slochower
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0751, USA
| | - M Schauperl
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0751, USA
| | - B M Duggan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0751, USA
| | - M K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0751, USA.
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15
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Ding Y, Xu Y, Qian C, Chen J, Zhu J, Huang H, Shi Y, Huang J. Predicting partition coefficients of drug-like molecules in the SAMPL6 challenge with Drude polarizable force fields. J Comput Aided Mol Des 2020; 34:421-435. [PMID: 31960252 DOI: 10.1007/s10822-020-00282-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 01/08/2020] [Indexed: 12/14/2022]
Abstract
The water-octanol partition coefficient is an important physicochemical property for small molecule drug design. Here, we report our participation in the SAMPL6 logP prediction challenge with free energy perturbation (FEP) calculations in the water phase and in the 1-octanol phase using Drude polarizable force fields. Root mean square error (RMSE) and mean absolute error (MAE) of our prediction are equal to 1.85 and 1.25 logP units. The errors are not evenly distributed. Out of eleven SAMPL6 solutes, FEP/Drude performed very badly on three molecules (deviations all larger than 2 logP units) but good on the remaining eight (deviations all less than 1 logP unit). We find while FEP converges well within one nanosecond in water, simulations in 1-octanol need much longer simulation time and possibly more independent runs for sampling. We also find out that 1-octanol, albeit being a non-polar solvent, still polarizes solute molecules and forms stable hydrogen bonds with them. At the end, we attempt to reweight FEP trajectories with QM/Drude calculations and discuss possible caveats in our simulation setup.
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Affiliation(s)
- Ye Ding
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - You Xu
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Cheng Qian
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Jinfeng Chen
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Jian Zhu
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Houhou Huang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Yi Shi
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Jing Huang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China. .,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.
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16
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El Khoury L, El Hage K, Piquemal JP, Fermandjian S, Maroun RG, Gresh N, Hobaika Z. Spectrometric and computational studies of the binding of HIV-1 integrase inhibitors to viral DNA extremities. PEERJ PHYSICAL CHEMISTRY 2019. [DOI: 10.7717/peerj-pchem.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Three integrase strand transfer inhibitors are in intensive clinical use, raltegravir (RAL), elvitegravir (EVG) and dolutegravir (DTG). The onset of integrase resistance mutations limits their therapeutic efficiency. As put forth earlier, the drug affinity for the intasome could be improved by targeting preferentially the retroviral nucleobases, which are little, if at all, mutation-prone. We report experimental results of anisotropy fluorescence titrations of viral DNA by these three drugs. These show the DTG > EVG > RAL ranking of their inhibitory activities of the intasome to correspond to that of their free energies of binding, ∆Gs, to retroviral DNA, and that such a ranking is only governed by the binding enthalpies, ∆H, the entropy undergoing marginal variations. We sought whether this ranking might be reproduced through quantum chemistry (QC) Density Functional Theory calculations of intermolecular interaction energies between simplified models consisting of sole halobenzene ring and the highly conserved retroviral nucleobases G4 and C16. These calculations showed that binding of EVG has a small preference over DTG, while RAL ranked third. This indicates that additional interactions of the diketoacid parts of the drugs with DNA could be necessary to further enable preferential binding of DTG. The corresponding ∆Etotvalues computed with a polarizable molecular mechanics/dynamics procedure, Sum of Interactions Between Fragments Ab initio computed (SIBFA), showed good correlations with this ∆E(QC) ranking. These validations are an important step toward the use of polarizable molecular dynamics simulations on DTG or EVG derivatives in their complexes with the complete intasome, an application now motivated and enabled by the advent of currently developed and improved massively parallel software.
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Affiliation(s)
- Léa El Khoury
- Laboratoire de Chimie Théorique, UMR7616 CNRS, Sorbonne Université, Paris, France
- UR EGP, Centre d’Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
- Present address: Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, USA
| | - Krystel El Hage
- Chemistry and Biology Nucleo(s)tides and Immunology for Therapy (CBNIT), UMR 8601 CNRS, UFR Biomedicale, Paris, France
- Present address: Laboratoire Structure-Activité des Biomolécules Normales et Pathologiques, INSERM U829, Université Evry-Val d’Essonne, Evry, France
| | - Jean-Philip Piquemal
- UR EGP, Centre d’Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
- Institut Universitaire de France, Paris, France
| | - Serge Fermandjian
- Chemistry and Biology Nucleo(s)tides and Immunology for Therapy (CBNIT), UMR 8601 CNRS, UFR Biomedicale, Paris, France
| | - Richard G. Maroun
- UR EGP, Centre d’Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
| | - Nohad Gresh
- Laboratoire de Chimie Théorique, UMR7616 CNRS, Sorbonne Université, Paris, France
| | - Zeina Hobaika
- UR EGP, Centre d’Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
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17
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Jing Z, Qi R, Thibonnier M, Ren P. Molecular Dynamics Study of the Hybridization between RNA and Modified Oligonucleotides. J Chem Theory Comput 2019; 15:6422-6432. [PMID: 31553600 PMCID: PMC6889957 DOI: 10.1021/acs.jctc.9b00519] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
MicroRNAs (miRNAs) are attractive drug candidates for many diseases as they can modulate the expression of gene networks. Recently, we discovered that DNAs targeting microRNA-22-3p (miR-22-3p) hold the potential for treating obesity and related metabolic disorders (type 2 diabetes mellitus, hyperlipidemia, and nonalcoholic fatty liver disease (NAFLD)) by turning fat-storing white adipocytes into fat-burning adipocytes. In this work, we explored the effects of chemical modifications, including phosphorothioate (PS), locked nucleic acid (LNA), and peptide nucleic acid (PNA), on the structure and energy of DNA analogs by using molecular dynamics (MD) simulations. To achieve a reliable prediction of the hybridization free energy, the AMOEBA polarizable force field and the free energy perturbation technique were employed. The calculated hybridization free energies are generally compatible with previous experiments. For LNA and PNA, the enhanced duplex stability can be explained by the preorganization mechanism, i.e., the single strands adopt stable helical structures similar to those in the duplex. For PS, the S and R isomers (Sp and Rp) have preferences for C2'-endo and C3'-endo sugar puckering conformations, respectively, and therefore Sp is less stable than Rp in DNA/RNA hybrids. In addition, the solvation penalty of Rp accounts for its destabilization effect. PS-LNA is similar to LNA as the sugar puckering is dominated by the locked sugar ring. This work demonstrated that MD simulations with polarizable force fields are useful for the understanding and design of modified nucleic acids.
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Affiliation(s)
- Zhifeng Jing
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712
| | - Rui Qi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712
| | | | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712
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18
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Leonhard AC, Whitmer JK. Accurate Determination of Cavitand Binding Free Energies via Unrestrained Advanced Sampling. J Chem Theory Comput 2019; 15:5761-5768. [DOI: 10.1021/acs.jctc.9b00348] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Anne C. Leonhard
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jonathan K. Whitmer
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
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19
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Qi R, Walker B, Jing Z, Yu M, Stancu G, Edupuganti R, Dalby KN, Ren P. Computational and Experimental Studies of Inhibitor Design for Aldolase A. J Phys Chem B 2019; 123:6034-6041. [PMID: 31268712 DOI: 10.1021/acs.jpcb.9b04551] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Glycolytic enzyme fructose-bisphosphate aldolase A is an emerging therapeutic target in cancer. Recently, we have solved the crystal structure of murine aldolase in complex with naphthalene-2,6-diyl bisphosphate (ND1) that served as a template of the design of bisphosphate-based inhibitors. In this work, a series of ND1 analogues containing difluoromethylene (-CF2), methylene (-CH2), or aldehyde substitutions were designed. All designed compounds were studied using molecular dynamics (MD) simulations with the AMOEBA force field. Both energetics and structural analyses have been done to understand the calculated binding free energies. The average distances between ligand and protein atoms for ND1 were very similar to those for the ND1 crystal structure, which indicates that our MD simulation is sampling the correct conformation well. CF2 insertion lowers the binding free energy by 10-15 kcal/mol, while CF2 substitution slightly increases the binding free energy, which matches the experimental measurement. In addition, we found that NDB with two CF2 insertions, the strongest binder, is entropically driven, while others including NDA with one CF2 insertion are all enthalpically driven. This work provides insights into the mechanisms underlying protein-phosphate binding and enhances the capability of applying computational and theoretical frameworks to model, predict, and design diagnostic strategies targeting cancer.
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Affiliation(s)
| | | | | | - Maiya Yu
- Department of Biochemistry and Mathematics , University of Michigan , Ann Arbor , Michigan 48109 , United States
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20
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Liu C, Piquemal JP, Ren P. AMOEBA+ Classical Potential for Modeling Molecular Interactions. J Chem Theory Comput 2019; 15:4122-4139. [PMID: 31136175 DOI: 10.1021/acs.jctc.9b00261] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Classical potentials based on isotropic and additive atomic charges have been widely used to model molecules in computers for the past few decades. The crude approximations in the underlying physics are hindering both their accuracy and transferability across chemical and physical environments. Here we present a new classical potential, AMOEBA+, to capture essential intermolecular forces, including permanent electrostatics, repulsion, dispersion, many-body polarization, short-range charge penetration, and charge transfer, by extending the polarizable multipole-based AMOEBA (Atomic Multipole Optimized Energetics for Biomolecular Applications) model. For a set of common organic molecules, we show that AMOEBA+ with general parameters can reproduce both quantum mechanical interactions and energy decompositions according to Symmetry-Adapted Perturbation Theory (SAPT). Additionally, a new water model based on the AMOEBA+ framework captures various liquid-phase properties in molecular dynamics simulations while remaining consistent with SAPT energy decompositions, utilizing both ab initio data and experimental liquid properties. Our results demonstrate that it is possible to improve the physical basis of classical force fields to advance their accuracy and general applicability.
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Affiliation(s)
- Chengwen Liu
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Jean-Philip Piquemal
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States.,Laboratoire de Chimie Théorique , Sorbonne Université, UMR7616 CNRS , Paris 75252 , France.,Institut Universitaire de France , Paris Cedex 05, 75005 , France
| | - Pengyu Ren
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
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21
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Harger M, Lee JH, Walker B, Taliaferro JM, Edupuganti R, Dalby KN, Ren P. Computational insights into the binding of IN17 inhibitors to MELK. J Mol Model 2019; 25:151. [PMID: 31069524 PMCID: PMC7105934 DOI: 10.1007/s00894-019-4036-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 04/15/2019] [Indexed: 12/19/2022]
Abstract
The protein kinase MELK is an important kinase in cell signaling and has shown to be a promising anti-cancer target. Recent work has resulted in a novel small molecule scaffold targeting MELK, IN17. However, there has been little structural information or physical understanding of MELK-IN17 interactions. Using Tinker-OpenMM on GPUs, we have performed free energy simulations on MELK binding with IN17 and 11 derivatives. This series of studies provides structural insights into how substitution on IN17 leads to differences in complex structure and binding thermodynamics. In addition, this study serves as an assessment of the current capabilities of the AMOEBA forcefield, accelerated by GPU computing, to serve as a molecular-dynamics-based free energy simulation platform for lead optimization.
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Affiliation(s)
- Matthew Harger
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Ju-Hyeon Lee
- Division of Chemical Biology and Medicinal Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Brandon Walker
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Juliana M Taliaferro
- Division of Chemical Biology and Medicinal Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Ramakrishna Edupuganti
- Division of Chemical Biology and Medicinal Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA.
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22
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Jing Z, Liu C, Cheng SY, Qi R, Walker BD, Piquemal JP, Ren P. Polarizable Force Fields for Biomolecular Simulations: Recent Advances and Applications. Annu Rev Biophys 2019; 48:371-394. [PMID: 30916997 DOI: 10.1146/annurev-biophys-070317-033349] [Citation(s) in RCA: 217] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Realistic modeling of biomolecular systems requires an accurate treatment of electrostatics, including electronic polarization. Due to recent advances in physical models, simulation algorithms, and computing hardware, biomolecular simulations with advanced force fields at biologically relevant timescales are becoming increasingly promising. These advancements have not only led to new biophysical insights but also afforded opportunities to advance our understanding of fundamental intermolecular forces. This article describes the recent advances and applications, as well as future directions, of polarizable force fields in biomolecular simulations.
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Affiliation(s)
- Zhifeng Jing
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Chengwen Liu
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Sara Y Cheng
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Rui Qi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Brandon D Walker
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Jean-Philip Piquemal
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA; .,Sorbonne Université, CNRS, Laboratoire de Chimie Theórique, 75252 Paris CEDEX 05, France.,Institut Universitaire de France, 75005 Paris, France
| | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
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23
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Hagler AT. Force field development phase II: Relaxation of physics-based criteria… or inclusion of more rigorous physics into the representation of molecular energetics. J Comput Aided Mol Des 2018; 33:205-264. [DOI: 10.1007/s10822-018-0134-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/18/2018] [Indexed: 01/04/2023]
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24
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Laury ML, Wang Z, Gordon AS, Ponder JW. Absolute binding free energies for the SAMPL6 cucurbit[8]uril host-guest challenge via the AMOEBA polarizable force field. J Comput Aided Mol Des 2018; 32:1087-1095. [PMID: 30324303 DOI: 10.1007/s10822-018-0147-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 08/09/2018] [Indexed: 01/17/2023]
Abstract
As part of the SAMPL6 host-guest blind challenge, the AMOEBA force field was applied to calculate the absolute binding free energy for a cucurbit[8]uril host complexed with 14 diverse guests, ranging from small, rigid structures to drug molecules. The AMOEBA results from the initial submission prompted an investigation into aspects of the methodology and parameterization employed. Lessons learned from the blind challenge include: a double annihilation scheme (electrostatics and van der Waals) is needed to obtain proper sampling of guest conformations, annihilation of key torsion parameters of the guest are recommended for flexible guests, and a more thorough analysis of torsion parameters is warranted. When put in to practice with the AMOEBA model, the lessons learned improved the MUE from 2.63 to 1.20 kcal/mol and the RMSE from 3.62 to 1.68 kcal/mol, respectively. Overall, the AMOEBA protocol for determining absolute binding free energies benefitted from participation in the SAMPL6 host-guest blind challenge and the results suggest the implementation of the methodology in future host-guest calculations.
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Affiliation(s)
- Marie L Laury
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Zhi Wang
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Aaron S Gordon
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Jay W Ponder
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO, 63130, USA.
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25
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Rackers JA, Wang Z, Lu C, Laury ML, Lagardère L, Schnieders MJ, Piquemal JP, Ren P, Ponder JW. Tinker 8: Software Tools for Molecular Design. J Chem Theory Comput 2018; 14:5273-5289. [PMID: 30176213 PMCID: PMC6335969 DOI: 10.1021/acs.jctc.8b00529] [Citation(s) in RCA: 290] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Tinker software, currently released as version 8, is a modular molecular mechanics and dynamics package written primarily in a standard, easily portable dialect of Fortran 95 with OpenMP extensions. It supports a wide variety of force fields, including polarizable models such as the Atomic Multipole Optimized Energetics for Biomolecular Applications (AMOEBA) force field. The package runs on Linux, macOS, and Windows systems. In addition to canonical Tinker, there are branches, Tinker-HP and Tinker-OpenMM, designed for use on message passing interface (MPI) parallel distributed memory supercomputers and state-of-the-art graphical processing units (GPUs), respectively. The Tinker suite also includes a tightly integrated Java-based graphical user interface called Force Field Explorer (FFE), which provides molecular visualization capabilities as well as the ability to launch and control Tinker calculations.
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Affiliation(s)
- Joshua A. Rackers
- Program in Computational & Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Zhi Wang
- Department of Chemistry, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
| | - Chao Lu
- Department of Chemistry, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
| | - Marie L. Laury
- Department of Chemistry, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
| | - Louis Lagardère
- Laboratoire de Chimie Théorique, Sorbonne Universités, UPMC Paris 06, UMR 7616, case courrier 137, 4 place Jussieu, F-75005, Paris, France
| | - Michael J. Schnieders
- Department of Biomedical Engineering, The University of Iowa, Iowa City, IA 52242, United States
| | - Jean-Philip Piquemal
- Laboratoire de Chimie Théorique, Sorbonne Universités, UPMC Paris 06, UMR 7616, case courrier 137, 4 place Jussieu, F-75005, Paris, France
| | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jay W. Ponder
- Program in Computational & Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
- Department of Chemistry, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
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26
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Rizzi A, Murkli S, McNeill JN, Yao W, Sullivan M, Gilson MK, Chiu MW, Isaacs L, Gibb BC, Mobley DL, Chodera JD. Overview of the SAMPL6 host-guest binding affinity prediction challenge. J Comput Aided Mol Des 2018; 32:937-963. [PMID: 30415285 PMCID: PMC6301044 DOI: 10.1007/s10822-018-0170-6] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/07/2018] [Indexed: 10/27/2022]
Abstract
Accurately predicting the binding affinities of small organic molecules to biological macromolecules can greatly accelerate drug discovery by reducing the number of compounds that must be synthesized to realize desired potency and selectivity goals. Unfortunately, the process of assessing the accuracy of current computational approaches to affinity prediction against binding data to biological macromolecules is frustrated by several challenges, such as slow conformational dynamics, multiple titratable groups, and the lack of high-quality blinded datasets. Over the last several SAMPL blind challenge exercises, host-guest systems have emerged as a practical and effective way to circumvent these challenges in assessing the predictive performance of current-generation quantitative modeling tools, while still providing systems capable of possessing tight binding affinities. Here, we present an overview of the SAMPL6 host-guest binding affinity prediction challenge, which featured three supramolecular hosts: octa-acid (OA), the closely related tetra-endo-methyl-octa-acid (TEMOA), and cucurbit[8]uril (CB8), along with 21 small organic guest molecules. A total of 119 entries were received from ten participating groups employing a variety of methods that spanned from electronic structure and movable type calculations in implicit solvent to alchemical and potential of mean force strategies using empirical force fields with explicit solvent models. While empirical models tended to obtain better performance than first-principle methods, it was not possible to identify a single approach that consistently provided superior results across all host-guest systems and statistical metrics. Moreover, the accuracy of the methodologies generally displayed a substantial dependence on the system considered, emphasizing the need for host diversity in blind evaluations. Several entries exploited previous experimental measurements of similar host-guest systems in an effort to improve their physical-based predictions via some manner of rudimentary machine learning; while this strategy succeeded in reducing systematic errors, it did not correspond to an improvement in statistical correlation. Comparison to previous rounds of the host-guest binding free energy challenge highlights an overall improvement in the correlation obtained by the affinity predictions for OA and TEMOA systems, but a surprising lack of improvement regarding root mean square error over the past several challenge rounds. The data suggests that further refinement of force field parameters, as well as improved treatment of chemical effects (e.g., buffer salt conditions, protonation states), may be required to further enhance predictive accuracy.
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Affiliation(s)
- Andrea Rizzi
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Tri-Institutional Training Program in Computational Biology and Medicine, New York, NY, 10065, USA
| | - Steven Murkli
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA
| | - John N McNeill
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA
| | - Wei Yao
- Department of Chemistry, Tulane University, Louisiana, LA, 70118, USA
| | - Matthew Sullivan
- Department of Chemistry, Tulane University, Louisiana, LA, 70118, USA
| | - Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Michael W Chiu
- Qualcomm Institute, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Lyle Isaacs
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA
| | - Bruce C Gibb
- Department of Chemistry, Tulane University, Louisiana, LA, 70118, USA
| | - David L Mobley
- Department of Pharmaceutical Sciences and Department of Chemistry, University of California, Irvine, California, 92697, USA.
| | - John D Chodera
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
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27
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Rackers JA, Liu C, Ren P, Ponder JW. A physically grounded damped dispersion model with particle mesh Ewald summation. J Chem Phys 2018; 149:084115. [PMID: 30193468 DOI: 10.1063/1.5030434] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Accurate modeling of dispersion is critical to the goal of predictive biomolecular simulations. To achieve this accuracy, a model must be able to correctly capture both the short-range and asymptotic behavior of dispersion interactions. We present here a damped dispersion model based on the overlap of charge densities that correctly captures both regimes. The overlap damped dispersion model represents a classical physical interpretation of dispersion: the interaction between the instantaneous induced dipoles of two distinct charge distributions. This model is shown to be an excellent fit with symmetry adapted perturbation theory dispersion energy calculations, yielding an RMS error on the S101x7 database of 0.5 kcal/mol. Moreover, the damping function used in this model is wholly derived and parameterized from the electrostatic dipole-dipole interaction, making it not only physically grounded but transferable as well.
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Affiliation(s)
- Joshua A Rackers
- Program in Computational and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri 63110, USA
| | - Chengwen Liu
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Jay W Ponder
- Program in Computational and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri 63110, USA
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28
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Yin J, Henriksen NM, Muddana HS, Gilson MK. Bind3P: Optimization of a Water Model Based on Host-Guest Binding Data. J Chem Theory Comput 2018; 14:3621-3632. [PMID: 29874074 DOI: 10.1021/acs.jctc.8b00318] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a water model, Bind3P (Version 0.1), which was obtained by using sensitivity analysis to readjust the Lennard-Jones parameters of the TIP3P model against experimental binding free energies for six host-guest systems, along with pure liquid properties. Tests of Bind3P against >100 experimental binding free energies and enthalpies for host-guest systems distinct from the training set show a consistent drop in the mean signed error, relative to matched calculations with TIP3P. Importantly, Bind3P also yields some improvement in the hydration free energies of small organic molecules and preserves the accuracy of bulk water properties, such as density and the heat of vaporization. The same approach can be applied to more sophisticated water models that can better represent pure water properties. These results lend further support to the concept of integrating host-guest binding data into force field parametrization.
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Affiliation(s)
- Jian Yin
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
| | - Niel M Henriksen
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
| | - Hari S Muddana
- OpenEye Scientific Software , 9 Bisbee Court , Santa Fe , New Mexico 87508 , United States
| | - Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
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29
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Jing Z, Qi R, Liu C, Ren P. Study of interactions between metal ions and protein model compounds by energy decomposition analyses and the AMOEBA force field. J Chem Phys 2018; 147:161733. [PMID: 29096462 DOI: 10.1063/1.4985921] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The interactions between metal ions and proteins are ubiquitous in biology. The selective binding of metal ions has a variety of regulatory functions. Therefore, there is a need to understand the mechanism of protein-ion binding. The interactions involving metal ions are complicated in nature, where short-range charge-penetration, charge transfer, polarization, and many-body effects all contribute significantly, and a quantitative description of all these interactions is lacking. In addition, it is unclear how well current polarizable force fields can capture these energy terms and whether these polarization models are good enough to describe the many-body effects. In this work, two energy decomposition methods, absolutely localized molecular orbitals and symmetry-adapted perturbation theory, were utilized to study the interactions between Mg2+/Ca2+ and model compounds for amino acids. Comparison of individual interaction components revealed that while there are significant charge-penetration and charge-transfer effects in Ca complexes, these effects can be captured by the van der Waals (vdW) term in the AMOEBA force field. The electrostatic interaction in Mg complexes is well described by AMOEBA since the charge penetration is small, but the distance-dependent polarization energy is problematic. Many-body effects were shown to be important for protein-ion binding. In the absence of many-body effects, highly charged binding pockets will be over-stabilized, and the pockets will always favor Mg and thus lose selectivity. Therefore, many-body effects must be incorporated in the force field in order to predict the structure and energetics of metalloproteins. Also, the many-body effects of charge transfer in Ca complexes were found to be non-negligible. The absorption of charge-transfer energy into the additive vdW term was a main source of error for the AMOEBA many-body interaction energies.
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Affiliation(s)
- Zhifeng Jing
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Rui Qi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Chengwen Liu
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
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30
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Qiu Y, Schwegler BR, Wang LP. Polarizable Molecular Simulations Reveal How Silicon-Containing Functional Groups Govern the Desalination Mechanism in Nanoporous Graphene. J Chem Theory Comput 2018; 14:4279-4290. [DOI: 10.1021/acs.jctc.8b00226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Yudong Qiu
- Chemistry Department, The University of California, Davis, Davis, California 95616, United States
| | - Benedict R. Schwegler
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Lee-Ping Wang
- Chemistry Department, The University of California, Davis, Davis, California 95616, United States
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31
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Toward Expanded Diversity of Host–Guest Interactions via Synthesis and Characterization of Cyclodextrin Derivatives. J SOLUTION CHEM 2018. [DOI: 10.1007/s10953-018-0769-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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32
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Zhang C, Lu C, Jing Z, Wu C, Piquemal JP, Ponder JW, Ren P. AMOEBA Polarizable Atomic Multipole Force Field for Nucleic Acids. J Chem Theory Comput 2018; 14:2084-2108. [PMID: 29438622 PMCID: PMC5893433 DOI: 10.1021/acs.jctc.7b01169] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The AMOEBA polarizable atomic multipole force field for nucleic acids is presented. Valence and electrostatic parameters were determined from high-level quantum mechanical data, including structures, conformational energy, and electrostatic potentials, of nucleotide model compounds. Previously derived parameters for the phosphate group and nucleobases were incorporated. A total of over 35 μs of condensed-phase molecular dynamics simulations of DNA and RNA molecules in aqueous solution and crystal lattice were performed to validate and refine the force field. The solution and/or crystal structures of DNA B-form duplexes, RNA duplexes, and hairpins were captured with an average root-mean-squared deviation from NMR structures below or around 2.0 Å. Structural details, such as base pairing and stacking, sugar puckering, backbone and χ-torsion angles, groove geometries, and crystal packing interfaces, agreed well with NMR and/or X-ray. The interconversion between A- and B-form DNAs was observed in ethanol-water mixtures at 328 K. Crystal lattices of B- and Z-form DNA and A-form RNA were examined with simulations. For the RNA tetraloop, single strand tetramers, and HIV TAR with 29 residues, the simulated conformational states, 3 J-coupling, nuclear Overhauser effect, and residual dipolar coupling data were compared with NMR results. Starting from a totally unstacked/unfolding state, the rCAAU tetranucleotide was folded into A-form-like structures during ∼1 μs molecular dynamics simulations.
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Affiliation(s)
- Changsheng Zhang
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Chao Lu
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, United States
| | - Zhifeng Jing
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Chuanjie Wu
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, United States
| | - Jean-Philip Piquemal
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
- Laboratoire de Chimie Théorique, Sorbonne Universités, UPMC, UMR7616 CNRS, Paris, France
| | - Jay W. Ponder
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, United States
| | - Pengyu Ren
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
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33
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Kilburg D, Gallicchio E. Assessment of a Single Decoupling Alchemical Approach for the Calculation of the Absolute Binding Free Energies of Protein-Peptide Complexes. Front Mol Biosci 2018; 5:22. [PMID: 29568737 PMCID: PMC5852065 DOI: 10.3389/fmolb.2018.00022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/21/2018] [Indexed: 01/24/2023] Open
Abstract
The computational modeling of peptide inhibitors to target protein-protein binding interfaces is growing in interest as these are often too large, too shallow, and too feature-less for conventional small molecule compounds. Here, we present a rare successful application of an alchemical binding free energy method for the calculation of converged absolute binding free energies of a series of protein-peptide complexes. Specifically, we report the binding free energies of a series of cyclic peptides derived from the LEDGF/p75 protein to the integrase receptor of the HIV1 virus. The simulations recapitulate the effect of mutations relative to the wild-type binding motif of LEDGF/p75, providing structural, energetic and dynamical interpretations of the observed trends. The equilibration and convergence of the calculations are carefully analyzed. Convergence is aided by the adoption of a single-decoupling alchemical approach with implicit solvation, which circumvents the convergence difficulties of conventional double-decoupling protocols. We hereby present the single-decoupling methodology and critically evaluate its advantages and limitations. We also discuss some of the challenges and potential pitfalls of binding free energy calculations for complex molecular systems which have generally limited their applicability to the quantitative study of protein-peptide binding equilibria.
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Affiliation(s)
- Denise Kilburg
- Department of Chemistry, Brooklyn College, Brooklyn, NY, United States.,Ph.D. Program in Chemistry, The Graduate Center, City University of New York, New York, NY, United States
| | - Emilio Gallicchio
- Department of Chemistry, Brooklyn College, Brooklyn, NY, United States.,Ph.D. Program in Chemistry, The Graduate Center, City University of New York, New York, NY, United States.,Ph.D. Program in Biochemistry, The Graduate Center, City University of New York, New York, NY, United States
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34
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Wang C, Ren P, Luo R. Ionic Solution: What Goes Right and Wrong with Continuum Solvation Modeling. J Phys Chem B 2017; 121:11169-11179. [PMID: 29164898 DOI: 10.1021/acs.jpcb.7b09616] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Solvent-mediated electrostatic interactions were well recognized to be important in the structure and function of molecular systems. Ionic interaction is an important component in electrostatic interactions, especially in highly charged molecules, such as nucleic acids. Here, we focus on the quality of the widely used Poisson-Boltzmann surface area (PBSA) continuum models in modeling ionic interactions by comparing with both explicit solvent simulations and the experiment. In this work, the molality-dependent chemical potentials for sodium chloride (NaCl) electrolyte were first simulated in the SPC/E explicit solvent. Our high-quality simulation agrees well with both the previous study and the experiment. Given the free-energy simulations in SPC/E as the benchmark, we used the same sets of snapshots collected in the SPC/E solvent model for PBSA free-energy calculations in the hope to achieve the maximum consistency between the two solvent models. Our comparative analysis shows that the molality-dependent chemical potentials of NaCl were reproduced well with both linear PB and nonlinear PB methods, although nonlinear PB agrees better with SPC/E and the experiment. Our free-energy simulations also show that the presence of salt increases the hydrophobic effect in a nonlinear fashion, in qualitative agreement with previous theoretical studies of Onsager and Samaras. However, the lack of molality-dependency in the nonelectrostatics continuum models dramatically reduces the overall quality of PBSA methods in modeling salt-dependent energetics. These analyses point to further improvements needed for more robust modeling of solvent-mediated interactions by the continuum solvation frameworks.
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Affiliation(s)
| | - Pengyu Ren
- Department of Biomedical Engineering, University of Texas , Austin, Texas 78712, United States
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35
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Harger M, Li D, Wang Z, Dalby K, Lagardère L, Piquemal JP, Ponder J, Ren P. Tinker-OpenMM: Absolute and relative alchemical free energies using AMOEBA on GPUs. J Comput Chem 2017; 38:2047-2055. [PMID: 28600826 DOI: 10.1002/jcc.24853] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 05/06/2017] [Indexed: 12/27/2022]
Abstract
The capabilities of the polarizable force fields for alchemical free energy calculations have been limited by the high computational cost and complexity of the underlying potential energy functions. In this work, we present a GPU-based general alchemical free energy simulation platform for polarizable potential AMOEBA. Tinker-OpenMM, the OpenMM implementation of the AMOEBA simulation engine has been modified to enable both absolute and relative alchemical simulations on GPUs, which leads to a ∼200-fold improvement in simulation speed over a single CPU core. We show that free energy values calculated using this platform agree with the results of Tinker simulations for the hydration of organic compounds and binding of host-guest systems within the statistical errors. In addition to absolute binding, we designed a relative alchemical approach for computing relative binding affinities of ligands to the same host, where a special path was applied to avoid numerical instability due to polarization between the different ligands that bind to the same site. This scheme is general and does not require ligands to have similar scaffolds. We show that relative hydration and binding free energy calculated using this approach match those computed from the absolute free energy approach. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Matthew Harger
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712
| | - Daniel Li
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712
| | - Zhi Wang
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, 63130
| | - Kevin Dalby
- Division of Chemical Biology and Medicinal Chemistry, University of Texas at Austin, Austin, Texas, 78712
| | - Louis Lagardère
- Institut des Sciences du Calcul et des Données, UPMC Université Paris 06, F-75005, Paris, France
| | - Jean-Philip Piquemal
- Laboratoire de Chimie Théorique, Sorbonne Universités, UPMC, UMR7616 CNRS, Paris, France.,Institut Universitaire de France, Paris Cedex 05, 75231, France
| | - Jay Ponder
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, 63130
| | - Pengyu Ren
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712
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36
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Ruiz Pestana L, Mardirossian N, Head-Gordon M, Head-Gordon T. Ab initio molecular dynamics simulations of liquid water using high quality meta-GGA functionals. Chem Sci 2017; 8:3554-3565. [PMID: 30155200 PMCID: PMC6092720 DOI: 10.1039/c6sc04711d] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 02/24/2017] [Indexed: 01/23/2023] Open
Abstract
We have used ab initio molecular dynamics (AIMD) to characterize water properties using two meta-generalized gradient approximation (meta-GGA) functionals, M06-L-D3 and B97M-rV, and compared their performance against a standard GGA corrected for dispersion, revPBE-D3, at ambient conditions (298 K, and 1 g cm-3 or 1 atm). Simulations of the equilibrium density, radial distribution functions, self-diffusivity, the infrared spectrum, liquid dipole moments, and characterizations of the hydrogen bond network show that all three functionals have overcome the problem of the early AIMD simulations that erroneously found ambient water to be highly structured, but they differ substantially among themselves in agreement with experiment on this range of water properties. We show directly using water cluster data up through the pentamer that revPBE-D3 benefits from a cancellation of its intrinsic functional error by running classical trajectories, whereas the meta-GGA functionals are demonstrably more accurate and would require the simulation of nuclear quantum effects to realize better agreement with all cluster and condensed phase properties.
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Affiliation(s)
- Luis Ruiz Pestana
- Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , USA .
| | - Narbe Mardirossian
- Kenneth S. Pitzer Center for Theoretical Chemistry , Department of Chemistry , University of California , Berkeley , USA
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry , Department of Chemistry , University of California , Berkeley , USA
| | - Teresa Head-Gordon
- Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , USA .
- Kenneth S. Pitzer Center for Theoretical Chemistry , Department of Chemistry , University of California , Berkeley , USA
- Departments of Chemistry , Bioengineering , Chemical and Biomolecular Engineering , University of California , Berkeley , USA
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37
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Albaugh A, Bradshaw RT, Demerdash O, Dziedzic J, Mao Y, Margul DT, Swails J, Boateng HA, Case DA, Eastman P, Essex JW, Head-Gordon M, Pande VS, Ponder J, Shao Y, Skylaris C, Todorov IT, Tuckerman ME, Zeng Q, Head-Gordon T. Advanced Potential Energy Surfaces for Molecular Simulation. J Phys Chem B 2016; 120:9811-32. [PMID: 27513316 PMCID: PMC9113031 DOI: 10.1021/acs.jpcb.6b06414] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Advanced potential energy surfaces are defined as theoretical models that explicitly include many-body effects that transcend the standard fixed-charge, pairwise-additive paradigm typically used in molecular simulation. However, several factors relating to their software implementation have precluded their widespread use in condensed-phase simulations: the computational cost of the theoretical models, a paucity of approximate models and algorithmic improvements that can ameliorate their cost, underdeveloped interfaces and limited dissemination in computational code bases that are widely used in the computational chemistry community, and software implementations that have not kept pace with modern high-performance computing (HPC) architectures, such as multicore CPUs and modern graphics processing units (GPUs). In this Feature Article we review recent progress made in these areas, including well-defined polarization approximations and new multipole electrostatic formulations, novel methods for solving the mutual polarization equations and increasing the MD time step, combining linear-scaling electronic structure methods with new QM/MM methods that account for mutual polarization between the two regions, and the greatly improved software deployment of these models and methods onto GPU and CPU hardware platforms. We have now approached an era where multipole-based polarizable force fields can be routinely used to obtain computational results comparable to state-of-the-art density functional theory while reaching sampling statistics that are acceptable when compared to that obtained from simpler fixed partial charge force fields.
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Affiliation(s)
- Alex Albaugh
- Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720
| | - Richard T. Bradshaw
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Omar Demerdash
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Jacek Dziedzic
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
- Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Poland
| | - Yuezhi Mao
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Daniel T. Margul
- Department of Chemistry, New York University, New York, NY 10003, USA
| | - Jason Swails
- Department of Chemistry and Chemical Biology and BioMaPS Institute, Rutgers University, Piscataway, New Jersey 08854-8066, United States
| | - Henry A. Boateng
- Department of Mathematics, Bates College, 2 Andrews Road, Lewiston, ME 04240
| | - David A. Case
- Department of Chemistry and Chemical Biology and BioMaPS Institute, Rutgers University, Piscataway, New Jersey 08854-8066, United States
| | - Peter Eastman
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Jonathan W. Essex
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | | | - Vijay S. Pande
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Jay Ponder
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, 63130
| | - Yihan Shao
- Q-Chem Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588
| | - Chris Skylaris
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Illian T. Todorov
- STFC Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD, UK
| | - Mark E. Tuckerman
- Department of Chemistry, New York University, New York, NY 10003, USA
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10003, USA
- NYU-ECNU, Center for Computational Chemistry at NYU, Shanghai, Shanghai 200062, China
| | - Qiao Zeng
- Laboratory of Computational Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Teresa Head-Gordon
- Department of Chemistry, University of California, Berkeley, CA 94720
- Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720
- Bioengineering, University of California, Berkeley, CA 94720
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