1
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Bairagya HR, Tasneem A, Sarmadhikari D. Structural and thermodynamic properties of conserved water molecules in Mpro native: A combined approach by MD simulation and Grid Inhomogeneous Solvation Theory. Proteins 2024; 92:735-749. [PMID: 38213131 DOI: 10.1002/prot.26665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 12/28/2023] [Accepted: 01/01/2024] [Indexed: 01/13/2024]
Abstract
The new viral strains of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are continuously rising, becoming more virulent, and transmissible. Therefore, the development of new antiviral drugs is essential. Due to its significant role in the viral life cycle of SARS-CoV-2, the main protease (Mpro) enzyme is a leading target for antiviral drug design. The Mpro monomer consists of domain DI, DII, and DI-DII interface. Twenty-one conserved water molecules (W4-W24) are occupied at these domains according to multiple crystal structure analyses. The crystal and MD structures reveal the presence of eight conserved water sites in domain DI, DII and remaining in the DI-DII interface. Grid-based inhomogeneous fluid solvation theory (GIST) was employed on MD structures of Mpro native to predict structural and thermodynamic properties of each conserved water site for focusing to identify the specific conserved water molecules that can easily be displaced by proposed ligands. Finally, MD water W13 is emerged as a promising candidate for water mimic drug design due to its low mean interaction energy, loose binding character with the protein, and its involvement in a water-mediated H-bond with catalytic His41 via the interaction Thr25(OG)---W13---W---His41(NE2). In this context, water occupancy, relative interaction energy, entropy, and topologies of W13 are thermodynamically acceptable for the water displacement method. Therefore, the strategic use of W13's geometrical position in the DI domain may be implemented for drug discovery against COVID disease by designing new ligands with appropriately oriented chemical groups to mimic its structural, electronic, and thermodynamic properties.
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Affiliation(s)
- Hridoy R Bairagya
- Computational Drug Design and Bio-molecular Simulation Lab, Department of Bioinformatics, Maulana Abul Kalam Azad University of Technology, Haringhata, West Bengal, India
| | - Alvea Tasneem
- Mathematical and Computational Biology Laboratory, Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Debapriyo Sarmadhikari
- Computational Drug Design and Bio-molecular Simulation Lab, Department of Bioinformatics, Maulana Abul Kalam Azad University of Technology, Haringhata, West Bengal, India
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2
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Gilson MK, Kurtzman T. Free Energy Density of a Fluid and Its Role in Solvation and Binding. J Chem Theory Comput 2024; 20:2871-2887. [PMID: 38536144 PMCID: PMC11197885 DOI: 10.1021/acs.jctc.3c01173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
The concept that a fluid has a position-dependent free energy density appears in the literature but has not been fully developed or accepted. We set this concept on an unambiguous theoretical footing via the following strategy. First, we set forth four desiderata that should be satisfied by any definition of the position-dependent free energy density, f(R), in a system comprising only a fluid and a rigid solute: its volume integral, plus the fixed internal energy of the solute, should be the system free energy; it deviates from its bulk value, fbulk, near a solute but should asymptotically approach fbulk with increasing distance from the solute; it should go to zero where the solvent density goes to zero; and it should be well-defined in the most general case of a fluid made up of flexible molecules with an arbitrary interaction potential. Second, we use statistical thermodynamics to formulate a definition of the free energy density that satisfies these desiderata. Third, we show how any free energy density satisfying the desiderata may be used to analyze molecular processes in solution. In particular, because the spatial integral of f(R) equals the free energy of the system, it can be used to compute free energy changes that result from the rearrangement of solutes as well as the forces exerted on the solutes by the solvent. This enables the use of a thermodynamic analysis of water in protein binding sites to inform ligand design. Finally, we discuss related literature and address published concerns regarding the thermodynamic plausibility of a position-dependent free energy density. The theory presented here has applications in theoretical and computational chemistry and may be further generalizable beyond fluids, such as to solids and macromolecules.
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Affiliation(s)
- Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, and Department of Chemistry and Biochemistry, UC San Diego, La Jolla, CA, 92093, USA
| | - Tom Kurtzman
- PhD Programs in Chemistry, Biochemistry, and Biology, The Graduate Center of the City University of New York, New York, 10016, USA; Department of Chemistry, Lehman College, The City University of New York, Bronx, New York, 10468, USA
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3
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Wu T, King MR, Farag M, Pappu RV, Lew MD. Single fluorogen imaging reveals distinct environmental and structural features of biomolecular condensates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.26.525727. [PMID: 36747818 PMCID: PMC9900924 DOI: 10.1101/2023.01.26.525727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Recent computations suggest that biomolecular condensates that form via macromolecular phase separation are network fluids featuring spatially inhomogeneous organization of the underlying molecules. Computations also point to unique conformations of molecules at condensate interfaces. Here, we test these predictions using high-resolution structural characterizations of condensates formed by intrinsically disordered prion-like low complexity domains (PLCDs). We leveraged the localization and orientational preferences of freely diffusing fluorogens and the solvatochromic effect whereby specific fluorogens are turned on in response to the physic-chemical properties of condensate microenvironments to facilitate single-molecule tracking and super-resolution imaging. We deployed three different fluorogens to probe internal microenvironments and molecular organization of PLCD condensates. The spatiotemporal resolution and environmental sensitivity afforded by single-fluorogen imaging shows that the internal environments of condensates are more hydrophobic than coexisting dilute phases. Molecules within condensates are organized in a spatially inhomogeneous manner featuring slow-moving nanoscale molecular clusters or hubs that coexist with fast-moving molecules. Finally, molecules at interfaces of condensates are found to have distinct orientational preferences when compared to the interiors. Our findings, which affirm computational predictions, help provide a structural basis for condensate viscoelasticity and dispel the notion of protein condensates being isotropic liquids defined by uniform internal densities.
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Affiliation(s)
- Tingting Wu
- Department of Electrical and Systems Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
| | - Matthew R King
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Department of Biomedical Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
| | - Mina Farag
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Department of Biomedical Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
| | - Rohit V Pappu
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Department of Biomedical Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
| | - Matthew D Lew
- Department of Electrical and Systems Engineering, Washington University in St. Louis, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis; St. Louis, MO 63130, USA
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4
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Abstract
Multivalent proteins and nucleic acids, collectively referred to as multivalent associative biomacromolecules, provide the driving forces for the formation and compositional regulation of biomolecular condensates. Here, we review the key concepts of phase transitions of aqueous solutions of associative biomacromolecules, specifically proteins that include folded domains and intrinsically disordered regions. The phase transitions of these systems come under the rubric of coupled associative and segregative transitions. The concepts underlying these processes are presented, and their relevance to biomolecular condensates is discussed.
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Affiliation(s)
- Rohit V Pappu
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Samuel R Cohen
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Center of Regenerative Medicine, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Furqan Dar
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Mina Farag
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Mrityunjoy Kar
- Max Planck Institute of Cell Biology and Genetics, 01307 Dresden, Germany
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5
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Eberhardt J, Forli S. WaterKit: Thermodynamic Profiling of Protein Hydration Sites. J Chem Theory Comput 2023; 19:2535-2556. [PMID: 37094087 PMCID: PMC10732097 DOI: 10.1021/acs.jctc.2c01087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
Water desolvation is one of the key components of the free energy of binding of small molecules to their receptors. Thus, understanding the energetic balance of solvation and desolvation resulting from individual water molecules can be crucial when estimating ligand binding, especially when evaluating different molecules and poses as done in High-Throughput Virtual Screening (HTVS). Over the most recent decades, several methods were developed to tackle this problem, ranging from fast approximate methods (usually empirical functions using either discrete atom-atom pairwise interactions or continuum solvent models) to more computationally expensive and accurate ones, mostly based on Molecular Dynamics (MD) simulations, such as Grid Inhomogeneous Solvation Theory (GIST) or Double Decoupling. On one hand, MD-based methods are prohibitive to use in HTVS to estimate the role of waters on the fly for each ligand. On the other hand, fast and approximate methods show an unsatisfactory level of accuracy, with low agreement with results obtained with the more expensive methods. Here we introduce WaterKit, a new grid-based sampling method with explicit water molecules to calculate thermodynamic properties using the GIST method. Our results show that the discrete placement of water molecules is successful in reproducing the position of crystallographic waters with very high accuracy, as well as providing thermodynamic estimates with accuracy comparable to more expensive MD simulations. Unlike these methods, WaterKit can be used to analyze specific regions on the protein surface, (such as the binding site of a receptor), without having to hydrate and simulate the whole receptor structure. The results show the feasibility of a general and fast method to compute thermodynamic properties of water molecules, making it well-suited to be integrated in high-throughput pipelines such as molecular docking.
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Affiliation(s)
- Jerome Eberhardt
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, California 92037, United States
| | - Stefano Forli
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, California 92037, United States
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6
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Rocha REO, Mariano DCB, Almeida TS, CorrêaCosta LS, Fischer PHC, Santos LH, Caffarena ER, da Silveira CH, Lamp LM, Fernandez-Quintero ML, Liedl KR, de Melo-Minardi RC, de Lima LHF. Thermostabilizing mechanisms of canonical single amino acid substitutions at a GH1 β-glucosidase probed by multiple MD and computational approaches. Proteins 2023; 91:218-236. [PMID: 36114781 DOI: 10.1002/prot.26424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 09/01/2022] [Accepted: 09/06/2022] [Indexed: 01/07/2023]
Abstract
β-glucosidases play a pivotal role in second-generation biofuel (2G-biofuel) production. For this application, thermostable enzymes are essential due to the denaturing conditions on the bioreactors. Random amino acid substitutions have originated new thermostable β-glucosidases, but without a clear understanding of their molecular mechanisms. Here, we probe by different molecular dynamics simulation approaches with distinct force fields and submitting the results to various computational analyses, the molecular bases of the thermostabilization of the Paenibacillus polymyxa GH1 β-glucosidase by two-point mutations E96K (TR1) and M416I (TR2). Equilibrium molecular dynamic simulations (eMD) at different temperatures, principal component analysis (PCA), virtual docking, metadynamics (MetaDy), accelerated molecular dynamics (aMD), Poisson-Boltzmann surface analysis, grid inhomogeneous solvation theory and colony method estimation of conformational entropy allow to converge to the idea that the stabilization carried by both substitutions depend on different contributions of three classic mechanisms: (i) electrostatic surface stabilization; (ii) efficient isolation of the hydrophobic core from the solvent, with energetic advantages at the solvation cap; (iii) higher distribution of the protein dynamics at the mobile active site loops than at the protein core, with functional and entropic advantages. Mechanisms i and ii predominate for TR1, while in TR2, mechanism iii is dominant. Loop A integrity and loops A, C, D, and E dynamics play critical roles in such mechanisms. Comparison of the dynamic and topological changes observed between the thermostable mutants and the wildtype protein with amino acid co-evolutive networks and thermostabilizing hotspots from the literature allow inferring that the mechanisms here recovered can be related to the thermostability obtained by different substitutions along the whole family GH1. We hope the results and insights discussed here can be helpful for future rational approaches to the engineering of optimized β-glucosidases for 2G-biofuel production for industry, biotechnology, and science.
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Affiliation(s)
- Rafael Eduardo Oliveira Rocha
- Laboratory of Molecular Modelling and Bioinformatics (LAMMB), Department of Physical and Biological Sciences, Campus Sete Lagoas, Universidade Federal de São João Del Rei, Sete Lagoas, Brazil.,Laboratory of Bioinformatics and Systems (LBS), Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Laboratory of Molecular Modeling and Drug Design, Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Diego César Batista Mariano
- Laboratory of Bioinformatics and Systems (LBS), Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Tiago Silva Almeida
- Laboratory of Molecular Modelling and Bioinformatics (LAMMB), Department of Physical and Biological Sciences, Campus Sete Lagoas, Universidade Federal de São João Del Rei, Sete Lagoas, Brazil
| | - Leon Sulfierry CorrêaCosta
- Laboratory of Molecular Modelling and Bioinformatics (LAMMB), Department of Physical and Biological Sciences, Campus Sete Lagoas, Universidade Federal de São João Del Rei, Sete Lagoas, Brazil.,Computational Modeling Coordination (COMOD), Laboratório Nacional de Computação Científica (LNCC), Petrópolis, Brazil
| | - Pedro Henrique Camargo Fischer
- Laboratory of Molecular Modelling and Bioinformatics (LAMMB), Department of Physical and Biological Sciences, Campus Sete Lagoas, Universidade Federal de São João Del Rei, Sete Lagoas, Brazil
| | - Lucianna Helene Santos
- Laboratory of Bioinformatics and Systems (LBS), Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Laboratory of Molecular Modeling and Drug Design, Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | - Leonida M Lamp
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Chemistry and Biomedicine Innsbruck (CCB), University of Innsbruck, Innsbruck, Austria
| | - Monica Lisa Fernandez-Quintero
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Chemistry and Biomedicine Innsbruck (CCB), University of Innsbruck, Innsbruck, Austria
| | - Klaus Roman Liedl
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Chemistry and Biomedicine Innsbruck (CCB), University of Innsbruck, Innsbruck, Austria
| | - Raquel Cardoso de Melo-Minardi
- Laboratory of Bioinformatics and Systems (LBS), Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Leonardo Henrique França de Lima
- Laboratory of Molecular Modelling and Bioinformatics (LAMMB), Department of Physical and Biological Sciences, Campus Sete Lagoas, Universidade Federal de São João Del Rei, Sete Lagoas, Brazil.,Institute of General, Inorganic and Theoretical Chemistry, and Center for Chemistry and Biomedicine Innsbruck (CCB), University of Innsbruck, Innsbruck, Austria
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7
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Prediction of local thermodynamics of water in and around endo-functionalized molecular tube receptors: An approach using grid inhomogeneous solvation theory. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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8
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Vasilakaki S, Kraml J, Schauperl M, Liedl KR, Kokotos G. Hydration thermodynamics of cytosolic phospholipase A 2 GIVA predict its membrane-associated parts and its highly hydrated binding site. J Biomol Struct Dyn 2020; 39:953-959. [PMID: 32085688 DOI: 10.1080/07391102.2020.1733665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
During biological events, the water molecules associated with the protein are re-oriented to adapt to the new conditions, inducing changes in the system's free energy. The characterization of water structure and thermodynamics may facilitate the prediction of certain biological events, such as the binding of a ligand and the membrane-associated parts of a protein. In this computational study, we calculated the hydration thermodynamics of cytosolic phospholipase A2 group IV (GIVA cPLA2) to study the hydration properties of the protein's surface and binding pocket. Hydrophobicity scales and the Grid Inhomogeneous Solvation Theory (GIST) tool were employed for the calculations. The hydrophobic areas of the protein's surface were predicted more accurately with the GIST method rather than with the hydrophobicity scales. Based on this, a model of the protein-membrane complex was constructed. In addition, the calculation revealed the highly hydrated binding pocket that further contribute to our understanding of the ligands' binding. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sofia Vasilakaki
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Johannes Kraml
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Tyrol, Austria
| | - Michael Schauperl
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Tyrol, Austria
| | - Klaus R Liedl
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Tyrol, Austria
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
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9
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He P, Sarkar S, Gallicchio E, Kurtzman T, Wickstrom L. Role of Displacing Confined Solvent in the Conformational Equilibrium of β-Cyclodextrin. J Phys Chem B 2019; 123:8378-8386. [PMID: 31509409 DOI: 10.1021/acs.jpcb.9b07028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study investigates the role of hydration and its relationship to the conformational equilibrium of the host molecule β-cyclodextrin. Molecular dynamics simulations indicate that the unbound β-cyclodextrin exhibits two state behavior in explicit solvent due to the opening and closing of its cavity. In implicit solvent, these transitions are not observed, and there is one dominant conformation of β-cyclodextrin with an open cavity. Based on these observations, we investigate the hypothesis that the expulsion of thermodynamically unfavorable water molecules into the bulk plays an important role in controlling the accessibility of the closed macrostate at room temperature. We compare the results of the molecular mechanics analytical generalized Born plus nonpolar solvation approach to those obtained through grid inhomogeneous solvation theory analysis with explicit solvation to elucidate the thermodynamic forces at play. The work illustrates the use of continuum solvent models to tease out solvation effects related to the inhomogeneity and the molecular nature of water and demonstrates the key role of the thermodynamics of enclosed hydration in driving the conformational equilibrium of molecules in solution.
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Affiliation(s)
- Peng He
- Center for Biophysics & Computational Biology/ICMS, Department of Chemistry , Temple University , Philadelphia , Pennsylvania 19122 , United States
| | - Sheila Sarkar
- Department of Science , Borough of Manhattan Community College, The City University of New York , New York , New York 10007 , United States
| | - Emilio Gallicchio
- Department of Chemistry , Brooklyn College, The City University of New York , Brooklyn , New York 11210 , United States.,Ph.D. Programs in Chemistry & Biochemistry , The Graduate Center of the City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
| | - Tom Kurtzman
- Department of Chemistry , Lehman College, The City University of New York , Bronx , New York 10468 , United States.,Ph.D. Programs in Chemistry & Biochemistry , The Graduate Center of the City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
| | - Lauren Wickstrom
- Department of Science , Borough of Manhattan Community College, The City University of New York , New York , New York 10007 , United States
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10
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Pal RK, Gadhiya S, Ramsey S, Cordone P, Wickstrom L, Harding WW, Kurtzman T, Gallicchio E. Inclusion of enclosed hydration effects in the binding free energy estimation of dopamine D3 receptor complexes. PLoS One 2019; 14:e0222902. [PMID: 31568493 PMCID: PMC6768453 DOI: 10.1371/journal.pone.0222902] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/30/2019] [Indexed: 01/04/2023] Open
Abstract
Confined hydration and conformational flexibility are some of the challenges encountered for the rational design of selective antagonists of G-protein coupled receptors. We present a set of C3-substituted (-)-stepholidine derivatives as potent binders of the dopamine D3 receptor. The compounds are characterized biochemically, as well as by computer modeling using a novel molecular dynamics-based alchemical binding free energy approach which incorporates the effect of the displacement of enclosed water molecules from the binding site. The free energy of displacement of specific hydration sites is obtained using the Hydration Site Analysis method with explicit solvation. This work underscores the critical role of confined hydration and conformational reorganization in the molecular recognition mechanism of dopamine receptors and illustrates the potential of binding free energy models to represent these key phenomena.
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Affiliation(s)
- Rajat Kumar Pal
- Department of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, NY 11210, United States of America
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
| | - Satishkumar Gadhiya
- PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- Department of Chemistry, Hunter College, 695 Park Avenue, NY 10065, United States of America
| | - Steven Ramsey
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- Department of Chemistry, Lehman College, 250 Bedford Park Blvd. West, Bronx, NY 10468, United States of America
| | - Pierpaolo Cordone
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- Department of Chemistry, Hunter College, 695 Park Avenue, NY 10065, United States of America
| | - Lauren Wickstrom
- Department of Science, Borough of Manhattan Community College, 199 Chambers Street, New York, NY 10007, United States of America
| | - Wayne W. Harding
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- Department of Chemistry, Hunter College, 695 Park Avenue, NY 10065, United States of America
| | - Tom Kurtzman
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- Department of Chemistry, Lehman College, 250 Bedford Park Blvd. West, Bronx, NY 10468, United States of America
| | - Emilio Gallicchio
- Department of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, NY 11210, United States of America
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States of America
- * E-mail:
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11
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Balance between hydration enthalpy and entropy is important for ice binding surfaces in Antifreeze Proteins. Sci Rep 2017; 7:11901. [PMID: 28928396 PMCID: PMC5605524 DOI: 10.1038/s41598-017-11982-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 08/29/2017] [Indexed: 11/21/2022] Open
Abstract
Antifreeze Proteins (AFPs) inhibit the growth of an ice crystal by binding to it. The detailed binding mechanism is, however, still not fully understood. We investigated three AFPs using Molecular Dynamics simulations in combination with Grid Inhomogeneous Solvation Theory, exploring their hydration thermodynamics. The observed enthalpic and entropic differences between the ice-binding sites and the inactive surface reveal key properties essential for proteins in order to bind ice: While entropic contributions are similar for all sites, the enthalpic gain for all ice-binding sites is lower than for the rest of the protein surface. In contrast to most of the recently published studies, our analyses show that enthalpic interactions are as important as an ice-like pre-ordering. Based on these observations, we propose a new, thermodynamically more refined mechanism of the ice recognition process showing that the appropriate balance between entropy and enthalpy facilitates ice-binding of proteins. Especially, high enthalpic interactions between the protein surface and water can hinder the ice-binding activity.
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12
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Molavi Tabrizi A, Goossens S, Mehdizadeh Rahimi A, Cooper CD, Knepley MG, Bardhan JP. Extending the Solvation-Layer Interface Condition Continum Electrostatic Model to a Linearized Poisson–Boltzmann Solvent. J Chem Theory Comput 2017; 13:2897-2914. [DOI: 10.1021/acs.jctc.6b00832] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amirhossein Molavi Tabrizi
- Department
of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - Spencer Goossens
- Department
of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - Ali Mehdizadeh Rahimi
- Department
of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - Christopher D. Cooper
- Departamento
de Ingeniería Mecánica and Centro Científico
Tecnológico de Valparaíso (CCTVal), Universidad Técnica Federico Santa María, Valparaiso, Chile
| | - Matthew G. Knepley
- Department
of Computational and Applied Mathematics, Rice University, Houston, Texas 77005, United States
| | - Jaydeep P. Bardhan
- Department
of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, United States
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13
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Levy RM, Cui D, Zhang BW, Matubayasi N. Relationship between Solvation Thermodynamics from IST and DFT Perspectives. J Phys Chem B 2017; 121:3825-3841. [PMID: 28186751 DOI: 10.1021/acs.jpcb.6b12889] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Inhomogeneous solvation theory (IST) and classical density functional theory (DFT) each provide a framework for relating distribution functions of solutions to their thermodynamic properties. As reviewed in this work, both IST and DFT can be formulated in a way that use two "end point" simulations, one of the pure solvent and the other of the solution, to determine the solute chemical potential and other thermodynamic properties of the solution and of subvolumes in regions local to the solute containing hydrating waters. In contrast to IST, where expressions for the excess energy and entropy of solution are the object of analysis, in the DFT end point formulation of the problem, the solute-solvent potential of mean force (PMF) plays a central role. The indirect part of the PMF corresponds to the lowest order (1-body) truncation of the IST expression. Because the PMF is a free energy function, powerful numerical methods can be used to estimate it. We show that the DFT expressions for the solute excess chemical potential can be written in a form which is local, involving integrals only over regions proximate to the solute. The DFT end point route to estimating solvation free energies provides an alternative path to that of IST for analyzing solvation effects on molecular recognition and conformational changes in solution, which can lead to new insights. In order to illustrate the kind of information that is contained in the solute-solvent PMF, we have carried out simulations of β-cyclodextrin in water. This solute is a well studied "host" molecule to which "guest" molecules bind; host-guest systems serve as models for molecular recognition. We illustrate the range of values the direct and indirect parts of the solute-solvent PMF can have as a water molecule is brought to the interface of β-cyclodextrin from the bulk; we discuss the "competition" between these two terms, and the role it plays in molecular recognition.
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Affiliation(s)
- Ronald M Levy
- Center for Biophysics and Computational Biology, Department of Chemistry, and Institute for Computational Molecular Science, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Di Cui
- Center for Biophysics and Computational Biology, Department of Chemistry, and Institute for Computational Molecular Science, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Bin W Zhang
- Center for Biophysics and Computational Biology, Department of Chemistry, and Institute for Computational Molecular Science, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Nobuyuki Matubayasi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan and Elements Strategy Initiative for Catalysts and Batteries, Kyoto University , Katsura, Kyoto 615-8520, Japan
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14
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Grabowska J, Kuffel A, Zielkiewicz J. Structure of solvation water around the active and inactive regions of a type III antifreeze protein and its mutants of lowered activity. J Chem Phys 2017; 145:075101. [PMID: 27544127 DOI: 10.1063/1.4961094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Water molecules from the solvation shell of the ice-binding surface are considered important for the antifreeze proteins to perform their function properly. Herein, we discuss the problem whether the extent of changes of the mean properties of solvation water can be connected with the antifreeze activity of the protein. To this aim, the structure of solvation water of a type III antifreeze protein from Macrozoarces americanus (eel pout) is investigated. A wild type of the protein is used, along with its three mutants, with antifreeze activities equal to 54% or 10% of the activity of the native form. The solvation water of the ice-binding surface and the rest of the protein are analyzed separately. To characterize the structure of solvation shell, parameters describing radial and angular characteristics of the mutual arrangement of the molecules were employed. They take into account short-distance (first hydration shell) or long-distance (two solvation shells) effects. The obtained results and the comparison with the results obtained previously for a hyperactive antifreeze protein from Choristoneura fumiferana lead to the conclusion that the structure and amino acid composition of the active region of the protein evolved to achieve two goals. The first one is the modification of the properties of the solvation water. The second one is the geometrical adjustment of the protein surface to the specific crystallographic plane of ice. Both of these goals have to be achieved simultaneously in order for the protein to perform its function properly. However, they seem to be independent from one another in a sense that very small antifreeze activity does not imply that properties of water become different from the ones observed for the wild type. The proteins with significantly lower activity still modify the mean properties of solvation water in a right direction, in spite of the fact that the accuracy of the geometrical match with the ice lattice is lost because of the mutations. Therefore, we do not observe any correlation between the antifreeze activity and the extent of modification of the properties of solvation water.
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Affiliation(s)
- Joanna Grabowska
- Faculty of Chemistry, Department of Physical Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland
| | - Anna Kuffel
- Faculty of Chemistry, Department of Physical Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland
| | - Jan Zielkiewicz
- Faculty of Chemistry, Department of Physical Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland
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15
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Pal RK, Haider K, Kaur D, Flynn W, Xia J, Levy RM, Taran T, Wickstrom L, Kurtzman T, Gallicchio E. A combined treatment of hydration and dynamical effects for the modeling of host-guest binding thermodynamics: the SAMPL5 blinded challenge. J Comput Aided Mol Des 2017; 31:29-44. [PMID: 27696239 PMCID: PMC5477994 DOI: 10.1007/s10822-016-9956-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/25/2016] [Indexed: 01/02/2023]
Abstract
As part of the SAMPL5 blinded experiment, we computed the absolute binding free energies of 22 host-guest complexes employing a novel approach based on the BEDAM single-decoupling alchemical free energy protocol with parallel replica exchange conformational sampling and the AGBNP2 implicit solvation model specifically customized to treat the effect of water displacement as modeled by the Hydration Site Analysis method with explicit solvation. Initial predictions were affected by the lack of treatment of ionic charge screening, which is very significant for these highly charged hosts, and resulted in poor relative ranking of negatively versus positively charged guests. Binding free energies obtained with Debye-Hückel treatment of salt effects were in good agreement with experimental measurements. Water displacement effects contributed favorably and very significantly to the observed binding affinities; without it, the modeling predictions would have grossly underestimated binding. The work validates the implicit/explicit solvation approach employed here and it shows that comprehensive physical models can be effective at predicting binding affinities of molecular complexes requiring accurate treatment of conformational dynamics and hydration.
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Affiliation(s)
- Rajat Kumar Pal
- Department of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, New York, 11210, USA
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Kamran Haider
- Department of Chemistry, Lehman College, The City University of New York, 250 Bedford Park Blvd. West, Bronx, New York, NY, 10468, USA
| | - Divya Kaur
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - William Flynn
- Center for Biophysics and Computational Biology, Institute of Computational Molecular Science and Department of Chemistry, Temple University, Philadelphia, PA, USA
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, 08854, USA
| | - Junchao Xia
- Center for Biophysics and Computational Biology, Institute of Computational Molecular Science and Department of Chemistry, Temple University, Philadelphia, PA, USA
| | - Ronald M Levy
- Center for Biophysics and Computational Biology, Institute of Computational Molecular Science and Department of Chemistry, Temple University, Philadelphia, PA, USA
| | - Tetiana Taran
- Borough of Manhattan Community College, Department of Science, The City University of New York, 199 Chambers Street, New York, NY, 10007, USA
| | - Lauren Wickstrom
- Borough of Manhattan Community College, Department of Science, The City University of New York, 199 Chambers Street, New York, NY, 10007, USA
| | - Tom Kurtzman
- Department of Chemistry, Lehman College, The City University of New York, 250 Bedford Park Blvd. West, Bronx, New York, NY, 10468, USA
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Emilio Gallicchio
- Department of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, New York, 11210, USA.
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA.
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA.
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16
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Huggins DJ. Studying the role of cooperative hydration in stabilizing folded protein states. J Struct Biol 2016; 196:394-406. [PMID: 27633532 PMCID: PMC5131609 DOI: 10.1016/j.jsb.2016.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/03/2016] [Accepted: 09/07/2016] [Indexed: 01/19/2023]
Abstract
Understanding and modelling protein folding remains a key scientific and engineering challenge. Two key questions in protein folding are (1) why many proteins adopt a folded state and (2) how these proteins transition from the random coil ensemble to a folded state. In this paper we employ molecular dynamics simulations to address the first of these questions. Computational methods are well-placed to address this issue due to their ability to analyze systems at atomic-level resolution. Traditionally, the stability of folded proteins has been ascribed to the balance of two types of intermolecular interactions: hydrogen-bonding interactions and hydrophobic contacts. In this study, we explore a third type of intermolecular interaction: cooperative hydration of protein surface residues. To achieve this, we consider multiple independent simulations of the villin headpiece domain to quantify the contributions of different interactions to the energy of the native and fully extended states. In addition, we consider whether these findings are robust with respect to the protein forcefield, the water model, and the presence of salt. In all cases, we identify many cooperatively hydrated interactions that are transient but energetically favor the native state. Whilst further work on additional protein structures, forcefields, and water models is necessary, these results suggest a role for cooperative hydration in protein folding that should be explored further. Rational design of cooperative hydration on the protein surface could be a viable strategy for increasing protein stability.
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Affiliation(s)
- David J Huggins
- Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, 19 J J Thomson Avenue, Cambridge CB3 0HE, United Kingdom; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom.
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17
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Vukovic S, Brennan PE, Huggins DJ. Exploring the role of water in molecular recognition: predicting protein ligandability using a combinatorial search of surface hydration sites. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:344007. [PMID: 27367338 DOI: 10.1088/0953-8984/28/34/344007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The interaction between any two biological molecules must compete with their interaction with water molecules. This makes water the most important molecule in medicine, as it controls the interactions of every therapeutic with its target. A small molecule binding to a protein is able to recognize a unique binding site on a protein by displacing bound water molecules from specific hydration sites. Quantifying the interactions of these water molecules allows us to estimate the potential of the protein to bind a small molecule. This is referred to as ligandability. In the study, we describe a method to predict ligandability by performing a search of all possible combinations of hydration sites on protein surfaces. We predict ligandability as the summed binding free energy for each of the constituent hydration sites, computed using inhomogeneous fluid solvation theory. We compared the predicted ligandability with the maximum observed binding affinity for 20 proteins in the human bromodomain family. Based on this comparison, it was determined that effective inhibitors have been developed for the majority of bromodomains, in the range from 10 to 100 nM. However, we predict that more potent inhibitors can be developed for the bromodomains BPTF and BRD7 with relative ease, but that further efforts to develop inhibitors for ATAD2 will be extremely challenging. We have also made predictions for the 14 bromodomains with no reported small molecule K d values by isothermal titration calorimetry. The calculations predict that PBRM1(1) will be a challenging target, while others such as TAF1L(2), PBRM1(4) and TAF1(2), should be highly ligandable. As an outcome of this work, we assembled a database of experimental maximal K d that can serve as a community resource assisting medicinal chemistry efforts focused on BRDs. Effective prediction of ligandability would be a very useful tool in the drug discovery process.
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Affiliation(s)
- Sinisa Vukovic
- Department of Physics, Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge, CB3 0HE, UK
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18
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Dickson CJ, Hornak V, Velez-Vega C, McKay DJJ, Reilly J, Sandham DA, Shaw D, Fairhurst RA, Charlton SJ, Sykes DA, Pearlstein RA, Duca JS. Uncoupling the Structure-Activity Relationships of β2 Adrenergic Receptor Ligands from Membrane Binding. J Med Chem 2016; 59:5780-9. [PMID: 27239696 DOI: 10.1021/acs.jmedchem.6b00358] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Ligand binding to membrane proteins may be significantly influenced by the interaction of ligands with the membrane. In particular, the microscopic ligand concentration within the membrane surface solvation layer may exceed that in bulk solvent, resulting in overestimation of the intrinsic protein-ligand binding contribution to the apparent/measured affinity. Using published binding data for a set of small molecules with the β2 adrenergic receptor, we demonstrate that deconvolution of membrane and protein binding contributions allows for improved structure-activity relationship analysis and structure-based drug design. Molecular dynamics simulations of ligand bound membrane protein complexes were used to validate binding poses, allowing analysis of key interactions and binding site solvation to develop structure-activity relationships of β2 ligand binding. The resulting relationships are consistent with intrinsic binding affinity (corrected for membrane interaction). The successful structure-based design of ligands targeting membrane proteins may require an assessment of membrane affinity to uncouple protein binding from membrane interactions.
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Affiliation(s)
- Callum J Dickson
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Viktor Hornak
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Camilo Velez-Vega
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Daniel J J McKay
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - John Reilly
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - David A Sandham
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Duncan Shaw
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Robin A Fairhurst
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Novartis Pharma AG , Werk Klybeck, Postfach, CH-4002 Basel, Switzerland
| | - Steven J Charlton
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Queen's Medical Centre , Nottingham NG7 2UH, U.K
| | - David A Sykes
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Queen's Medical Centre , Nottingham NG7 2UH, U.K
| | - Robert A Pearlstein
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Jose S Duca
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
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19
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Haider K, Wickstrom L, Ramsey S, Gilson MK, Kurtzman T. Enthalpic Breakdown of Water Structure on Protein Active-Site Surfaces. J Phys Chem B 2016; 120:8743-56. [PMID: 27169482 DOI: 10.1021/acs.jpcb.6b01094] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The principles underlying water reorganization around simple nonpolar solutes are well understood and provide the framework for the classical hydrophobic effect, whereby water molecules structure themselves around solutes so that they maintain favorable energetic contacts with both the solute and the other water molecules. However, for certain solute surface topographies, water molecules, due to their geometry and size, are unable to simultaneously maintain favorable energetic contacts with both the surface and neighboring water molecules. In this study, we analyze the solvation of ligand-binding sites for six structurally diverse proteins using hydration site analysis and measures of local water structure, in order to identify surfaces at which water molecules are unable to structure themselves in a way that maintains favorable enthalpy relative to bulk water. These surfaces are characterized by a high degree of enclosure, weak solute-water interactions, and surface constraints that induce unfavorable pair interactions between neighboring water molecules. Additionally, we find that the solvation of charged side chains in an active site generally results in favorable enthalpy but can also lead to pair interactions between neighboring water molecules that are significantly unfavorable relative to bulk water. We find that frustrated local structure can occur not only in apolar and weakly polar pockets, where overall enthalpy tends to be unfavorable, but also in charged pockets, where overall water enthalpy tends to be favorable. The characterization of local water structure in these terms may prove useful for evaluating the displacement of water from diverse protein active-site environments.
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Affiliation(s)
- Kamran Haider
- Department of Chemistry, Lehman College, The City University of New York , 250 Bedford Park Boulevard West, Bronx, New York 10468, United States
| | - Lauren Wickstrom
- Borough of Manhattan Community College, Department of Science, The City University of New York , 199 Chambers Street, New York, New York 10007, United States
| | - Steven Ramsey
- Department of Chemistry, Lehman College, The City University of New York , 250 Bedford Park Boulevard West, Bronx, New York 10468, United States.,Ph.D. Program in Biochemistry, The Graduate Center of The City University of New York , 365 Fifth Avenue, New York, New York 10016, United States
| | - Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego , 9500 Gilman Drive, La Jolla, California 92093-0736, United States
| | - Tom Kurtzman
- Department of Chemistry, Lehman College, The City University of New York , 250 Bedford Park Boulevard West, Bronx, New York 10468, United States.,Ph.D. Program in Biochemistry, The Graduate Center of The City University of New York , 365 Fifth Avenue, New York, New York 10016, United States.,Ph.D. Program in Chemistry, The Graduate Center of The City University of New York , 365 Fifth Avenue, New York, New York 10016, United States
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20
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Kührová P, Otyepka M, Šponer J, Banáš P. Are Waters around RNA More than Just a Solvent? - An Insight from Molecular Dynamics Simulations. J Chem Theory Comput 2015; 10:401-11. [PMID: 26579919 DOI: 10.1021/ct400663s] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Hydrating water molecules are believed to be an inherent part of the RNA structure and have a considerable impact on RNA conformation. However, the magnitude and mechanism of the interplay between water molecules and the RNA structure are still poorly understood. In principle, such hydration effects can be studied by molecular dynamics (MD) simulations. In our recent MD studies, we observed that the choice of water model has a visible impact on the predicted structure and structural dynamics of RNA and, in particular, has a larger effect than type, parametrization, and concentration of the ions. Furthermore, the water model effect is sequence dependent and modulates the sequence dependence of A-RNA helical parameters. Clearly, the sensitivity of A-RNA structural dynamics to the water model parametrization is a rather spurious effect that complicates MD studies of RNA molecules. These results nevertheless suggest that the sequence dependence of the A-RNA structure, usually attributed to base stacking, might be driven by the structural dynamics of specific hydration. Here, we present a systematic MD study that aimed to (i) clarify the atomistic mechanism of the water model sensitivity and (ii) discover whether and to what extent specific hydration modulates the A-RNA structural variability. We carried out an extended set of MD simulations of canonical A-RNA duplexes with TIP3P, TIP4P/2005, TIP5P, and SPC/E explicit water models and found that different water models provided a different extent of water bridging between 2'-OH groups across the minor groove, which in turn influences their distance and consequently also inclination, roll, and slide parameters. Minor groove hydration is also responsible for the sequence dependence of these helical parameters. Our simulations suggest that TIP5P is not optimal for RNA simulations.
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Affiliation(s)
- Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , tr. 17. Listopadu 12, 771 46, Olomouc, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , tr. 17. Listopadu 12, 771 46, Olomouc, Czech Republic.,Institute of Biophysics, Academy of Sciences of the Czech Republic , Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Kralovopolska 135, 612 65 Brno, Czech Republic.,CEITEC - Central European Institute of Technology , Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , tr. 17. Listopadu 12, 771 46, Olomouc, Czech Republic.,Institute of Biophysics, Academy of Sciences of the Czech Republic , Kralovopolska 135, 612 65 Brno, Czech Republic
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21
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Nguyen CN, Kurtzman T, Gilson MK. Spatial Decomposition of Translational Water-Water Correlation Entropy in Binding Pockets. J Chem Theory Comput 2015; 12:414-29. [PMID: 26636620 PMCID: PMC4819442 DOI: 10.1021/acs.jctc.5b00939] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
A number
of computational tools available today compute the thermodynamic properties
of water at surfaces and in binding pockets by using inhomogeneous
solvation theory (IST) to analyze explicit-solvent simulations. Such
methods enable qualitative spatial mappings of both energy and entropy
around a solute of interest and can also be applied quantitatively.
However, the entropy estimates of existing methods have, to date,
been almost entirely limited to the first-order terms in the IST’s
entropy expansion. These first-order terms account for localization
and orientation of water molecules in the field of the solute but
not for the modification of water–water correlations by the
solute. Here, we present an extension of the Grid Inhomogeneous Solvation
Theory (GIST) approach which accounts for water–water translational
correlations. The method involves rewriting the two-point density
of water in terms of a conditional density and utilizes the efficient
nearest-neighbor entropy estimation approach. Spatial maps of this
second order term, for water in and around the synthetic host cucurbit[7]uril
and in the binding pocket of the enzyme Factor Xa, reveal mainly negative
contributions, indicating solute-induced water–water correlations
relative to bulk water; particularly strong signals are obtained for
sites at the entrances of cavities or pockets. This second-order term
thus enters with the same, negative, sign as the first order translational
and orientational terms. Numerical and convergence properties of the
methodology are examined.
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Affiliation(s)
- Crystal N Nguyen
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego , 9500 Gilman Drive, La Jolla, California 92093-0736, United States
| | - Tom Kurtzman
- Department of Chemistry, Lehman College, The City University of New York , 250 Bedford Park Blvd. West, Bronx, New York, New York 10468, United States.,Ph.D. Program in Chemistry, The Graduate Center of The City University of New York , New York 10016, United States
| | - Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego , 9500 Gilman Drive, La Jolla, California 92093-0736, United States
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22
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Velez-Vega C, McKay DJJ, Kurtzman T, Aravamuthan V, Pearlstein RA, Duca JS. Estimation of Solvation Entropy and Enthalpy via Analysis of Water Oxygen-Hydrogen Correlations. J Chem Theory Comput 2015; 11:5090-102. [PMID: 26574307 DOI: 10.1021/acs.jctc.5b00439] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A statistical-mechanical framework for estimation of solvation entropies and enthalpies is proposed, which is based on the analysis of water as a mixture of correlated water oxygens and water hydrogens. Entropic contributions of increasing order are cast in terms of a Mutual Information Expansion that is evaluated to pairwise interactions. In turn, the enthalpy is computed directly from a distance-based hydrogen bonding energy algorithm. The resulting expressions are employed for grid-based analyses of Molecular Dynamics simulations. In this first assessment of the methodology, we obtained global estimates of the excess entropy and enthalpy of water that are in good agreement with experiment and examined the method's ability to enable detailed elucidation of solvation thermodynamic structures, which can provide valuable knowledge toward molecular design.
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Affiliation(s)
- Camilo Velez-Vega
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Daniel J J McKay
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Tom Kurtzman
- Department of Chemistry, Lehman College, The City University of New York , 250 Bedford Park Boulevard West, Bronx, New York 10468, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York , New York, New York 10016, United States
| | - Vibhas Aravamuthan
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Robert A Pearlstein
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - José S Duca
- Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Institutes for BioMedical Research , 100 Technology Square, Cambridge, Massachusetts 02139, United States
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23
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Bayden AS, Moustakas DT, Joseph-McCarthy D, Lamb ML. Evaluating Free Energies of Binding and Conservation of Crystallographic Waters Using SZMAP. J Chem Inf Model 2015; 55:1552-65. [DOI: 10.1021/ci500746d] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Alexander S. Bayden
- Oncology and Infection Innovative Medicines Units, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Demetri T. Moustakas
- Oncology and Infection Innovative Medicines Units, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Diane Joseph-McCarthy
- Oncology and Infection Innovative Medicines Units, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Michelle L. Lamb
- Oncology and Infection Innovative Medicines Units, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
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24
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Nittinger E, Schneider N, Lange G, Rarey M. Evidence of Water Molecules—A Statistical Evaluation of Water Molecules Based on Electron Density. J Chem Inf Model 2015; 55:771-83. [DOI: 10.1021/ci500662d] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Eva Nittinger
- Center
for Bioinformatics, University of Hamburg, Bundesstraße 43, 20146 Hamburg, Germany
| | - Nadine Schneider
- Center
for Bioinformatics, University of Hamburg, Bundesstraße 43, 20146 Hamburg, Germany
| | - Gudrun Lange
- Bayer CropScience AG, Industriepark
Hoechst, G836, 65926 Frankfurt am Main, Germany
| | - Matthias Rarey
- Center
for Bioinformatics, University of Hamburg, Bundesstraße 43, 20146 Hamburg, Germany
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25
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Sinha SK, Jana M, Chakraborty K, Bandyopadhyay S. In silico studies of the properties of water hydrating a small protein. J Chem Phys 2014; 141:22D502. [DOI: 10.1063/1.4895533] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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26
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Man PP, Bonhomme C, Babonneau F. Denoising NMR time-domain signal by singular-value decomposition accelerated by graphics processing units. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2014; 61-62:28-34. [PMID: 24880899 DOI: 10.1016/j.ssnmr.2014.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/30/2014] [Accepted: 05/08/2014] [Indexed: 06/03/2023]
Abstract
We present a post-processing method that decreases the NMR spectrum noise without line shape distortion. As a result the signal-to-noise (S/N) ratio of a spectrum increases. This method is called Cadzow enhancement procedure that is based on the singular-value decomposition of time-domain signal. We also provide software whose execution duration is a few seconds for typical data when it is executed in modern graphic-processing unit. We tested this procedure not only on low sensitive nucleus (29)Si in hybrid materials but also on low gyromagnetic ratio, quadrupole nucleus (87)Sr in reference sample Sr(NO3)2. Improving the spectrum S/N ratio facilitates the determination of T/Q ratio of hybrid materials. It is also applicable to simulated spectrum, resulting shorter simulation duration for powder averaging. An estimation of the number of singular values needed for denoising is also provided.
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Affiliation(s)
- Pascal P Man
- Sorbonne Universités, UPMC Univ Paris 06, FR 2482, Institut des matériaux de Paris-Centre, Collège de France, F-75005 Paris, France; CNRS, FR 2482, Institut des matériaux de Paris-Centre, Collège de France, F-75005 Paris, France.
| | - Christian Bonhomme
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, F-75005 Paris, France; CNRS, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, F-75005 Paris, France
| | - Florence Babonneau
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, F-75005 Paris, France; CNRS, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, F-75005 Paris, France
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27
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Mikulskis P, Genheden S, Ryde U. Effect of explicit water molecules on ligand-binding affinities calculated with the MM/GBSA approach. J Mol Model 2014; 20:2273. [DOI: 10.1007/s00894-014-2273-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 04/24/2014] [Indexed: 12/24/2022]
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28
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Huggins DJ. Comparing distance metrics for rotation using the k-nearest neighbors algorithm for entropy estimation. J Comput Chem 2014; 35:377-85. [PMID: 24311273 PMCID: PMC4238811 DOI: 10.1002/jcc.23504] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 11/08/2013] [Accepted: 11/14/2013] [Indexed: 01/17/2023]
Abstract
Distance metrics facilitate a number of methods for statistical analysis. For statistical mechanical applications, it is useful to be able to compute the distance between two different orientations of a molecule. However, a number of distance metrics for rotation have been employed, and in this study, we consider different distance metrics and their utility in entropy estimation using the k-nearest neighbors (KNN) algorithm. This approach shows a number of advantages over entropy estimation using a histogram method, and the different approaches are assessed using uniform randomly generated data, biased randomly generated data, and data from a molecular dynamics (MD) simulation of bulk water. The results identify quaternion metrics as superior to a metric based on the Euler angles. However, it is demonstrated that samples from MD simulation must be independent for effective use of the KNN algorithm and this finding impacts any application to time series data.
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Affiliation(s)
- David J Huggins
- Theory of Condensed Matter Group, University of Cambridge, Cavendish Laboratory19 J J Thomson Avenue, Cambridge, CB3 0HE, United Kingdom
- Cambridge Molecular Therapeutics Programme, University of Cambridge, Hutchison/MRC Research CentreHills Road, Cambridge, CB2 0XZ, United Kingdom
- Department of Chemistry, University of CambridgeLensfield Road, Cambridge, UK CB2 1EW, United Kingdom
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29
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Gerogiokas G, Calabro G, Henchman RH, Southey MWY, Law RJ, Michel J. Prediction of Small Molecule Hydration Thermodynamics with Grid Cell Theory. J Chem Theory Comput 2013; 10:35-48. [PMID: 26579889 DOI: 10.1021/ct400783h] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
An efficient methodology has been developed to quantify water energetics by analysis of explicit solvent molecular simulations of organic and biomolecular systems. The approach, grid cell theory (GCT), relies on a discretization of the cell theory methodology on a three-dimensional grid to spatially resolve the density, enthalpy, and entropy of water molecules in the vicinity of solute(s) of interest. Entropies of hydration are found to converge more efficiently than enthalpies of hydration. GCT predictions of free energies of hydration on a data set of small molecules are strongly correlated with thermodynamic integration predictions. Agreement with the experiment is comparable for both approaches. A key advantage of GCT is its ability to provide from a single simulation insightful graphical analyses of spatially resolved components of the enthalpies and entropies of hydration.
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Affiliation(s)
- Georgios Gerogiokas
- EaStCHEM School of Chemistry , Joseph Black Building, The King's Buildings, Edinburgh EH9 3JJ, United Kingdom
| | - Gaetano Calabro
- EaStCHEM School of Chemistry , Joseph Black Building, The King's Buildings, Edinburgh EH9 3JJ, United Kingdom
| | - Richard H Henchman
- Manchester Institute of Biotechnology, The University of Manchester , 131 Princess Street, Manchester M1 7DN, United Kingdom and School of Chemistry, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Michelle W Y Southey
- Evotec (U.K.) Ltd. , 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4SA, United Kingdom
| | - Richard J Law
- Evotec (U.K.) Ltd. , 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4SA, United Kingdom
| | - Julien Michel
- EaStCHEM School of Chemistry , Joseph Black Building, The King's Buildings, Edinburgh EH9 3JJ, United Kingdom
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30
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Haider K, Huggins DJ. Combining solvent thermodynamic profiles with functionality maps of the Hsp90 binding site to predict the displacement of water molecules. J Chem Inf Model 2013; 53:2571-86. [PMID: 24070451 PMCID: PMC3840717 DOI: 10.1021/ci4003409] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Intermolecular interactions in the aqueous phase must compete with the interactions between the two binding partners and their solvating water molecules. In biological systems, water molecules in protein binding sites cluster at well-defined hydration sites and can form strong hydrogen-bonding interactions with backbone and side-chain atoms. Displacement of such water molecules is only favorable when the ligand can form strong compensating hydrogen bonds. Conversely, water molecules in hydrophobic regions of protein binding sites make only weak interactions, and the requirements for favorable displacement are less stringent. The propensity of water molecules for displacement can be identified using inhomogeneous fluid solvation theory (IFST), a statistical mechanical method that decomposes the solvation free energy of a solute into the contributions from different spatial regions and identifies potential binding hotspots. In this study, we employed IFST to study the displacement of water molecules from the ATP binding site of Hsp90, using a test set of 103 ligands. The predicted contribution of a hydration site to the hydration free energy was found to correlate well with the observed displacement. Additionally, we investigated if this correlation could be improved by using the energetic scores of favorable probe groups binding at the location of hydration sites, derived from a multiple copy simultaneous search (MCSS) method. The probe binding scores were not highly predictive of the observed displacement and did not improve the predictivity when used in combination with IFST-based hydration free energies. The results show that IFST alone can be used to reliably predict the observed displacement of water molecules in Hsp90. However, MCSS can augment IFST calculations by suggesting which functional groups should be used to replace highly displaceable water molecules. Such an approach could be very useful in improving the hit-to-lead process for new drug targets.
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Affiliation(s)
- Kamran Haider
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences , Lahore, 54792, Pakistan
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31
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Huggins DJ, Payne MC. Assessing the accuracy of inhomogeneous fluid solvation theory in predicting hydration free energies of simple solutes. J Phys Chem B 2013; 117:8232-44. [PMID: 23763625 PMCID: PMC3756531 DOI: 10.1021/jp4042233] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Accurate
prediction of hydration free energies is a key objective
of any free energy method that is applied to modeling and understanding
interactions in the aqueous phase. Inhomogeneous fluid solvation theory
(IFST) is a statistical mechanical method for calculating solvation
free energies by quantifying the effect of a solute acting as a perturbation
to bulk water. IFST has found wide application in understanding hydration
phenomena in biological systems, but quantitative applications have
not been comprehensively assessed. In this study, we report the hydration
free energies of six simple solutes calculated using IFST and independently
using free energy perturbation (FEP). This facilitates a validation
of IFST that is independent of the accuracy of the force field. The
results demonstrate that IFST shows good agreement with FEP, with
an R2 coefficient of determination of
0.99 and a mean unsigned difference of 0.7 kcal/mol. However, sampling
is a major issue that plagues IFST calculations and the results suggest
that a histogram method may require prohibitively long simulations
to achieve convergence of the entropies, for bin sizes which effectively
capture the underlying probability distributions. Results also highlight
the sensitivity of IFST to the reference interaction energy of a water
molecule in bulk, with a difference of 0.01 kcal/mol changing the
predicted hydration free energies by approximately 2.4 kcal/mol for
the systems studied here. One of the major advantages of IFST over
perturbation methods such as FEP is that the systems are spatially
decomposed to consider the contribution of specific regions to the
total solvation free energies. Visualizing these contributions can
yield detailed insights into solvation thermodynamics. An insight
from this work is the identification and explanation of regions with
unfavorable free energy density relative to bulk water. These regions
contribute unfavorably to the hydration free energy. Further work
is necessary before IFST can be extended to yield accurate predictions
of binding free energies, but the work presented here demonstrates
its potential.
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Affiliation(s)
- David J Huggins
- Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, 19 J J Thomson Avenue, Cambridge CB3 0HE, UK.
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