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Hofer TS, Hünenberger PH. Absolute proton hydration free energy, surface potential of water, and redox potential of the hydrogen electrode from first principles: QM/MM MD free-energy simulations of sodium and potassium hydration. J Chem Phys 2018; 148:222814. [DOI: 10.1063/1.5000799] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Thomas S. Hofer
- Theoretical Chemistry Division, Institute of General, Inorganic and Theoretical Chemistry, Centre for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
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Dos Santos AM, Lima AH, Alves CN, Lameira J. Unraveling the Addition-Elimination Mechanism of EPSP Synthase through Computer Modeling. J Phys Chem B 2017; 121:8626-8637. [PMID: 28829128 DOI: 10.1021/acs.jpcb.7b05063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Enolpyruvyl transfer from phosphoenolpyruvate (PEP) to the hydroxyl group of shikimate-5-OH-3-phosphate (S3P) is catalyzed by 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase in a reaction that involves breaking the C-O bond of PEP. Catalysis involves an addition-elimination mechanism with the formation of a tetrahedral intermediate (THI). Experiments have elucidated the mechanism of THI formation and breakdown. However, the catalytic action of EPSP synthase and the individual roles of catalytic residues Asp313 and Glu341 remains unclear. We have used a hybrid quantum mechanical/molecular mechanical (QM/MM) approach to explore the free energy surface in a reaction catalyzed by EPSP synthase. The Glu341 was the most favorable acid/base catalyst. Our results indicate that the protonation of PEP C3 precedes the nucleophilic attack on PEP C2 in the addition mechanism. Also, the breaking of the C-O bond of THI to form an EPSP cation intermediate must occur before proton transfer from PEP C3 to Glu341 in the elimination mechanism. Analysis of the FES supports cationic intermediate formation during the reaction catalyzed by EPSP synthase. Finally, the computational model indicates a proton transfer shift (Hammond shift) from Glu341 to C3 for an enzyme-based reaction with the shifted transition state, earlier than in the reference reaction in water.
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Affiliation(s)
- Alberto M Dos Santos
- Institute of Biological Sciences, Federal University of Pará , Belém, PA 66075-110, Brazil
| | - Anderson H Lima
- Institute of Biological Sciences, Federal University of Pará , Belém, PA 66075-110, Brazil
| | - Cláudio Nahum Alves
- Institute of Exact and Natural Sciences, Federal University of Pará , Belém, PA 66075-110, Brazil
| | - Jerônimo Lameira
- Institute of Biological Sciences, Federal University of Pará , Belém, PA 66075-110, Brazil
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Kumar S, Plotnikov NV, Rouse JC, Singh SK. Biopharmaceutical Informatics: supporting biologic drug development via molecular modelling and informatics. J Pharm Pharmacol 2017; 70:595-608. [DOI: 10.1111/jphp.12700] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 12/29/2016] [Indexed: 12/23/2022]
Abstract
Abstract
Objectives
The purpose of this article is to introduce an emerging field called ‘Biopharmaceutical Informatics’. It describes how tools from Information technology and Molecular Biophysics can be adapted, developed and gainfully employed in discovery and development of biologic drugs.
Key Findings
The findings described here are based on literature surveys and the authors’ collective experiences in the field of biologic drug product development. A strategic framework to forecast early the hurdles faced during drug product development is weaved together and elucidated using chemical degradation as an example. Efficiency of translating biologic drug discoveries into drug products can be significantly improved by combining learnings from experimental biophysical and analytical data on the drug candidates with molecular properties computed from their sequences and structures via molecular modeling and simulations.
Summary
Biopharmaceutical Informatics seeks to promote applications of computational tools towards discovery and development of biologic drugs. When fully implemented, industry-wide, it will enable rapid materials-free developability assessments of biologic drug candidates at early stages as well as streamline drug product development activities such as commercial scale production, purification, formulation, analytical characterization, safety and in vivo performance.
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Affiliation(s)
- Sandeep Kumar
- Pharmaceutical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Chesterfield, MO, USA
| | - Nikolay V Plotnikov
- Pharmaceutical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Chesterfield, MO, USA
| | - Jason C Rouse
- Analytical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, MA, USA
| | - Satish K Singh
- Pharmaceutical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Chesterfield, MO, USA
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Plotnikov NV, Singh SK, Rouse JC, Kumar S. Quantifying the Risks of Asparagine Deamidation and Aspartate Isomerization in Biopharmaceuticals by Computing Reaction Free-Energy Surfaces. J Phys Chem B 2017; 121:719-730. [DOI: 10.1021/acs.jpcb.6b11614] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Nikolay V. Plotnikov
- Pharmaceutical
Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., 700 Chesterfield Pkwy West, Chesterfield, Missouri 63017, United States
| | - Satish Kumar Singh
- Pharmaceutical
Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., 700 Chesterfield Pkwy West, Chesterfield, Missouri 63017, United States
| | - Jason C. Rouse
- Analytical
Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., 1 Burtt Road, Andover, Massachusetts 01810, United States
| | - Sandeep Kumar
- Pharmaceutical
Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., 700 Chesterfield Pkwy West, Chesterfield, Missouri 63017, United States
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Lu X, Fang D, Ito S, Okamoto Y, Ovchinnikov V, Cui Q. QM/MM free energy simulations: recent progress and challenges. MOLECULAR SIMULATION 2016; 42:1056-1078. [PMID: 27563170 DOI: 10.1080/08927022.2015.1132317] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Due to the higher computational cost relative to pure molecular mechanical (MM) simulations, hybrid quantum mechanical/molecular mechanical (QM/MM) free energy simulations particularly require a careful consideration of balancing computational cost and accuracy. Here we review several recent developments in free energy methods most relevant to QM/MM simulations and discuss several topics motivated by these developments using simple but informative examples that involve processes in water. For chemical reactions, we highlight the value of invoking enhanced sampling technique (e.g., replica-exchange) in umbrella sampling calculations and the value of including collective environmental variables (e.g., hydration level) in metadynamics simulations; we also illustrate the sensitivity of string calculations, especially free energy along the path, to various parameters in the computation. Alchemical free energy simulations with a specific thermodynamic cycle are used to probe the effect of including the first solvation shell into the QM region when computing solvation free energies. For cases where high-level QM/MM potential functions are needed, we analyze two different approaches: the QM/MM-MFEP method of Yang and co-workers and perturbative correction to low-level QM/MM free energy results. For the examples analyzed here, both approaches seem productive although care needs to be exercised when analyzing the perturbative corrections.
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Affiliation(s)
- Xiya Lu
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Dong Fang
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Shingo Ito
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Yuko Okamoto
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Victor Ovchinnikov
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Boston, MA 02138
| | - Qiang Cui
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
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Giese TJ, York DM. Ambient-Potential Composite Ewald Method for ab Initio Quantum Mechanical/Molecular Mechanical Molecular Dynamics Simulation. J Chem Theory Comput 2016; 12:2611-32. [PMID: 27171914 DOI: 10.1021/acs.jctc.6b00198] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A new approach for performing Particle Mesh Ewald in ab initio quantum mechanical/molecular mechanical (QM/MM) simulations with extended atomic orbital basis sets is presented. The new approach, the Ambient-Potential Composite Ewald (CEw) method, does not perform the QM/MM interaction with Mulliken charges nor electrostatically fit charges. Instead the nuclei and electron density interact directly with the MM environment, but in a manner that avoids the use of dense Fourier transform grids. By performing the electrostatics with the underlying QM density, the CEw method avoids self-consistent field instabilities that have been encountered with simple charge mapping procedures. Potential of mean force (PMF) profiles of the p-nitrophenyl phosphate dissociation reaction in explicit solvent are computed from PBE0/6-31G* QM/MM molecular dynamics simulations with various electrostatic protocols. The CEw profiles are shown to be stable with respect to real-space Ewald cutoff, whereas the PMFs computed from truncated and switched electrostatics produce artifacts. PBE0/6-311G**, AM1/d-PhoT, and DFTB2 QM/MM simulations are performed to generate two-dimensional PMF profiles of the phosphoryl transesterification reactions with ethoxide and phenoxide leaving groups. The semiempirical models incorrectly produce a concerted ethoxide mechanism, whereas PBE0 correctly produces a stepwise mechanism. The ab initio reaction barriers agree more closely to experiment than the semiempirical models. The failure of Mulliken-charge QM/MM-Ewald is analyzed.
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Affiliation(s)
- Timothy J Giese
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University , Piscataway, New Jersey 08854-8087, United States
| | - Darrin M York
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University , Piscataway, New Jersey 08854-8087, United States
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Lameira J, Kupchencko I, Warshel A. Enhancing Paradynamics for QM/MM Sampling of Enzymatic Reactions. J Phys Chem B 2016; 120:2155-64. [PMID: 26866994 PMCID: PMC5380004 DOI: 10.1021/acs.jpcb.5b11966] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite the enormous increase in computer power, it is still extremely challenging to obtain computationally converging sampling of ab initio QM/MM (QM(ai)/MM) free energy surfaces in condensed phases. The sampling problem can be significantly reduced by the use of the reference potential paradynamics (PD) approach, but even this approach still requires major computer time in studies of enzymatic reactions. To further reduce the sampling problem we developed here a new PD version where we use an empirical valence bond reference potential that has a minimum rather than a maximum at the transition state region of the target potential (this is accomplished conveniently by shifting the EVB of the product state). Hence, we can map the TS region in a more efficient way. Here, we introduce and validate the inverted EVB PD approach. The validation involves the study of the S(N)2 step of the reaction catalyzed by haloakene dehalogenase (DhlA) and the GTP hydrolysis in the RasGAP system. In addition, we have also studied the corresponding reaction in water for each of the systems described here and the reaction involving trimethylsulfonium and dimethylamine in solution. The results are encouraging and the new strategy appears to provide a powerful way of evaluating QM(ai)/MM activation free energies.
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Affiliation(s)
- Jerônimo Lameira
- Department of Chemistry (SGM418), University of Southern California , 3620 McClintock Avenue, Los Angeles, California 90089, United States
- Faculdade de Biotecnologia e Laboratório de Planejamento e Desenvolvimento de Fármacos, Universidade Federal do Pará , 66075-110, Belém, Pará, Brazil
| | - Ilya Kupchencko
- Department of Chemistry (SGM418), University of Southern California , 3620 McClintock Avenue, Los Angeles, California 90089, United States
| | - Arieh Warshel
- Department of Chemistry (SGM418), University of Southern California , 3620 McClintock Avenue, Los Angeles, California 90089, United States
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Shurki A, Derat E, Barrozo A, Kamerlin SCL. How valence bond theory can help you understand your (bio)chemical reaction. Chem Soc Rev 2015; 44:1037-52. [DOI: 10.1039/c4cs00241e] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This Tutorial Review describes modern VB theory, using a didactic example of an SN2 reaction to illustrate its immediate applications.
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Affiliation(s)
- Avital Shurki
- Institute for Drug Research
- School of Pharmacy
- The Hebrew University of Jerusalem
- Jerusalem
- Israel
| | - Etienne Derat
- Institut Parisien de Chimie Moléculaire
- UMR 8232
- Paris
- France
| | - Alexandre Barrozo
- Science for Life Laboratory
- Department of Cell and Molecular Biology
- Uppsala University
- Uppsala
- Sweden
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Recent advances in QM/MM free energy calculations using reference potentials. Biochim Biophys Acta Gen Subj 2014; 1850:954-965. [PMID: 25038480 PMCID: PMC4547088 DOI: 10.1016/j.bbagen.2014.07.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Revised: 07/06/2014] [Accepted: 07/07/2014] [Indexed: 01/02/2023]
Abstract
Background Recent years have seen enormous progress in the development of methods for modeling (bio)molecular systems. This has allowed for the simulation of ever larger and more complex systems. However, as such complexity increases, the requirements needed for these models to be accurate and physically meaningful become more and more difficult to fulfill. The use of simplified models to describe complex biological systems has long been shown to be an effective way to overcome some of the limitations associated with this computational cost in a rational way. Scope of review Hybrid QM/MM approaches have rapidly become one of the most popular computational tools for studying chemical reactivity in biomolecular systems. However, the high cost involved in performing high-level QM calculations has limited the applicability of these approaches when calculating free energies of chemical processes. In this review, we present some of the advances in using reference potentials and mean field approximations to accelerate high-level QM/MM calculations. We present illustrative applications of these approaches and discuss challenges and future perspectives for the field. Major conclusions The use of physically-based simplifications has shown to effectively reduce the cost of high-level QM/MM calculations. In particular, lower-level reference potentials enable one to reduce the cost of expensive free energy calculations, thus expanding the scope of problems that can be addressed. General significance As was already demonstrated 40 years ago, the usage of simplified models still allows one to obtain cutting edge results with substantially reduced computational cost. This article is part of a Special Issue entitled Recent developments of molecular dynamics. We present some of the advances to accelerate high-level QM/MM calculations. Quantitative limitations of low-level methods can be overcome by these approaches. Reference potentials make free energy simulations feasible for large systems. Automated fitting reduces the need of expensive sampling of high-level approaches. Application of reference potentials can be extended to a wide range of processes.
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