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The Relevance of Experimental Charge Density Analysis in Unraveling Noncovalent Interactions in Molecular Crystals. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123690. [PMID: 35744821 PMCID: PMC9229234 DOI: 10.3390/molecules27123690] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/22/2022] [Accepted: 05/29/2022] [Indexed: 11/17/2022]
Abstract
The work carried out by our research group over the last couple of decades in the context of quantitative crystal engineering involves the analysis of intermolecular interactions such as carbon (tetrel) bonding, pnicogen bonding, chalcogen bonding, and halogen bonding using experimental charge density methodology is reviewed. The focus is to extract electron density distribution in the intermolecular space and to obtain guidelines to evaluate the strength and directionality of such interactions towards the design of molecular crystals with desired properties. Following the early studies on halogen bonding interactions, several "sigma-hole" interaction types with similar electrostatic origins have been explored in recent times for their strength, origin, and structural consequences. These include interactions such as carbon (tetrel) bonding, pnicogen bonding, chalcogen bonding, and halogen bonding. Experimental X-ray charge density analysis has proved to be a powerful tool in unraveling the strength and electronic origin of such interactions, providing insights beyond the theoretical estimates from gas-phase molecular dimer calculations. In this mini-review, we outline some selected contributions from the X-ray charge density studies to the field of non-covalent interactions (NCIs) involving elements of the groups 14-17 of the periodic table. Quantitative insights into the nature of these interactions obtained from the experimental electron density distribution and subsequent topological analysis by the quantum theory of atoms in molecules (QTAIM) have been discussed. A few notable examples of weak interactions have been presented in terms of their experimental charge density features. These examples reveal not only the strength and beauty of X-ray charge density multipole modeling as an advanced structural chemistry tool but also its utility in providing experimental benchmarks for the theoretical studies of weak interactions in crystals.
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2
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Correy GJ, Kneller DW, Phillips G, Pant S, Russi S, Cohen AE, Meigs G, Holton JM, Gahbauer S, Thompson MC, Ashworth A, Coates L, Kovalevsky A, Meilleur F, Fraser JS. The mechanisms of catalysis and ligand binding for the SARS-CoV-2 NSP3 macrodomain from neutron and x-ray diffraction at room temperature. SCIENCE ADVANCES 2022; 8:eabo5083. [PMID: 35622909 PMCID: PMC9140965 DOI: 10.1126/sciadv.abo5083] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 04/11/2022] [Indexed: 05/04/2023]
Abstract
The nonstructural protein 3 (NSP3) macrodomain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Mac1) removes adenosine diphosphate (ADP) ribosylation posttranslational modifications, playing a key role in the immune evasion capabilities of the virus responsible for the coronavirus disease 2019 pandemic. Here, we determined neutron and x-ray crystal structures of the SARS-CoV-2 NSP3 macrodomain using multiple crystal forms, temperatures, and pHs, across the apo and ADP-ribose-bound states. We characterize extensive solvation in the Mac1 active site and visualize how water networks reorganize upon binding of ADP-ribose and non-native ligands, inspiring strategies for displacing waters to increase the potency of Mac1 inhibitors. Determining the precise orientations of active site water molecules and the protonation states of key catalytic site residues by neutron crystallography suggests a catalytic mechanism for coronavirus macrodomains distinct from the substrate-assisted mechanism proposed for human MacroD2. These data provoke a reevaluation of macrodomain catalytic mechanisms and will guide the optimization of Mac1 inhibitors.
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Affiliation(s)
- Galen J. Correy
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Daniel W. Kneller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
| | - Gwyndalyn Phillips
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
| | - Swati Pant
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
| | - Silvia Russi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Aina E. Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - George Meigs
- Department of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - James M. Holton
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stefan Gahbauer
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Michael C. Thompson
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA 95343, USA
| | - Alan Ashworth
- Helen Diller Family Comprehensive Cancer, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Leighton Coates
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
- Second Target Station, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
| | - Flora Meilleur
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - James S. Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
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3
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Correy GJ, Kneller DW, Phillips G, Pant S, Russi S, Cohen AE, Meigs G, Holton JM, Gahbauer S, Thompson MC, Ashworth A, Coates L, Kovalevsky A, Meilleur F, Fraser JS. The mechanisms of catalysis and ligand binding for the SARS-CoV-2 NSP3 macrodomain from neutron and X-ray diffraction at room temperature. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.02.07.479477. [PMID: 35169801 PMCID: PMC8845425 DOI: 10.1101/2022.02.07.479477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The NSP3 macrodomain of SARS CoV 2 (Mac1) removes ADP-ribosylation post-translational modifications, playing a key role in the immune evasion capabilities of the virus responsible for the COVID-19 pandemic. Here, we determined neutron and X-ray crystal structures of the SARS-CoV-2 NSP3 macrodomain using multiple crystal forms, temperatures, and pHs, across the apo and ADP-ribose-bound states. We characterize extensive solvation in the Mac1 active site, and visualize how water networks reorganize upon binding of ADP-ribose and non-native ligands, inspiring strategies for displacing waters to increase potency of Mac1 inhibitors. Determining the precise orientations of active site water molecules and the protonation states of key catalytic site residues by neutron crystallography suggests a catalytic mechanism for coronavirus macrodomains distinct from the substrate-assisted mechanism proposed for human MacroD2. These data provoke a re-evaluation of macrodomain catalytic mechanisms and will guide the optimization of Mac1 inhibitors.
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Affiliation(s)
- Galen J Correy
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA
| | - Daniel W Kneller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Gwyndalyn Phillips
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Swati Pant
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Silvia Russi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Center, Menlo Park, CA 94025, USA
| | - Aina E Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Center, Menlo Park, CA 94025, USA
| | - George Meigs
- Department of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94158, USA
| | - James M Holton
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Center, Menlo Park, CA 94025, USA
- Department of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94158, USA
| | - Stefan Gahbauer
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Michael C Thompson
- Department of Chemistry and Chemical Biology, University of California Merced, CA 95343, USA
| | - Alan Ashworth
- Helen Diller Family Comprehensive Cancer, University of California San Francisco, CA 94158, USA
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Flora Meilleur
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA
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4
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Hsu N, Wang Y, Lin K, Chang C, Ke S, Lyu S, Hsu L, Li Y, Chen S, Wang K, Li T. Evidence of Diradicals Involved in the Yeast Transketolase Catalyzed Keto-Transferring Reactions. Chembiochem 2018; 19:2395-2402. [PMID: 30155962 PMCID: PMC6282555 DOI: 10.1002/cbic.201800378] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Indexed: 11/12/2022]
Abstract
Transketolase (TK) catalyzes a reversible transfer of a two-carbon (C2 ) unit between phosphoketose donors and phosphoaldose acceptors, for which the group-transfer reaction that follows a one- or two-electron mechanism and the force that breaks the C2"-C3" bond of the ketose donors remain unresolved. Herein, we report ultrahigh-resolution crystal structures of a TK (TKps) from Pichia stipitis in previously undiscovered intermediate states and support a diradical mechanism for a reversible group-transfer reaction. In conjunction with MS, NMR spectroscopy, EPR and computational analyses, it is concluded that the enzyme-catalyzed non-Kekulé diradical cofactor brings about the C2"-C3" bond cleavage/formation for the C2 -unit transfer reaction, for which suppression of activation energy and activation and destabilization of enzymatic intermediates are facilitated.
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Affiliation(s)
- Ning‐Shian Hsu
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
- Institute of Biochemistry and Molecular BiologyNational Yang-Ming UniversityTaipei112Taiwan
| | - Yung‐Lin Wang
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | - Kuan‐Hung Lin
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
- Institute of Biochemistry and Molecular BiologyNational Yang-Ming UniversityTaipei112Taiwan
| | - Chi‐Fon Chang
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | - Shyue‐Chu Ke
- Department of PhysicsNational Dong Hwa UniversityHualien974Taiwan
| | - Syue‐Yi Lyu
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | - Li‐Jen Hsu
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | - Yi‐Shan Li
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | | | | | - Tsung‐Lin Li
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
- Biotechnology CenterNational Chung Hsing UniversityTaichung City402Taiwan
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5
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Masuda T, Okubo K, Murata K, Mikami B, Sugahara M, Suzuki M, Temussi PA, Tani F. Subatomic structure of hyper-sweet thaumatin D21N mutant reveals the importance of flexible conformations for enhanced sweetness. Biochimie 2018; 157:57-63. [PMID: 30389513 DOI: 10.1016/j.biochi.2018.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/26/2018] [Indexed: 01/26/2023]
Abstract
One of the sweetest proteins found in tropical fruits (with a threshold of 50 nM), thaumatin, is also used commercially as a sweetener. Our previous study successfully produced the sweetest thaumatin mutant (D21N), designated hyper-sweet thaumatin, which decreases the sweetness threshold to 31 nM. To investigate why the D21N mutant is sweeter than wild-type thaumatin, we compared the structure of the D21N mutant solved at a subatomic resolution of 0.93 Å with that of wild-type thaumatin determined at 0.90 Å. Although the overall structure of the D21N mutant resembles that of wild-type thaumatin, our subatomic resolution analysis successfully assigned and discriminated the detailed atomic positions of side-chains at position 21. The relative B-factor value of the side-chain at position 21 in the D21N mutant was higher than that of wild-type thaumatin, hinting at a greater flexibility of side-chain at 21 in the hyper-sweet D21N mutant. Furthermore, alternative conformations of Lys19, which is hydrogen-bonded to Asp21 in wild-type, were found only in the D21N mutant. Subatomic resolution analysis revealed that flexible conformations at the sites adjacent to positions 19 and 21 play a crucial role in enhancing sweet potency and may serve to enhance the complementarity of electrostatic potentials for interaction with the sweet taste receptor.
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Affiliation(s)
- Tetsuya Masuda
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan.
| | - Kyohei Okubo
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Kazuki Murata
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Bunzo Mikami
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Michihiro Sugahara
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Mamoru Suzuki
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Piero Andrea Temussi
- Department of Basic and Clinical Neurosciences, King's College London, London, SE59RX, UK; Dipartimento di Chimica, Universita' di Napoli Federico II, Napoli, I-80126, Italy
| | - Fumito Tani
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
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6
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Masuda T, Suzuki M, Inoue S, Song C, Nakane T, Nango E, Tanaka R, Tono K, Joti Y, Kameshima T, Hatsui T, Yabashi M, Mikami B, Nureki O, Numata K, Iwata S, Sugahara M. Atomic resolution structure of serine protease proteinase K at ambient temperature. Sci Rep 2017; 7:45604. [PMID: 28361898 PMCID: PMC5374539 DOI: 10.1038/srep45604] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/01/2017] [Indexed: 01/24/2023] Open
Abstract
Atomic resolution structures (beyond 1.20 Å) at ambient temperature, which is usually hampered by the radiation damage in synchrotron X-ray crystallography (SRX), will add to our understanding of the structure-function relationships of enzymes. Serial femtosecond crystallography (SFX) has attracted surging interest by providing a route to bypass such challenges. Yet the progress on atomic resolution analysis with SFX has been rather slow. In this report, we describe the 1.20 Å resolution structure of proteinase K using 13 keV photon energy. Hydrogen atoms, water molecules, and a number of alternative side-chain conformations have been resolved. The increase in the value of B-factor in SFX suggests that the residues and water molecules adjacent to active sites were flexible and exhibited dynamic motions at specific substrate-recognition sites.
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Affiliation(s)
- Tetsuya Masuda
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.,RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Mamoru Suzuki
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shigeyuki Inoue
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Changyong Song
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,Department of Physics, POSTECH, Pohang 790-784, Korea
| | - Takanori Nakane
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Eriko Nango
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Rie Tanaka
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Yasumasa Joti
- Japan Synchrotron Radiation Research Institute, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Takashi Kameshima
- Japan Synchrotron Radiation Research Institute, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Takaki Hatsui
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Makina Yabashi
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Bunzo Mikami
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Keiji Numata
- Enzyme Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science, Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - So Iwata
- RIKEN SPring-8 Center, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
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7
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Dittrich B, Matta CF. Contributions of charge-density research to medicinal chemistry. IUCRJ 2014; 1:457-69. [PMID: 25485126 PMCID: PMC4224464 DOI: 10.1107/s2052252514018867] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 08/20/2014] [Indexed: 06/04/2023]
Abstract
This article reviews efforts in accurate experimental charge-density studies with relevance to medicinal chemistry. Initially, classical charge-density studies that measure electron density distribution via least-squares refinement of aspherical-atom population parameters are summarized. Next, interaction density is discussed as an idealized situation resembling drug-receptor interactions. Scattering-factor databases play an increasing role in charge-density research, and they can be applied both to small-molecule and macromolecular structures in refinement and analysis; software development facilitates their use. Therefore combining both of these complementary branches of X-ray crystallography is recommended, and examples are given where such a combination already proved useful. On the side of the experiment, new pixel detectors are allowing rapid measurements, thereby enabling both high-throughput small-molecule studies and macromolecular structure determination to higher resolutions. Currently, the most ambitious studies compute intermolecular interaction energies of drug-receptor complexes, and it is recommended that future studies benefit from recent method developments. Selected new developments in theoretical charge-density studies are discussed with emphasis on its symbiotic relation to crystallography.
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Affiliation(s)
- Birger Dittrich
- Institut für Anorganische und Angewandte Chemie, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Chérif F. Matta
- Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, Nova Scotia B3M 2J6, Canada
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4J3M, Canada
- Department of Chemistry, Saint Mary’s University, Halifax, Nova Scotia B3H 3C3, Canada
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8
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Higashiura A, Ohta K, Masaki M, Sato M, Inaka K, Tanaka H, Nakagawa A. High-resolution X-ray crystal structure of bovine H-protein using the high-pressure cryocooling method. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:989-93. [PMID: 24121354 PMCID: PMC3795570 DOI: 10.1107/s090904951302373x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/22/2013] [Indexed: 06/02/2023]
Abstract
Recently, many technical improvements in macromolecular X-ray crystallography have increased the number of structures deposited in the Protein Data Bank and improved the resolution limit of protein structures. Almost all high-resolution structures have been determined using a synchrotron radiation source in conjunction with cryocooling techniques, which are required in order to minimize radiation damage. However, optimization of cryoprotectant conditions is a time-consuming and difficult step. To overcome this problem, the high-pressure cryocooling method was developed (Kim et al., 2005) and successfully applied to many protein-structure analyses. In this report, using the high-pressure cryocooling method, the X-ray crystal structure of bovine H-protein was determined at 0.86 Å resolution. Structural comparisons between high- and ambient-pressure cryocooled crystals at ultra-high resolution illustrate the versatility of this technique. This is the first ultra-high-resolution X-ray structure obtained using the high-pressure cryocooling method.
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Affiliation(s)
- Akifumi Higashiura
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kazunori Ohta
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan
| | - Mika Masaki
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan
| | - Masaru Sato
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan
| | - Koji Inaka
- Maruwa Foods and Biosciences Inc., Nara 639-1123, Japan
| | | | - Atsushi Nakagawa
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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9
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Smoum R, Rubinstein A, Dembitsky VM, Srebnik M. Boron containing compounds as protease inhibitors. Chem Rev 2012; 112:4156-220. [PMID: 22519511 DOI: 10.1021/cr608202m] [Citation(s) in RCA: 298] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Reem Smoum
- The School of Pharmacy, Institute for Drug Research, The Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem, Israel.
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10
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Afonine PV, Grosse-Kunstleve RW, Echols N, Headd JJ, Moriarty NW, Mustyakimov M, Terwilliger TC, Urzhumtsev A, Zwart PH, Adams PD. Towards automated crystallographic structure refinement with phenix.refine. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:352-67. [PMID: 22505256 PMCID: PMC3322595 DOI: 10.1107/s0907444912001308] [Citation(s) in RCA: 3955] [Impact Index Per Article: 329.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 01/11/2012] [Indexed: 11/10/2022]
Abstract
phenix.refine is a program within the PHENIX package that supports crystallographic structure refinement against experimental data with a wide range of upper resolution limits using a large repertoire of model parameterizations. It has several automation features and is also highly flexible. Several hundred parameters enable extensive customizations for complex use cases. Multiple user-defined refinement strategies can be applied to specific parts of the model in a single refinement run. An intuitive graphical user interface is available to guide novice users and to assist advanced users in managing refinement projects. X-ray or neutron diffraction data can be used separately or jointly in refinement. phenix.refine is tightly integrated into the PHENIX suite, where it serves as a critical component in automated model building, final structure refinement, structure validation and deposition to the wwPDB. This paper presents an overview of the major phenix.refine features, with extensive literature references for readers interested in more detailed discussions of the methods.
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Affiliation(s)
- Pavel V Afonine
- Lawrence Berkeley National Laboratory, One Cyclotron Road, MS64R0121, Berkeley, CA 94720, USA.
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11
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Wahlgren WY, Pál G, Kardos J, Porrogi P, Szenthe B, Patthy A, Gráf L, Katona G. The catalytic aspartate is protonated in the Michaelis complex formed between trypsin and an in vitro evolved substrate-like inhibitor: a refined mechanism of serine protease action. J Biol Chem 2010; 286:3587-96. [PMID: 21097875 PMCID: PMC3030363 DOI: 10.1074/jbc.m110.161604] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The mechanism of serine proteases prominently illustrates how charged amino acid residues and proton transfer events facilitate enzyme catalysis. Here we present an ultrahigh resolution (0.93 Å) x-ray structure of a complex formed between trypsin and a canonical inhibitor acting through a substrate-like mechanism. The electron density indicates the protonation state of all catalytic residues where the catalytic histidine is, as expected, in its neutral state prior to the acylation step by the catalytic serine. The carboxyl group of the catalytic aspartate displays an asymmetric electron density so that the Oδ2–Cγ bond appears to be a double bond, with Oδ2 involved in a hydrogen bond to His-57 and Ser-214. Only when Asp-102 is protonated on Oδ1 atom could a density functional theory simulation reproduce the observed electron density. The presence of a putative hydrogen atom is also confirmed by a residual mFobs − DFcalc density above 2.5 σ next to Oδ1. As a possible functional role for the neutral aspartate in the active site, we propose that in the substrate-bound form, the neutral aspartate residue helps to keep the pKa of the histidine sufficiently low, in the active neutral form. When the histidine receives a proton during the catalytic cycle, the aspartate becomes simultaneously negatively charged, providing additional stabilization for the protonated histidine and indirectly to the tetrahedral intermediate. This novel proposal unifies the seemingly conflicting experimental observations, which were previously seen as either supporting the charge relay mechanism or the neutral pKa histidine theory.
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Affiliation(s)
- Weixiao Yuan Wahlgren
- Department of Chemistry, University of Gothenburg, Medicinaregatan 9C, 40530 Gothenburg, Sweden
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12
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Higashiura A, Kurakane T, Matsuda M, Suzuki M, Inaka K, Sato M, Kobayashi T, Tanaka T, Tanaka H, Fujiwara K, Nakagawa A. High-resolution X-ray crystal structure of bovine H-protein at 0.88 A resolution. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:698-708. [PMID: 20516622 DOI: 10.1107/s0907444910010668] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 03/22/2010] [Indexed: 11/11/2022]
Abstract
Recent technical improvements in macromolecular X-ray crystallography have significantly improved the resolution limit of protein structures. However, examples of high-resolution structure determination are still limited. In this study, the X-ray crystal structure of bovine H-protein, a component of the glycine cleavage system, was determined at 0.88 A resolution. This is the first ultrahigh-resolution structure of an H-protein. The data were collected using synchrotron radiation. Because of limitations of the hardware, especially the dynamic range of the CCD detector, three data sets (high-, medium- and low-resolution data sets) were measured in order to obtain a complete set of data. To improve the quality of the merged data, the reference data set was optimized for merging and the merged data were assessed by comparing merging statistics and R factors against the final model and the number of visualized H atoms. In addition, the advantages of merging three data sets were evaluated. The omission of low-resolution reflections had an adverse effect on visualization of H atoms in hydrogen-omit maps. Visualization of hydrogen electron density is a good indicator for assessing the quality of high-resolution X-ray diffraction data.
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13
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Takeda K, Kusumoto K, Hirano Y, Miki K. Detailed assessment of X-ray induced structural perturbation in a crystalline state protein. J Struct Biol 2010; 169:135-44. [DOI: 10.1016/j.jsb.2009.09.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 09/14/2009] [Accepted: 09/21/2009] [Indexed: 10/20/2022]
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14
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Parente A, Berisio R, Chambery A, Di Maro A. Type 1 Ribosome-Inactivating Proteins from the Ombú Tree (Phytolacca dioica L.). TOXIC PLANT PROTEINS 2010. [DOI: 10.1007/978-3-642-12176-0_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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15
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Dittrich B, Bond CS, Kalinowski R, Spackman MA, Jayatilaka D. Revised electrostatics from invariom refinement of the 18-residue peptaibol antibiotic trichotoxin A50E. CrystEngComm 2010. [DOI: 10.1039/c001072c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Sigala PA, Kraut DA, Caaveiro JMM, Pybus B, Ruben EA, Ringe D, Petsko GA, Herschlag D. Testing geometrical discrimination within an enzyme active site: constrained hydrogen bonding in the ketosteroid isomerase oxyanion hole. J Am Chem Soc 2008; 130:13696-708. [PMID: 18808119 DOI: 10.1021/ja803928m] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enzymes are classically proposed to accelerate reactions by binding substrates within active-site environments that are structurally preorganized to optimize binding interactions with reaction transition states rather than ground states. This is a remarkably formidable task considering the limited 0.1-1 A scale of most substrate rearrangements. The flexibility of active-site functional groups along the coordinate of substrate rearrangement, the distance scale on which enzymes can distinguish structural rearrangement, and the energetic significance of discrimination on that scale remain open questions that are fundamental to a basic physical understanding of enzyme active sites and catalysis. We bring together 1.2-1.5 A resolution X-ray crystallography, (1)H and (19)F NMR spectroscopy, quantum mechanical calculations, and transition-state analogue binding measurements to test the distance scale on which noncovalent forces can constrain the structural relaxation or translation of side chains and ligands along a specific coordinate and the energetic consequences of such geometric constraints within the active site of bacterial ketosteroid isomerase (KSI). Our results strongly suggest that packing and binding interactions within the KSI active site can constrain local side-chain reorientation and prevent hydrogen bond shortening by 0.1 A or less. Further, this constraint has substantial energetic effects on ligand binding and stabilization of negative charge within the oxyanion hole. These results provide evidence that subtle geometric effects, indistinguishable in most X-ray crystallographic structures, can have significant energetic consequences and highlight the importance of using synergistic experimental approaches to dissect enzyme function.
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Affiliation(s)
- Paul A Sigala
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
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17
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Ruggiero A, Chambery A, Maro AD, Parente A, Berisio R. Atomic resolution (1.1 Å) structure of the ribosome-inactivating protein PD-L4 fromPhytolacca dioicaL. leaves. Proteins 2008; 71:8-15. [DOI: 10.1002/prot.21712] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Afonine PV, Grosse-Kunstleve RW, Adams PD, Lunin VY, Urzhumtsev A. On macromolecular refinement at subatomic resolution with interatomic scatterers. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2007; 63:1194-7. [PMID: 18007035 PMCID: PMC2808317 DOI: 10.1107/s0907444907046148] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 09/20/2007] [Indexed: 05/25/2023]
Abstract
Modelling deformation electron density using interatomic scatters is simpler than multipolar methods, produces comparable results at subatomic resolution and can easily be applied to macromolecules. A study of the accurate electron-density distribution in molecular crystals at subatomic resolution (better than ∼1.0 Å) requires more detailed models than those based on independent spherical atoms. A tool that is conventionally used in small-molecule crystallography is the multipolar model. Even at upper resolution limits of 0.8–1.0 Å, the number of experimental data is insufficient for full multipolar model refinement. As an alternative, a simpler model composed of conventional independent spherical atoms augmented by additional scatterers to model bonding effects has been proposed. Refinement of these mixed models for several benchmark data sets gave results that were comparable in quality with the results of multipolar refinement and superior to those for conventional models. Applications to several data sets of both small molecules and macromolecules are shown. These refinements were performed using the general-purpose macromolecular refinement module phenix.refine of the PHENIX package.
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Affiliation(s)
- Pavel V Afonine
- Lawrence Berkeley National Laboratory, One Cyclotron Road, BLDG 64R0121, Berkeley, CA 94720, USA.
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19
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Kong GKW, Adams JJ, Cappai R, Parker MW. Structure of Alzheimer's disease amyloid precursor protein copper-binding domain at atomic resolution. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:819-24. [PMID: 17909280 PMCID: PMC2339725 DOI: 10.1107/s1744309107041139] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Accepted: 08/20/2007] [Indexed: 01/31/2023]
Abstract
Amyloid precursor protein (APP) plays a central role in the pathogenesis of Alzheimer's disease, as its cleavage generates the Abeta peptide that is toxic to cells. APP is able to bind Cu2+ and reduce it to Cu+ through its copper-binding domain (CuBD). The interaction between Cu2+ and APP leads to a decrease in Abeta production and to alleviation of the symptoms of the disease in mouse models. Structural studies of CuBD have been undertaken in order to better understand the mechanism behind the process. Here, the crystal structure of CuBD in the metal-free form determined to ultrahigh resolution (0.85 A) is reported. The structure shows that the copper-binding residues of CuBD are rather rigid but that Met170, which is thought to be the electron source for Cu2+ reduction, adopts two different side-chain conformations. These observations shed light on the copper-binding and redox mechanisms of CuBD. The structure of CuBD at atomic resolution provides an accurate framework for structure-based design of molecules that will deplete Abeta production.
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Affiliation(s)
- Geoffrey Kwai-Wai Kong
- Biota Structural Biology Laboratory, St Vincent’s Institute, 9 Princes Street, Fitzroy, Victoria 3065, Australia
| | - Julian J. Adams
- Biota Structural Biology Laboratory, St Vincent’s Institute, 9 Princes Street, Fitzroy, Victoria 3065, Australia
| | - Roberto Cappai
- Department of Pathology and Centre for Neuroscience, The University of Melbourne, Victoria 3010, Australia
- The Mental Health Research Institute of Victoria, Parkville, Victoria 3052, Australia
- Bio21 Institute, The University of Melbourne, Victoria 3010, Australia
| | - Michael W. Parker
- Biota Structural Biology Laboratory, St Vincent’s Institute, 9 Princes Street, Fitzroy, Victoria 3065, Australia
- Bio21 Institute, The University of Melbourne, Victoria 3010, Australia
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20
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Gsponer J, Hopearuoho H, Cavalli A, Dobson CM, Vendruscolo M. Geometry, energetics, and dynamics of hydrogen bonds in proteins: structural information derived from NMR scalar couplings. J Am Chem Soc 2007; 128:15127-35. [PMID: 17117864 DOI: 10.1021/ja0614722] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An accurate description of hydrogen bonds is essential to identify the determinants of protein stability and function as well as folding and misfolding behavior. We describe a method of using J couplings through hydrogen bonds as ensemble-averaged restraints in molecular dynamics simulations. Applications to the cases of ubiquitin and protein G show that these scalar couplings provide powerful structural information that, when used through the methodology that we present here, enables the description of the geometry and energetics of hydrogen bonds with an accuracy approaching that of high-resolution X-ray structures.
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Affiliation(s)
- Joerg Gsponer
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
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21
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Huang X, Zheng F, Crooks PA, Dwoskin L, Zhan CG. Modeling multiple species of nicotine and deschloroepibatidine interacting with alpha4beta2 nicotinic acetylcholine receptor: from microscopic binding to phenomenological binding affinity. J Am Chem Soc 2005; 127:14401-14. [PMID: 16218635 PMCID: PMC3182463 DOI: 10.1021/ja052681+] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A variety of molecular modeling, molecular docking, and first-principles electronic structure calculations were performed to study how the alpha4beta2 nicotinic acetylcholine receptor (nAChR) binds with different species of two typical agonists, (S)-(-)-nicotine and (R)-(-)-deschloroepibatidine, each of which is distinguished by different free bases and protonation states. On the basis of these results, predictions were made regarding the corresponding microscopic binding free energies. Hydrogen-bonding and cation-pi interactions between the receptor and the respective ligands were found to be the dominant factors differentiating the binding strengths of different microscopic binding species. The calculated results and analyses demonstrate that, for each agonist, all the species are interchangeable and can quickly achieve a thermodynamic equilibrium in solution and at the nAChR binding site. This allows quantitation of the equilibrium concentration distributions of the free ligand species and the corresponding microscopic ligand-receptor binding species, their pH dependence, and their contributions to the phenomenological binding affinity. The predicted equilibrium concentration distributions, pK(a) values, absolute phenomenological binding affinities, and their pH dependence are all in good agreement with available experimental data, suggesting that the computational strategy from the microscopic binding species and affinities to the phenomenological binding affinity is reliable for studying alpha4beta2 nAChR-ligand binding. This should provide valuable information for future rational design of drugs targeting nAChRs. The general strategy of the "from-microscopic-to-phenomenological" approach for studying interactions of alpha4beta2 nAChRs with (S)-(-)-nicotine and (R)-(-)-deschloroepibatidine may also be useful in studying other types of ligand-protein interactions involving multiple molecular species of a ligand and in associated rational drug design.
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Affiliation(s)
- Xiaoqin Huang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, Kentucky 40536
| | - Fang Zheng
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, Kentucky 40536
| | - Peter A. Crooks
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, Kentucky 40536
| | - Linda Dwoskin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, Kentucky 40536
| | - Chang-Guo Zhan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, Kentucky 40536
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22
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Forrest LR, Honig B. An assessment of the accuracy of methods for predicting hydrogen positions in protein structures. Proteins 2005; 61:296-309. [PMID: 16114036 DOI: 10.1002/prot.20601] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The addition of hydrogen atoms to models or experimental structures of proteins that contain only non-hydrogen atoms is a common step in crystallographic structure refinement, in theoretical studies of proteins, and in protein structure prediction. Accurate prediction of the hydrogen positions is essential, since they constitute around half of the atoms in proteins and hence contribute significantly to their energetics. Many computational tools exist for predicting hydrogen positions, although to date no quantitative comparison has been made of their accuracy or efficiency. Here we take advantage of the recent increase in ultra-high-resolution X-ray crystal structures (< 0.9 A resolution), as well as of a number of relatively high-resolution neutron diffraction structures (< 1.8 A resolution), to compare the quality of the predictions generated by a large set of commonly used methods. These include CHARMM, CNS, GROMACS, MCCE, MolProbity, WHAT IF, and X-PLOR. The hydrogen atoms that lack a rotational degree of freedom are mostly, but not always, accurately predicted. For hydrogens with a rotational degree of freedom, all the methods give much less accurate predictions. The predictions for the hydroxyl hydrogens are analyzed in detail, particularly those buried within the protein, and some explanation is provided for the errors observed. The results provide a means to make informed decisions regarding the choice and implementation of methodologies for placing hydrogens on structures of proteins. They also point to shortcomings in current force fields and suggest the need for improved descriptions of hydrogen bonding energetics.
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Affiliation(s)
- Lucy R Forrest
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA
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23
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Jarmelo S, Maiti N, Anderson V, Carey PR, Fausto R. Cα−H Bond-Stretching Frequency in Alcohols as a Probe of Hydrogen-Bonding Strength: A Combined Vibrational Spectroscopic and Theoretical Study of n-[1-D]Propanol. J Phys Chem A 2005; 109:2069-77. [PMID: 16838977 DOI: 10.1021/jp046683c] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The sensitivity of the nu(C)()alpha(-)(H/D) vibrational stretching frequency to hydrogen bonding in alcohols is examined by infrared and Raman spectroscopy, supported by DFT(B3LYP)/6-311++G(d,p) calculations. The model compound studied is (R,S)-n-[1-D]propanol. It is shown that the nu(C)()alpha(-)(H/D) mode can be successfully correlated with the hydrogen-bond strength in a given solvent, provided the O-H group involved in the hydrogen bond is not acting simultaneously as a hydrogen-bond donor and acceptor. In addition, a detailed analysis of the spectroscopic features observed in both the nu(O)(-)(H) and nu(C)()alpha(-)(H/D) spectral regions of the spectra of n-propanol and (R,S)-n-[1-D]propanol, in a series of different experimental conditions, which include the matrix-isolated compound (in argon matrix), pure liquid and low-temperature glassy states, and solution in different solvents, is undertaken. This permits the contribution of the different conformers of the studied compounds to be assigned to the bands observed in the nu(O)(-)(H) and nu(C)(-)(H) spectral regions.
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Affiliation(s)
- S Jarmelo
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
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24
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Wada M, Sakurai M. A quantum chemical method for rapid optimization of protein structures. J Comput Chem 2004; 26:160-8. [PMID: 15586398 DOI: 10.1002/jcc.20154] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A quantum chemical method for rapid optimization of protein structures is proposed. In this method, a protein structure is treated as an assembly of amino acid units, and the geometry optimization of each unit is performed with taking the effect of its surrounding environment into account. The optimized geometry of a whole protein is obtained by repeated application of such a local optimization procedure over the entire part of the protein. Here, we implemented this method in the MOPAC program and performed geometry optimization for three different sizes of proteins. Consequently, these results demonstrate that the total energies of the proteins are much efficiently minimized compared with the use of conventional optimization methods, including the MOZYME algorithm (a representative linear-scaling method) with the BFGS routine. The proposed method is superior to the conventional methods in both CPU time and memory requirements.
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Affiliation(s)
- Mitsuhito Wada
- Makuhari R&D Center, Celestar Lexico-Sciences, Inc., Makuhari Techno Garden D17, 1-3 Nakase, Mihama-ku, Chiba 261-8501, Japan
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