1
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Mudryk K, Lee C, Tomaník L, Malerz S, Trinter F, Hergenhahn U, Neumark DM, Slavíček P, Bradforth S, Winter B. How Does Mg 2+(aq) Interact with ATP (aq)? Biomolecular Structure through the Lens of Liquid-Jet Photoemission Spectroscopy. J Am Chem Soc 2024; 146:16062-16075. [PMID: 38802319 PMCID: PMC11177255 DOI: 10.1021/jacs.4c03174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 05/29/2024]
Abstract
Liquid-jet photoemission spectroscopy (LJ-PES) allows for a direct probing of electronic structure in aqueous solutions. We show the applicability of the approach to biomolecules in a complex environment, exploring site-specific information on the interaction of adenosine triphosphate in the aqueous phase (ATP(aq)) with magnesium (Mg2+(aq)), highlighting the synergy brought about by the simultaneous analysis of different regions in the photoelectron spectrum. In particular, we demonstrate intermolecular Coulombic decay (ICD) spectroscopy as a new and powerful addition to the arsenal of techniques for biomolecular structure investigation. We apply LJ-PES assisted by electronic-structure calculations to study ATP(aq) solutions with and without dissolved Mg2+. Valence photoelectron data reveal spectral changes in the phosphate and adenine features of ATP(aq) due to interactions with the divalent cation. Chemical shifts in Mg 2p, Mg 2s, P 2p, and P 2s core-level spectra as a function of the Mg2+/ATP concentration ratio are correlated to the formation of [Mg(ATP) 2]6-(aq), [MgATP]2-(aq), and [Mg2ATP](aq) complexes, demonstrating the element sensitivity of the technique to Mg2+-phosphate interactions. The most direct probe of the intermolecular interactions between ATP(aq) and Mg2+(aq) is delivered by the emerging ICD electrons following ionization of Mg 1s electrons. ICD spectra are shown to sensitively probe ligand exchange in the Mg2+-ATP(aq) coordination environment. In addition, we report and compare P 2s data from ATP(aq) and adenosine mono- and diphosphate (AMP(aq) and ADP(aq), respectively) solutions, probing the electronic structure of the phosphate chain and the local environment of individual phosphate units in ATP(aq). Our results provide a comprehensive view of the electronic structure of ATP(aq) and Mg2+-ATP(aq) complexes relevant to phosphorylation and dephosphorylation reactions that are central to bioenergetics in living organisms.
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Affiliation(s)
- Karen Mudryk
- Fritz-Haber-Institut
der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Chin Lee
- Fritz-Haber-Institut
der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Lukáš Tomaník
- Department
of Physical Chemistry, University of Chemistry
and Technology, Prague, Technická 5, Prague 6 16628, Czech Republic
| | - Sebastian Malerz
- Fritz-Haber-Institut
der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Florian Trinter
- Fritz-Haber-Institut
der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
- Institut
für Kernphysik, Goethe-Universität
Frankfurt, Max-von-Laue-Straße
1, 60438 Frankfurt
am Main, Germany
| | - Uwe Hergenhahn
- Fritz-Haber-Institut
der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Daniel M. Neumark
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Petr Slavíček
- Department
of Physical Chemistry, University of Chemistry
and Technology, Prague, Technická 5, Prague 6 16628, Czech Republic
| | - Stephen Bradforth
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Bernd Winter
- Fritz-Haber-Institut
der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
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2
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DeLuca M, Sensale S, Lin PA, Arya G. Prediction and Control in DNA Nanotechnology. ACS APPLIED BIO MATERIALS 2024; 7:626-645. [PMID: 36880799 DOI: 10.1021/acsabm.2c01045] [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] [Indexed: 03/08/2023]
Abstract
DNA nanotechnology is a rapidly developing field that uses DNA as a building material for nanoscale structures. Key to the field's development has been the ability to accurately describe the behavior of DNA nanostructures using simulations and other modeling techniques. In this Review, we present various aspects of prediction and control in DNA nanotechnology, including the various scales of molecular simulation, statistical mechanics, kinetic modeling, continuum mechanics, and other prediction methods. We also address the current uses of artificial intelligence and machine learning in DNA nanotechnology. We discuss how experiments and modeling are synergistically combined to provide control over device behavior, allowing scientists to design molecular structures and dynamic devices with confidence that they will function as intended. Finally, we identify processes and scenarios where DNA nanotechnology lacks sufficient prediction ability and suggest possible solutions to these weak areas.
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Affiliation(s)
- Marcello DeLuca
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States
| | - Sebastian Sensale
- Department of Physics, Cleveland State University, Cleveland, Ohio 44115, United States
| | - Po-An Lin
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States
| | - Gaurav Arya
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States
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3
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Silverstein TP. The real reason why ATP hydrolysis is spontaneous at pH > 7: It's (mostly) the proton concentration! BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION : A BIMONTHLY PUBLICATION OF THE INTERNATIONAL UNION OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 51:476-485. [PMID: 37278404 DOI: 10.1002/bmb.21745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 04/14/2023] [Accepted: 05/11/2023] [Indexed: 06/07/2023]
Abstract
Common wisdom holds that ATP hydrolysis is spontaneous because of the weakness of its phosphoanhydride bonds, electrostatic repulsion within the polyanionic ATP4- molecule, and resonance stabilization of the inorganic phosphate and ADP products. By examining the pH-dependence of the hydrolysis Gibbs free energy, we show that in fact, above pH 7, ATP hydrolysis is spontaneous due mainly to the low concentration of the H+ that is released as product. Hence, ATP is essentially just an electrophilic target whose attack by H2 O causes the acidity of the water nucleophile to increase dramatically; the spontaneity of the resulting acid ionization supplies much of the released Gibbs free energy. We also find that fermentation lowers pH not due to its organic acid products (e.g., lactic, acetic, formic, or succinic acids), but again, due to the H+ product of ATP hydrolysis.
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4
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Persichetti JR, Jiang Y, Hudson PS, O'Brien EP. Modeling Ensembles of Enzyme Reaction Pathways with Hi-MSM Reveals the Importance of Accounting for Pathway Diversity. J Phys Chem B 2022; 126:9748-9758. [PMID: 36383711 PMCID: PMC11260359 DOI: 10.1021/acs.jpcb.2c04496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Conventional quantum mechanical-molecular mechanics (QM/MM) simulation approaches for modeling enzyme reactions often assume that there is one dominant reaction pathway and that this pathway can be sampled starting from an X-ray structure of the enzyme. These assumptions reduce computational cost; however, their validity has not been extensively tested. This is due in part to the lack of a rigorous formalism for integrating disparate pathway information from dynamical QM/MM calculations. Here, we present a way to model ensembles of reaction pathways efficiently using a divide-and-conquer strategy through Hierarchical Markov State Modeling (Hi-MSM). This approach allows information on multiple, distinct pathways to be incorporated into a chemical kinetic model, and it allows us to test these two assumptions. Applying Hi-MSM to the reaction carried out by dihydrofolate reductase (DHFR) we find (i) there are multiple, distinct pathways significantly contributing to the overall flux of the reaction that the conventional approach does not identify and (ii) that the conventional approach does not identify the dominant reaction pathway. Thus, both assumptions underpinning the conventional approach are violated. Since DHFR is a relatively small enzyme, and configuration space scales exponentially with protein size, accounting for multiple reaction pathways is likely to be necessary for most enzymes.
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5
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Ogrizek M, Janežič M, Valjavec K, Perdih A. Catalytic Mechanism of ATP Hydrolysis in the ATPase Domain of Human DNA Topoisomerase IIα. J Chem Inf Model 2022; 62:3896-3909. [PMID: 35948041 PMCID: PMC9400105 DOI: 10.1021/acs.jcim.2c00303] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Human DNA topoisomerase IIα is a biological nanomachine
that
regulates the topological changes of the DNA molecule and is considered
a prime target for anticancer drugs. Despite intensive research, many
atomic details about its mechanism of action remain unknown. We investigated
the ATPase domain, a segment of the human DNA topoisomerase IIα,
using all-atom molecular simulations, multiscale quantum mechanics/molecular
mechanics (QM/MM) calculations, and a point mutation study. The results
suggested that the binding of ATP affects the overall dynamics of
the ATPase dimer. Reaction modeling revealed that ATP hydrolysis favors
the dissociative substrate-assisted reaction mechanism with the catalytic
Glu87 serving to properly position and polarize the lytic water molecule.
The point mutation study complemented our computational results, demonstrating
that Lys378, part of the important QTK loop, acts as a stabilizing
residue. The work aims to pave the way to a deeper understanding of
these important molecular motors and to advance the development of
new therapeutics.
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Affiliation(s)
- Mitja Ogrizek
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Matej Janežič
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Katja Valjavec
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Andrej Perdih
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia.,Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, SI 1000 Ljubljana, Slovenia
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6
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Penkov NV, Penkova N. Key Differences of the Hydrate Shell Structures of ATP and Mg·ATP Revealed by Terahertz Time-Domain Spectroscopy and Dynamic Light Scattering. J Phys Chem B 2021; 125:4375-4382. [PMID: 33882673 DOI: 10.1021/acs.jpcb.1c02276] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
ATP is one of the main biological molecules. Many of its biological and physicochemical properties, such as energy capacity of the phosphate bonds, significantly depend on hydration. However, the structure of the hydration shell of the ATP molecule is still a matter of discussion. In this work, the hydration shells of ATP in water and MgCl2 solutions were examined by terahertz time-domain spectroscopy and dynamic light scattering. Terahertz spectroscopy reveals the distorted water structure in the ATP water solution displaying tightly bound water molecules, which could be explained by the hydration of phosphate groups. Upon ATP binding to a Mg2+ ion, the situation is principally different: Instead of the distorted water structure, its arranged structure with increased hydrogen bond number is observed. Dynamic light scattering showed that the hydrodynamic diameter of ATP increases by 0.5 nm after Mg2+ binding. Meanwhile, according the characteristics of scattering, the increase of the shell size occurs via formation of a layer with a refraction coefficient similar to water. This layer can be interpreted as hydration shell differing from unaltered water by increased number of hydrogen bonds.
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Affiliation(s)
- Nikita V Penkov
- Institute of Cell Biophysics RAS, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino 142290, Russia
| | - Nadezda Penkova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia
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7
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Buelens FP, Leonov H, de Groot BL, Grubmüller H. ATP-Magnesium Coordination: Protein Structure-Based Force Field Evaluation and Corrections. J Chem Theory Comput 2021; 17:1922-1930. [PMID: 33616388 PMCID: PMC8023659 DOI: 10.1021/acs.jctc.0c01205] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Indexed: 12/29/2022]
Abstract
In the numerous molecular recognition and catalytic processes across biochemistry involving adenosine triphosphate (ATP), the common bioactive form is its magnesium chelate, ATP·Mg2+. In aqueous solution, two chelation geometries predominate, distinguished by bidentate and tridentate Mg2+-phosphate coordination. These are approximately isoenergetic but separated by a high energy barrier. Force field-based atomistic simulation studies of this complex require an accurate representation of its structure and energetics. Here we focused on the energetics of ATP·Mg2+ coordination. Applying an enhanced sampling scheme to circumvent prohibitively slow sampling of transitions between coordination modes, we observed striking contradictions between Amber and CHARMM force field descriptions, most prominently in opposing predictions of the favored coordination mode. Through further configurational free energy calculations, conducted against a diverse set of ATP·Mg2+-protein complex structures to supplement otherwise limited experimental data, we quantified systematic biases for each force field. The force field calculations were strongly predictive of experimentally observed coordination modes, enabling additive corrections to the coordination free energy that deliver close agreement with experiment. We reassessed the applicability of the thus corrected force field descriptions of ATP·Mg2+ for biomolecular simulation and observed that, while the CHARMM parameters display an erroneous preference for overextended triphosphate configurations that will affect many common biomolecular simulation applications involving ATP, the force field energy landscapes broadly agree with experimental measurements of solution geometry and the distribution of ATP·Mg2+ structures found in the Protein Data Bank. Our force field evaluation and correction approach, based on maximizing consistency with the large and heterogeneous collection of structural information encoded in the PDB, should be broadly applicable to many other systems.
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Affiliation(s)
- Floris P. Buelens
- Department
of Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Hadas Leonov
- Computational
Biomolecular Dynamics Group, Max Planck
Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Bert L. de Groot
- Computational
Biomolecular Dynamics Group, Max Planck
Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Helmut Grubmüller
- Department
of Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
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8
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Structural Insight into the Contributions of the N-Terminus and Key Active-Site Residues to the Catalytic Efficiency of Glutamine Synthetase 2. Biomolecules 2020; 10:biom10121671. [PMID: 33327463 PMCID: PMC7764910 DOI: 10.3390/biom10121671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/11/2020] [Accepted: 12/11/2020] [Indexed: 12/20/2022] Open
Abstract
Glutamine synthetase (GS) catalyzes the condensation of ammonia and glutamate, along with ATP, to form glutamine. Despite extensive studies on GSs from eukaryotes and prokaryotes, the roles of the N-terminus and other structural features in catalysis remain unclear. Here we report the decameric structure of Drosophila melanogaster GS 2 (DmGS2). The N-terminal short helices, α1 and α2, constitute a meander region, and form hydrogen bonds with residues 3–5 in the N-terminal loop, which are not present in the GSs of other species. Deletion of α1 or α1-α2 inactivates DmGS2. Notably, the Arg4 in each monomer of one pentamer forms hydrogen bonds with Glu7, and Asp8 in the adjacent monomer of the other pentamer. Replacement of Arg4 with Asp (R4D) abolishes activity. Analytical ultracentrifugation revealed that Arg4 is crucial for oligomerization. Circular dichroism spectra revealed that R4D may alter the secondary structure. We mutated key residues to identify the substrate-binding site. As Glu140 binds glutamate and Glu311 binds ammonia, mutants E140A and E311A have little activity. Conversely, mutant P214A (P contributes to ATP binding) has higher activity than wild-type DmGS2. These findings expand the understanding of the structural and functional features of the N-terminal meander region of DmGS2 and the residues important for catalytic efficiency.
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9
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Calixto AR, Moreira C, Pabis A, Kötting C, Gerwert K, Rudack T, Kamerlin SCL. GTP Hydrolysis Without an Active Site Base: A Unifying Mechanism for Ras and Related GTPases. J Am Chem Soc 2019; 141:10684-10701. [PMID: 31199130 DOI: 10.1021/jacs.9b03193] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
GTP hydrolysis is a biologically crucial reaction, being involved in regulating almost all cellular processes. As a result, the enzymes that catalyze this reaction are among the most important drug targets. Despite their vital importance and decades of substantial research effort, the fundamental mechanism of enzyme-catalyzed GTP hydrolysis by GTPases remains highly controversial. Specifically, how do these regulatory proteins hydrolyze GTP without an obvious general base in the active site to activate the water molecule for nucleophilic attack? To answer this question, we perform empirical valence bond simulations of GTPase-catalyzed GTP hydrolysis, comparing solvent- and substrate-assisted pathways in three distinct GTPases, Ras, Rab, and the Gαi subunit of a heterotrimeric G-protein, both in the presence and in the absence of the corresponding GTPase activating proteins. Our results demonstrate that a general base is not needed in the active site, as the preferred mechanism for GTP hydrolysis is a conserved solvent-assisted pathway. This pathway involves the rate-limiting nucleophilic attack of a water molecule, leading to a short-lived intermediate that tautomerizes to form H2PO4- and GDP as the final products. Our fundamental biochemical insight into the enzymatic regulation of GTP hydrolysis not only resolves a decades-old mechanistic controversy but also has high relevance for drug discovery efforts. That is, revisiting the role of oncogenic mutants with respect to our mechanistic findings would pave the way for a new starting point to discover drugs for (so far) "undruggable" GTPases like Ras.
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Affiliation(s)
- Ana R Calixto
- Department of Chemistry-BMC , Uppsala University , Box 576, S-751 23 Uppsala , Sweden
| | - Cátia Moreira
- Department of Chemistry-BMC , Uppsala University , Box 576, S-751 23 Uppsala , Sweden
| | - Anna Pabis
- Department of Cell and Molecular Biology , Uppsala University , BMC Box 596, S-751 24 , Uppsala , Sweden
| | - Carsten Kötting
- Department of Biophysics , Ruhr University Bochum , 44801 Bochum , Germany
| | - Klaus Gerwert
- Department of Biophysics , Ruhr University Bochum , 44801 Bochum , Germany
| | - Till Rudack
- Department of Biophysics , Ruhr University Bochum , 44801 Bochum , Germany
| | - Shina C L Kamerlin
- Department of Chemistry-BMC , Uppsala University , Box 576, S-751 23 Uppsala , Sweden
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10
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Huang W, Huang Y, Xu J, Liao JL. How Does the Spliceosome Catalyze Intron Lariat Formation? Insights from Quantum Mechanics/Molecular Mechanics Free-Energy Simulations. J Phys Chem B 2019; 123:6049-6055. [DOI: 10.1021/acs.jpcb.9b04377] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Wenting Huang
- Department of Chemical Physics, University of Science and Technology of China, JinZhai Rd. 96, Hefei, Anhui 230026, China
| | - Yan Huang
- Department of Chemical Physics, University of Science and Technology of China, JinZhai Rd. 96, Hefei, Anhui 230026, China
| | - Jun Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Jie-Lou Liao
- Department of Chemical Physics, University of Science and Technology of China, JinZhai Rd. 96, Hefei, Anhui 230026, China
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11
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Sohrabi-Mahboub M, Jahangiri S, Farrokhpour H. Molecular dynamics simulation of the hydration of adenosine phosphates. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.03.085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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12
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Moreno-Del Álamo M, Tabone M, Muñoz-Martínez J, Valverde JR, Alonso JC. Toxin ζ Reduces the ATP and Modulates the Uridine Diphosphate-N-acetylglucosamine Pool. Toxins (Basel) 2019; 11:E29. [PMID: 30634431 PMCID: PMC6356619 DOI: 10.3390/toxins11010029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 12/21/2018] [Accepted: 01/04/2019] [Indexed: 11/20/2022] Open
Abstract
Toxin ζ expression triggers a reversible state of dormancy, diminishes the pool of purine nucleotides, promotes (p)ppGpp synthesis, phosphorylates a fraction of the peptidoglycan precursor uridine diphosphate-N-acetylglucosamine (UNAG), leading to unreactive UNAG-P, induces persistence in a reduced subpopulation, and sensitizes cells to different antibiotics. Here, we combined computational analyses with biochemical experiments to examine the mechanism of toxin ζ action. Free ζ toxin showed low affinity for UNAG. Toxin ζ bound to UNAG hydrolyzed ATP·Mg2+, with the accumulation of ADP, Pi, and produced low levels of phosphorylated UNAG (UNAG-P). Toxin ζ, which has a large ATP binding pocket, may temporally favor ATP binding in a position that is distant from UNAG, hindering UNAG phosphorylation upon ATP hydrolysis. The residues D67, E116, R158 and R171, involved in the interaction with metal, ATP, and UNAG, were essential for the toxic and ATPase activities of toxin ζ; whereas the E100 and T128 residues were partially dispensable. The results indicate that ζ bound to UNAG reduces the ATP concentration, which indirectly induces a reversible dormant state, and modulates the pool of UNAG.
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Affiliation(s)
- María Moreno-Del Álamo
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin Str., 28049 Madrid, Spain.
| | - Mariangela Tabone
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin Str., 28049 Madrid, Spain.
| | - Juan Muñoz-Martínez
- Scientific Computing Service, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin Str., 28049 Madrid, Spain.
| | - José R Valverde
- Scientific Computing Service, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin Str., 28049 Madrid, Spain.
| | - Juan C Alonso
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 3 Darwin Str., 28049 Madrid, Spain.
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13
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Dudev T, Grauffel C, Hsu STD, Lim C. How Native and Non-Native Cations Bind and Modulate the Properties of GTP/ATP. J Chem Theory Comput 2018; 14:3311-3320. [PMID: 29768917 DOI: 10.1021/acs.jctc.8b00259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Adenosine triphosphate (ATP) and guanosine triphosphate (GTP) exist in physiological solution mostly bound to cations. Interestingly, their cellular Mg2+-bound forms have been shown to bind Li+, a first-line drug for bipolar disorder. However, solution structures of NTP/NDP (N = A or G) bound to Li+ and/or Mg2+ have not been solved, thus precluding knowledge of how the native Mg2+-bound cofactor conformation changes upon binding non-native Li+ and/or switching its environment from aqueous solution to proteins. Using well-calibrated methods that reproduce experimental structural and thermodynamic parameters of several Mg2+/Li+-nucleotide complexes, we show that the native NTP/NDP-Mg2+ cofactor adopts a "folded" conformation in water that remains unperturbed upon Li+ binding. We further show that the ATP-binding pockets of receptors such as P2X are complementary in shape to the "folded" ATP-Mg2+ solution structure, whereas the elongated GTP-binding pockets found in G-proteins necessitate the GTP-Mg2+ cofactor to undergo a conformational change from its "folded" conformation in solution to an extended one upon G-protein binding. Implications of the findings on how Li+, in its bound state, can manifest its therapeutic effects are discussed.
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Affiliation(s)
- Todor Dudev
- Faculty of Chemistry and Pharmacy , Sofia University , Sofia 1164 , Bulgaria
| | - Cédric Grauffel
- Institute of Biomedical Sciences , Academia Sinica , Taipei 11529 , Taiwan
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry , Academia Sinica , Taipei 11529 , Taiwan
| | - Carmay Lim
- Institute of Biomedical Sciences , Academia Sinica , Taipei 11529 , Taiwan.,Department of Chemistry , National Tsing Hua University , Hsinchu 300 , Taiwan
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14
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Jongkon N, Gleeson D, Gleeson MP. Elucidation of the catalytic mechanism of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase using QM/MM calculations. Org Biomol Chem 2018; 16:6239-6249. [DOI: 10.1039/c8ob01428k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This account describes the application of QM/MM calculations to understand the reaction mechanism of HPPK, an important pharmacological target on the folate pathway for the treatment of diseases including anti-microbial resistance, malaria and cancer.
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Affiliation(s)
- Nathjanan Jongkon
- Department of Social and Applied Science
- College of Industrial Technology
- King Mongkut's University of Technology North Bangkok
- Bangkok 10800
- Thailand
| | - Duangkamol Gleeson
- Department of Chemistry
- Faculty of Science
- King Mongkut's Institute of Technology Ladkrabang
- Thailand
| | - M. Paul Gleeson
- Department of Biomedical Engineering
- Faculty of Engineering
- King Mongkut's Institute of Technology Ladkrabang
- Bangkok 10520
- Thailand
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15
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Barrozo A, Blaha-Nelson D, Williams NH, Kamerlin SCL. The effect of magnesium ions on triphosphate hydrolysis. PURE APPL CHEM 2017. [DOI: 10.1515/pac-2016-1125] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
AbstractThe role of metal ions in catalyzing phosphate ester hydrolysis has been the subject of much debate, both in terms of whether they change the transition state structure or mechanistic pathway. Understanding the impact of metal ions on these biologically critical reactions is central to improving our understanding of the role of metal ions in the numerous enzymes that facilitate them. In the present study, we have performed density functional theory studies of the mechanisms of methyl triphosphate and acetyl phosphate hydrolysis in aqueous solution to explore the competition between solvent- and substrate-assisted pathways, and examined the impact of Mg2+ on the energetics and transition state geometries. In both cases, we observe a clear preference for a more dissociative solvent-assisted transition state, which is not significantly changed by coordination of Mg2+. The effect of Mg2+ on the transition state geometries for the two pathways is minimal. While our calculations cannot rule out a substrate-assisted pathway as a possible solution for biological phosphate hydrolysis, they demonstrate that a significantly higher energy barrier needs to be overcome in the enzymatic reaction for this to be an energetically viable reaction pathway.
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Affiliation(s)
- Alexandre Barrozo
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-1062, USA
| | - David Blaha-Nelson
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden
| | | | - Shina C. L. Kamerlin
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden
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Takahashi H, Umino S, Miki Y, Ishizuka R, Maeda S, Morita A, Suzuki M, Matubayasi N. Drastic Compensation of Electronic and Solvation Effects on ATP Hydrolysis Revealed through Large-Scale QM/MM Simulations Combined with a Theory of Solutions. J Phys Chem B 2017; 121:2279-2287. [PMID: 28222598 DOI: 10.1021/acs.jpcb.7b00637] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrolysis of adenosine triphosphate (ATP) is the "energy source" for a variety of biochemical processes. In the present work, we address key features of ATP hydrolysis: the relatively moderate value (about -10 kcal/mol) of the standard free energy, ΔGhyd, of reaction and the insensitivity of ΔGhyd to the number of excess electrons on ATP. We conducted quantum mechanical/molecular mechanical simulation combined with the energy-representation theory of solutions to analyze the electronic-state and solvation contributions to ΔGhyd. It was revealed that the electronic-state contribution in ΔGhyd is largely negative (favorable) upon hydrolysis, due to the reduction of electrostatic repulsion accompanying the breakage of the P-O bond. In contrast, the solvation effect was found to be strongly more favorable on the reactant side. Thus, we showed that a drastic compensation of the two opposite effects takes place, leading to the modest value of ΔGhyd at each number of excess electrons examined. The computational analyses were also conducted for pyrophosphate ions (PPi), and the parallelism between the ATP and PPi hydrolyses was confirmed. Classical molecular dynamics simulation was further carried out to discuss the effect of the solvent environment; the insensitivity of ΔGhyd to the number of excess electrons was seen to hold in solvent water and ethanol.
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Affiliation(s)
- Hideaki Takahashi
- Department of Chemistry, Graduate School of Science, Tohoku University , Sendai, Miyagi 980-8578, Japan
| | - Satoru Umino
- Department of Chemistry, Graduate School of Science, Tohoku University , Sendai, Miyagi 980-8578, Japan
| | - Yuji Miki
- Department of Chemistry, Graduate School of Science, Tohoku University , Sendai, Miyagi 980-8578, Japan
| | - Ryosuke Ishizuka
- Department of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan
| | - Shu Maeda
- Department of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan
| | - Akihiro Morita
- Department of Chemistry, Graduate School of Science, Tohoku University , Sendai, Miyagi 980-8578, Japan
| | - Makoto Suzuki
- Department of Materials Processing, Graduate School of Engineering, Tohoku University , Sendai, Miyagi 980-8579, Japan
| | - Nobuyuki Matubayasi
- Department of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan
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17
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Tripathi R, Glaves R, Marx D. The GTPase hGBP1 converts GTP to GMP in two steps via proton shuttle mechanisms. Chem Sci 2017; 8:371-380. [PMID: 28451182 PMCID: PMC5365056 DOI: 10.1039/c6sc02045c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/21/2016] [Indexed: 11/21/2022] Open
Abstract
GTPases play a crucial role in the regulation of many biological processes by catalyzing the hydrolysis of GTP into GDP. The focus of this work is on the dynamin-related large GTPase human guanine nucleotide binding protein-1 (hGBP1) which is able to hydrolyze GTP even to GMP. Here, we studied the largely unknown mechanisms of both GTP and GDP hydrolysis steps utilizing accelerated ab initio QM/MM metadynamics simulations to compute multi-dimensional free energy landscapes. We find an indirect substrate-assisted catalysis (SAC) mechanism for GTP hydrolysis involving transfer of a proton from the water nucleophile to a nonbridging phosphoryl oxygen via a proton relay pathway where the rate-determining first step is concerted-dissociative nature. A "composite base" consisting of Ser73, Glu99, a bridging water molecule, and GTP was found to activate the nucleophilic water, thus disclosing the complex nature of the general base in hGBP1. A nearly two-fold reduction in the free energy barrier was obtained for GTP hydrolysis in the enzyme in comparison to bulk solvent. The subsequent GDP hydrolysis in hGBP1 was also found to follow a water-mediated proton shuttle mechanism. It is expected that the proton shuttle mechanisms unravelled for hGBP1 apply to many classes of GTPases/ATPases that possess an optimally-arranged hydrogen bonding network, which connects the catalytic water to a proton acceptor.
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Affiliation(s)
- Ravi Tripathi
- Lehrstuhl für Theoretische Chemie , Ruhr-Universität Bochum , 44780 Bochum , Germany .
| | - Rachel Glaves
- Lehrstuhl für Theoretische Chemie , Ruhr-Universität Bochum , 44780 Bochum , Germany .
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie , Ruhr-Universität Bochum , 44780 Bochum , Germany .
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18
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Hsu WL, Furuta T, Sakurai M. ATP Hydrolysis Mechanism in a Maltose Transporter Explored by QM/MM Metadynamics Simulation. J Phys Chem B 2016; 120:11102-11112. [PMID: 27712074 DOI: 10.1021/acs.jpcb.6b07332] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Translocation of substrates across the cell membrane by adenosine 5'-triphosphate (ATP)-binding cassette (ABC) transporters depends on the energy provided by ATP hydrolysis within the nucleotide-binding domains (NBDs). However, the detailed mechanism remains unclear. In this study, we focused on maltose transporter NBDs (MalK2) and performed a quantum mechanical/molecular mechanical (QM/MM) well-tempered metadynamics simulation to address this issue. We explored the free-energy profile along an assigned collective variable. As a result, it was determined that the activation free energy is approximately 10.5 kcal/mol, and the reaction released approximately 3.8 kcal/mol of free energy, indicating that the reaction of interest is a one-step exothermic reaction. The dissociation of the ATP γ-phosphate seems to be the rate-limiting step, which supports the so-called dissociative model. Moreover, Glu159, located in the Walker B motif, acts as a base to abstract the proton from the lytic water, but is not the catalytic base, which corresponds to an atypical general base catalysis model. We also observed two interesting proton transfers: transfer from the His192 ε-position nitrogen to the dissociated inorganic phosphate, Pi, and transfer from the Lys42 side chain to adenosine 5'-diphosphate β-phosphate. These proton transfers would stabilize the posthydrolysis state. Our study provides significant insight into the ATP hydrolysis mechanism in MalK2 from a dynamical viewpoint, and this insight would be applicable to other ABC transporters.
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Affiliation(s)
- Wei-Lin Hsu
- Center for Biological Resources and Informatics, Tokyo Institute of Technology , 4259-B-62, Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Tadaomi Furuta
- Center for Biological Resources and Informatics, Tokyo Institute of Technology , 4259-B-62, Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Minoru Sakurai
- Center for Biological Resources and Informatics, Tokyo Institute of Technology , 4259-B-62, Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
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19
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Kiani FA, Fischer S. Effects of protonation on the hydrolysis of triphosphate in vacuum and the implications for catalysis by nucleotide hydrolyzing enzymes. BMC BIOCHEMISTRY 2016; 17:12. [PMID: 27974044 PMCID: PMC5157097 DOI: 10.1186/s12858-016-0068-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/14/2016] [Indexed: 11/15/2022]
Abstract
BACKGROUND Nucleoside triphosphate (NTP) hydrolysis is a key reaction in biology. It involves breaking two very stable bonds (one P-O bond and one O-H bond of water), in either a concurrent or a sequential way. Here, we systematically examine how protonation of the triphosphate affects the mechanism of hydrolysis. RESULTS The hydrolysis reaction of methyl triphosphate in vacuum is computed with protons in various numbers and position on the three phosphate groups. Protonation is seen to have a strong catalytic effect, with the reaction mechanism depending highly on the protonation pattern. CONCLUSION This dependence is apparently complicated, but is shown to obey a well-defined set of rules: Protonation of the α- and β-phosphate groups favors a sequential hydrolysis mechanism, whereas γ-protonation favors a concurrent mechanism, the two effects competing with each other in cases of simultaneous protonation. The rate-limiting step is always the breakup of the water molecule while it attacks the γ-phosphorus, and its barrier is lowered by γ-protonation. This step has significantly lower barriers in the sequential reactions, because the dissociated γ-metaphosphate intermediate (PγO3-) is a much better target for water attack than the un-dissociated γ-phosphate (-PγO42-). The simple chemical logic behind these rules helps to better understand the catalytic strategy used by NTPase enzymes, as illustrated here for the catalytic pocket of myosin. A set of rules was determined that describes how protonating the phosphate groups affects the hydrolysis mechanism of methyl triphosphate: Protonation of the α- and/or β- phosphate groups promotes a sequential mechanism in which P-O bond breaking precedes the breakup of the attacking water, whereas protonation of the γ-phosphate promotes a concurrent mechanism and lowers the rate-limiting barrier of water breakup. The role played by individual protein residues in the catalytic pocket of triphosphate hydrolysing enzymes can be assigned accordingly.
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Affiliation(s)
- Farooq Ahmad Kiani
- Research Center for Modeling and Simulation (RCMS), National University of Sciences and Technology (NUST), Sector H-12, 44000 Islamabad, Pakistan
| | - Stefan Fischer
- Computational Biochemistry, Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Im Neuenheimer Feld 205, D-69120 Heidelberg, Germany
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Huang W, Liao JL. Catalytic Mechanism of the Maltose Transporter Hydrolyzing ATP. Biochemistry 2015; 55:224-31. [PMID: 26666844 DOI: 10.1021/acs.biochem.5b00970] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We use quantum mechanical and molecular mechanical (QM/MM) simulations to study ATP hydrolysis catalyzed by the maltose transporter. This protein is a prototypical member of a large family that consists of ATP-binding cassette (ABC) transporters. The ABC proteins catalyze ATP hydrolysis to perform a variety of biological functions. Despite extensive research efforts, the precise molecular mechanism of ATP hydrolysis catalyzed by the ABC enzymes remains elusive. In this work, the reaction pathway for ATP hydrolysis in the maltose transporter is evaluated using a QM/MM implementation of the nudged elastic band method without presuming reaction coordinates. The potential of mean force along the reaction pathway is obtained with an activation free energy of 19.2 kcal/mol in agreement with experiments. The results demonstrate that the reaction proceeds via a dissociative-like pathway with a trigonal bipyramidal transition state in which the cleavage of the γ-phosphate P-O bond occurs and the O-H bond of the lytic water molecule is not yet broken. Our calculations clearly show that the Walker B glutamate as well as the switch histidine stabilizes the transition state via electrostatic interactions rather than serving as a catalytic base. The results are consistent with biochemical and structural experiments, providing novel insight into the molecular mechanism of ATP hydrolysis in the ABC proteins.
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Affiliation(s)
- Wenting Huang
- Department of Chemical Physics, University of Science and Technology of China , 96 Jinzhai Road, Hefei, Anhui Province, People's Republic of China 230026
| | - Jie-Lou Liao
- Department of Chemical Physics, University of Science and Technology of China , 96 Jinzhai Road, Hefei, Anhui Province, People's Republic of China 230026
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21
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Acosta-Silva C, Bertran J, Branchadell V, Oliva A. Theoretical Insights on the Mechanism of the GTP Hydrolysis Catalyzed by the Elongation Factor Tu (EF-Tu). J Phys Chem B 2015; 120:89-101. [PMID: 26653849 DOI: 10.1021/acs.jpcb.5b10145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The purpose of this work is to have a better understanding of the mechanism of GTP hydrolysis catalyzed by the elongation factor Tu. Two main aspects are being discussed in the literature: the associative or dissociative character of the process and the nature of nucleophile activation. The calculations of the QM subsystem have been done by means of the M06-2X density functional and the split valence triple-ζ 6-311+G(d,p) basis set. The environmental effect has been introduced through the continuum SMD method. We have studied three models of increasing complexity in order to analyze the different factors that intervene in the catalytic action. The results obtained in this paper confirm that the protonated His84 plays a fundamental role in the catalytic mechanism, but we have also found that the crystallographic sodium ion has a notable effect in the catalysis. So, our work has permitted a new insight, complementary to those obtained with QM/MM calculations, into this very complex process.
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Affiliation(s)
- Carles Acosta-Silva
- Departament de Química, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
| | - Joan Bertran
- Departament de Química, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
| | - Vicenç Branchadell
- Departament de Química, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
| | - Antoni Oliva
- Departament de Química, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
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