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Khrenova MG, Grigorenko BL, Nemukhin AV. Molecular Modeling Reveals the Mechanism of Ran-RanGAP-Catalyzed Guanosine Triphosphate Hydrolysis without an Arginine Finger. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00582] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Maria G. Khrenova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
- Bach Institute of Biochemistry, Federal Research Centre “Fundamentals of Biotechnology”, Russian Academy of Sciences, Moscow 119071, Russia
| | - Bella L. Grigorenko
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow 19334, Russia
| | - Alexander V. Nemukhin
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow 19334, Russia
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2
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3
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Szeler K, Williams NH, Hengge AC, Kamerlin SCL. Modeling the Alkaline Hydrolysis of Diaryl Sulfate Diesters: A Mechanistic Study. J Org Chem 2020; 85:6489-6497. [PMID: 32309943 PMCID: PMC7304899 DOI: 10.1021/acs.joc.0c00441] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Indexed: 12/11/2022]
Abstract
Phosphate and sulfate esters have important roles in regulating cellular processes. However, while there has been substantial experimental and computational investigation of the mechanisms and the transition states involved in phosphate ester hydrolysis, there is far less work on sulfate ester hydrolysis. Here, we report a detailed computational study of the alkaline hydrolysis of diaryl sulfate diesters, using different DFT functionals as well as mixed implicit/explicit solvation with varying numbers of explicit water molecules. We consider the impact of the computational model on computed linear free-energy relationships (LFER) and the nature of the transition states (TS) involved. We obtain good qualitative agreement with experimental LFER data when using a pure implicit solvent model and excellent agreement with experimental kinetic isotope effects for all models used. Our calculations suggest that sulfate diester hydrolysis proceeds through loose transition states, with minimal bond formation to the nucleophile and bond cleavage to the leaving group already initiated. Comparison to prior work indicates that these TS are similar in nature to those for the alkaline hydrolysis of neutral arylsulfonate monoesters or charged phosphate diesters and fluorophosphates. Obtaining more detailed insights into the transition states involved assists in understanding the selectivity of enzymes that hydrolyze these reactions.
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Affiliation(s)
- Klaudia Szeler
- Department
of Chemistry − BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden
| | | | - Alvan C. Hengge
- Department
of Chemistry and Biochemistry, Utah State
University, Logan, Utah 84322-0300, United States
| | - Shina C. L. Kamerlin
- Department
of Chemistry − BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden
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4
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Calixto AR, Moreira C, Kamerlin SCL. Recent Advances in Understanding Biological GTP Hydrolysis through Molecular Simulation. ACS OMEGA 2020; 5:4380-4385. [PMID: 32175485 PMCID: PMC7066566 DOI: 10.1021/acsomega.0c00240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 02/18/2020] [Indexed: 05/04/2023]
Abstract
GTP hydrolysis is central to biology, being involved in regulating a wide range of cellular processes. However, the mechanisms by which GTPases hydrolyze this critical reaction remain controversial, with multiple mechanistic possibilities having been proposed based on analysis of experimental and computational data. In this mini-review, we discuss advances in our understanding of biological GTP hydrolysis based on recent computational studies and argue in favor of solvent-assisted hydrolysis as a conserved mechanism among GTPases. A concrete understanding of the fundamental mechanisms by which these enzymes facilitate GTP hydrolysis will have significant impact both for drug discovery efforts and for unraveling the role of oncogenic mutations.
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Affiliation(s)
- Ana Rita Calixto
- Department of Chemistry - BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden
| | - Cátia Moreira
- Department of Chemistry - BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden
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5
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Berta D, Buigues PJ, Badaoui M, Rosta E. Cations in motion: QM/MM studies of the dynamic and electrostatic roles of H + and Mg 2+ ions in enzyme reactions. Curr Opin Struct Biol 2020; 61:198-206. [PMID: 32065923 DOI: 10.1016/j.sbi.2020.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/04/2020] [Accepted: 01/06/2020] [Indexed: 12/17/2022]
Abstract
Here we discuss current trends in the simulations of enzymatic reactions focusing on phosphate catalysis. The mechanistic details of the proton transfers coupled to the phosphate cleavage is one of the key challenges in QM/MM calculations of these and other enzyme catalyzed reactions. The lack of experimental information offers both an opportunity for computations as well as often unresolved controversies. We discuss the example of small GTPases including the important human Ras protein. The high dimensionality and chemical complexity of these reactions demand carefully chosen computational techniques both in terms of the underlying quantum chemical theory and the sampling of the conformational ensemble. We also point out the important role of Mg2+ ions, and recent advances in their transient involvement in the catalytic mechanisms.
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Affiliation(s)
- Dénes Berta
- Department of Chemistry, King's College London, London, SE1 1DB, United Kingdom
| | - Pedro J Buigues
- Department of Chemistry, King's College London, London, SE1 1DB, United Kingdom
| | - Magd Badaoui
- Department of Chemistry, King's College London, London, SE1 1DB, United Kingdom
| | - Edina Rosta
- Department of Chemistry, King's College London, London, SE1 1DB, United Kingdom.
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6
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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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7
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van Bochove MA, Roos G, Fonseca Guerra C, Hamlin TA, Bickelhaupt FM. How Mg 2+ ions lower the S N2@P barrier in enzymatic triphosphate hydrolysis. Chem Commun (Camb) 2018. [PMID: 29537051 DOI: 10.1039/c8cc00700d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Our quantum chemical activation strain analyses demonstrate how Mg2+ lowers the barrier of the enzymatic triphosphate hydrolysis through two distinct mechanisms: (a) weakening of the leaving-group bond, thereby decreasing activation strain; and (b) transition state (TS) stabilization through enhanced electrophilicity of the triphosphate PPP substrate, thereby strengthening the interaction with the nucleophile.
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Affiliation(s)
- Marc A van Bochove
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling, Vrije Universiteit Amsterdam, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands.
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8
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Petrović D, Szeler K, Kamerlin SCL. Challenges and advances in the computational modeling of biological phosphate hydrolysis. Chem Commun (Camb) 2018; 54:3077-3089. [PMID: 29412205 DOI: 10.1039/c7cc09504j] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phosphate ester hydrolysis is fundamental to many life processes, and has been the topic of substantial experimental and computational research effort. However, even the simplest of phosphate esters can be hydrolyzed through multiple possible pathways that can be difficult to distinguish between, either experimentally, or computationally. Therefore, the mechanisms of both the enzymatic and non-enzymatic reactions have been historically controversial. In the present contribution, we highlight a number of technical issues involved in reliably modeling these computationally challenging reactions, as well as proposing potential solutions. We also showcase examples of our own work in this area, discussing both the non-enzymatic reaction in aqueous solution, as well as insights obtained from the computational modeling of organophosphate hydrolysis and catalytic promiscuity amongst enzymes that catalyze phosphoryl transfer.
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Affiliation(s)
- Dušan Petrović
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden.
| | - Klaudia Szeler
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden.
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9
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Barrozo A, Liao Q, Esguerra M, Marloie G, Florián J, Williams NH, Kamerlin SCL. Computer simulations of the catalytic mechanism of wild-type and mutant β-phosphoglucomutase. Org Biomol Chem 2018; 16:2060-2073. [DOI: 10.1039/c8ob00312b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
β-Phosphoglucomutase (β-PGM) has served as an important model system for understanding biological phosphoryl transfer.
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Affiliation(s)
- Alexandre Barrozo
- Science for Life Laboratory
- Department of Cell and Molecular Biology
- Uppsala University
- S-75124 Uppsala
- Sweden
| | - Qinghua Liao
- Science for Life Laboratory
- Department of Cell and Molecular Biology
- Uppsala University
- S-75124 Uppsala
- Sweden
| | - Mauricio Esguerra
- Science for Life Laboratory
- Department of Cell and Molecular Biology
- Uppsala University
- S-75124 Uppsala
- Sweden
| | - Gaël Marloie
- Science for Life Laboratory
- Department of Cell and Molecular Biology
- Uppsala University
- S-75124 Uppsala
- Sweden
| | - Jan Florián
- Department of Chemistry and Biochemistry
- Loyola University Chicago
- Chicago
- USA
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10
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Purg M, Kamerlin SCL. Empirical Valence Bond Simulations of Organophosphate Hydrolysis: Theory and Practice. Methods Enzymol 2018; 607:3-51. [DOI: 10.1016/bs.mie.2018.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Purg M, Elias M, Kamerlin SCL. Similar Active Sites and Mechanisms Do Not Lead to Cross-Promiscuity in Organophosphate Hydrolysis: Implications for Biotherapeutic Engineering. J Am Chem Soc 2017; 139:17533-17546. [PMID: 29113434 PMCID: PMC5724027 DOI: 10.1021/jacs.7b09384] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Indexed: 01/27/2023]
Abstract
Organophosphate hydrolases are proficient catalysts of the breakdown of neurotoxic organophosphates and have great potential as both biotherapeutics for treating acute organophosphate toxicity and as bioremediation agents. However, proficient organophosphatases such as serum paraoxonase 1 (PON1) and the organophosphate-hydrolyzing lactonase SsoPox are unable to hydrolyze bulkyorganophosphates with challenging leaving groups such as diisopropyl fluorophosphate (DFP) or venomous agent X, creating a major challenge for enzyme design. Curiously, despite their mutually exclusive substrate specificities, PON1 and diisopropyl fluorophosphatase (DFPase) have essentially identical active sites and tertiary structures. In the present work, we use empirical valence bond simulations to probe the catalytic mechanism of DFPase as well as temperature, pH, and mutational effects, demonstrating that DFPase and PON1 also likely utilize identical catalytic mechanisms to hydrolyze their respective substrates. However, detailed examination of both static structures and dynamical simulations demonstrates subtle but significant differences in the electrostatic properties and solvent penetration of the two active sites and, most critically, the role of residues that make no direct contact with either substrate in acting as "specificity switches" between the two enzymes. Specifically, we demonstrate that key residues that are structurally and functionally critical for the paraoxonase activity of PON1 prevent it from being able to hydrolyze DFP with its fluoride leaving group. These insights expand our understanding of the drivers of the evolution of divergent substrate specificity in enzymes with identical active sites and guide the future design of organophosphate hydrolases that hydrolyze compounds with challenging leaving groups.
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Affiliation(s)
- Miha Purg
- Science for Life
Laboratory, Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden
| | - Mikael Elias
- Department of Biochemistry, Molecular Biology and Biophysics &
Biotechnology Institute, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota 55108, United States
| | - Shina Caroline Lynn Kamerlin
- Science for Life
Laboratory, Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, S-751 24 Uppsala, Sweden
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12
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Pabis A, Williams NH, Kamerlin SCL. Simulating the reactions of substituted pyridinio-N-phosphonates with pyridine as a model for biological phosphoryl transfer. Org Biomol Chem 2017; 15:7308-7316. [DOI: 10.1039/c7ob01734k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This work provides a comprehensive model for non-enzymatic phosphoryl transfer, as a baseline for understanding biological phosphoryl transfer reactions.
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Affiliation(s)
- Anna Pabis
- Department of Cell and Molecular Biology
- Uppsala University
- S-751 24 Uppsala
- Sweden
| | | | - Shina C. L. Kamerlin
- Department of Cell and Molecular Biology
- Uppsala University
- S-751 24 Uppsala
- Sweden
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