1
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Varghese A, Waheed SO, Gorantla K, DiCastri I, LaRouche C, Kaski B, Fields GB, Karabencheva-Christova TG. Catalytic Mechanism of Collagen Hydrolysis by Zinc(II)-Dependent Matrix Metalloproteinase-1. J Phys Chem B 2023; 127:9697-9709. [PMID: 37931179 PMCID: PMC10659029 DOI: 10.1021/acs.jpcb.3c04293] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 11/08/2023]
Abstract
Human matrix metalloproteinase-1 (MMP-1) is a zinc(II)-dependent enzyme that catalyzes collagenolysis. Despite the availability of extensive experimental data, the mechanism of MMP-1-catalyzed collagenolysis remains poorly understood due to the lack of experimental structure of a catalytically productive enzyme-substrate complex of MMP-1. In this study, we apply molecular dynamics and combined quantum mechanics/molecular mechanics to reveal the reaction mechanism of MMP-1 based on a computationally modeled structure of the catalytically competent complex of MMP-1 that contains a large triple-helical peptide substrate. Our proposed mechanism involves the participation of an auxiliary (second) water molecule (wat2) in addition to the zinc(II)-coordinated water (wat1). The reaction initiates through a proton transfer to Glu219, followed by a nucleophilic attack by a zinc(II)-coordinated hydroxide anion nucleophile at the carbonyl carbon of the scissile bond, leading to the formation of a tetrahedral intermediate (IM2). The process continues with a hydrogen-bond rearrangement to facilitate proton transfer from wat2 to the amide nitrogen of the scissile bond and, finally, C-N bond cleavage. The calculations indicate that the rate-determining step is the water-mediated nucleophilic attack with an activation energy barrier of 22.3 kcal/mol. Furthermore, the calculations show that the hydrogen-bond rearrangement/proton-transfer step can proceed in a consecutive or concerted manner, depending on the conformation of the tetrahedral intermediate, with the consecutive mechanism being energetically preferable. Overall, the study reveals the crucial role of a second water molecule and the dynamics for effective MMP-1-catalyzed collagenolysis.
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Affiliation(s)
- Ann Varghese
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Sodiq O. Waheed
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Koteswararao Gorantla
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Isabella DiCastri
- Department
of Chemical Engineering, Michigan Technological
University, Houghton, Michigan 49931, United States
| | - Ciara LaRouche
- Department
of Chemical Engineering, Michigan Technological
University, Houghton, Michigan 49931, United States
| | - Brendan Kaski
- Department
of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Gregg B. Fields
- Department
of Chemistry and Biochemistry and I-HEALTH, Florida Atlantic University, Jupiter, Florida 33458, United States
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2
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Das S, Pattanayakanahalli Henjarappa K, Mahanta N. Enzymatic reconstitution of salicylate formation in promysalin biosynthesis. Bioorg Med Chem Lett 2023; 94:129440. [PMID: 37567320 DOI: 10.1016/j.bmcl.2023.129440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/02/2023] [Accepted: 08/08/2023] [Indexed: 08/13/2023]
Abstract
Promysalin is an amphipathic antibiotic isolated from Pseudomonas promysalinigenes (previously Pseudomonas putida RW10S1) which shows potent antibacterial activities against Gram-negative pathogens by inactivating succinate dehydrogenase. Based on the in-vivo studies, promysalin is hypothesized to be assembled from three building blocks: salicylic acid, proline, and myristic acid via a proposed but uncharacterized hybrid NRPS-PKS biosynthetic pathway. So far, no in-vitro biosynthetic studies have been reported for this promising antibiotic. Here, we report the first in-vitro reconstitution and biochemical characterization of two early enzymes on the pathway: PpgH, an isochorismate synthase (IS), and PpgG, an isochorismate pyruvate lyase (IPL) which are involved in the biosynthesis of salicylic acid, the polar fragment of promysalin. We also report a secondary chorismate mutase (CM) activity for PpgG. Based on our biochemical experiments, preliminary mechanistic proposals have been postulated for PpgH and PpgG. We believe this study will lay a strong foundation for elucidating the functions and mechanisms of other intriguing enzymes of the promysalin biosynthesis pathway, which may potentially unravel interesting enzyme chemistries and promote pathway engineering in the future.
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Affiliation(s)
- Simita Das
- Department of Chemistry, Indian Institute of Technology Dharwad, Karnataka 580011, India
| | | | - Nilkamal Mahanta
- Department of Chemistry, Indian Institute of Technology Dharwad, Karnataka 580011, India.
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3
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França TCC, Valle da Silva JA, Dos Santos MC, Cavalcante SFDA, Kuca K. Applications of the Near Attack Conformation (NAC) approach in the search for Acetylcholinesterase reactivators. Chem Biol Interact 2023; 382:110619. [PMID: 37406983 DOI: 10.1016/j.cbi.2023.110619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/25/2023] [Accepted: 06/30/2023] [Indexed: 07/07/2023]
Abstract
The Near Attack Conformation (NAC) approach states that the efficiency of an enzyme-catalyzed reaction depends on the prior attainment of optimal conditions for substrate atom organization and positioning for bond formation. These conditions are prerequisites for the transition state (TS) in which the involved atoms are within the van der Waals range of contact and positioned at an angle similar to that achieved after bond formation. The successful application of this approach to investigate the reactivation mechanism of acetylcholinesterase inhibited by nerve agents has contributed to a better understanding of this mechanism and demonstrated consistent corroboration with experimental data. In this article, we summarize the accomplishments achieved thus far and outline future perspectives.
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Affiliation(s)
- Tanos Celmar Costa França
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense, Military Institute of Engineering, Rio de Janeiro, Brazil; Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
| | - Jorge Alberto Valle da Silva
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Marcelo Carneiro Dos Santos
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Samir Frontino de Almeida Cavalcante
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic; Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, RJ, Brazil
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic
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4
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Hubrich F, Müller M, Andexer JN. Chorismate- and isochorismate converting enzymes: versatile catalysts acting on an important metabolic node. Chem Commun (Camb) 2021; 57:2441-2463. [PMID: 33605953 DOI: 10.1039/d0cc08078k] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chorismate and isochorismate represent an important branching point connecting primary and secondary metabolism in bacteria, fungi, archaea and plants. Chorismate- and isochorismate-converting enzymes are potential targets for new bioactive compounds, as well as valuable biocatalysts for the in vivo and in vitro synthesis of fine chemicals. The diversity of the products of chorismate- and isochorismate-converting enzymes is reflected in the enzymatic three-dimensional structures and molecular mechanisms. Due to the high reactivity of chorismate and its derivatives, these enzymes have evolved to be accurately tailored to their respective reaction; at the same time, many of them exhibit a fascinating flexibility regarding side reactions and acceptance of alternative substrates. Here, we give an overview of the different (sub)families of chorismate- and isochorismate-converting enzymes, their molecular mechanisms, and three-dimensional structures. In addition, we highlight important results of mutagenetic approaches that generate a broader understanding of the influence of distinct active site residues for product formation and the conversion of one subfamily into another. Based on this, we discuss to what extent the recent advances in the field might influence the general mechanistic understanding of chorismate- and isochorismate-converting enzymes. Recent discoveries of new chorismate-derived products and pathways, as well as biocatalytic conversions of non-physiological substrates, highlight how this vast field is expected to continue developing in the future.
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Affiliation(s)
- Florian Hubrich
- ETH Zurich, Institute of Microbiology, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
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5
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Tripathi RKP. A perspective review on fatty acid amide hydrolase (FAAH) inhibitors as potential therapeutic agents. Eur J Med Chem 2019; 188:111953. [PMID: 31945644 DOI: 10.1016/j.ejmech.2019.111953] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 02/06/2023]
Abstract
Fatty acid amide hydrolase (FAAH) is an important enzyme creditworthy of hydrolyzing endocannabinoids and related-amidated signalling lipids, discovery of which has pioneered novel arena of pharmacological canvasses to unwrap its curative potency in various diseased circumstances. It presents contemporary basis for understanding molecules regulating and mediating inflammatory reactions, pain, anxiety, depression, and neurodegeneration. FAAH inhibitors form vital approach for discovery of therapeutic agents that are concerned with local elevation of endocannabinoids under certain stimuli, debarring adverse/unwanted secondary effects from global activation of cannabinoid receptors by exogenous cannabimimetics. During past decades, several molecules with excellent potency developed through tailor-made approaches entered into clinical trials, but none could reach market. Hence, hunt for novel, non-toxic and selective FAAH inhibitors are on horizon. This review summarizes present perception on FAAH in conjunction with its structure, mechanism of catalysis and biological functions. It also foregrounds recent development of molecules belonging to diverse chemical classes as potential FAAH inhibitors bobbing up from in-depth chemical, mechanistic and computational studies published since 2015-November 2019, focusing on their potency. This review will assist readers to obtain rationale on FAAH as potential target for addressing various disease conditions, acquiring significant knowledge on recently established inhibitor scaffolds and their development potentials. New technologies including MD-MM simulations and 3D-QSAR studies allow mechanistic characterization of enzyme. Assessment of in-vitro and in-vivo efficacy of existing FAAH inhibitors will facilitate researchers to design novel ligands utilizing modern drug design methods. The discussions will also impose precaution in decision making process, quashing possibility of late stage failure.
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Affiliation(s)
- Rati Kailash Prasad Tripathi
- Department of Pharmaceutical Science, Sushruta School of Medical and Paramedical Sciences, Assam University (A Central University), Silchar, Assam, 788011, India; Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India.
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6
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Rinaldi S, Van der Kamp MW, Ranaghan KE, Mulholland AJ, Colombo G. Understanding Complex Mechanisms of Enzyme Reactivity: The Case of Limonene-1,2-Epoxide Hydrolases. ACS Catal 2018. [DOI: 10.1021/acscatal.8b00863] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Silvia Rinaldi
- Istituto di Chimica del Riconoscimento Molecolare, C.N.R., Via Mario Bianco 9, 20131 Milano, Italy
| | - Marc W. Van der Kamp
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
| | - Kara E. Ranaghan
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Adrian J. Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Giorgio Colombo
- Istituto di Chimica del Riconoscimento Molecolare, C.N.R., Via Mario Bianco 9, 20131 Milano, Italy
- Dipartimento di Chimica, Università degli Studi di Pavia, Via Taramelli 12, 27100 Pavia, Italy
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7
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Miranda-Rojas S, Fernández I, Kästner J, Toro-Labbé A, Mendizábal F. Unraveling the Nature of the Catalytic Power of Fluoroacetate Dehalogenase. ChemCatChem 2018. [DOI: 10.1002/cctc.201701517] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sebastián Miranda-Rojas
- Departamento de Ciencias Químicas; Facultad de Ciencias Exactas; Universidad Andres Bello; Av. República 275 Santiago Chile
| | - Israel Fernández
- Departamento de Química Orgánica I and Centro de Innovación en, Química Avanzada (ORFEO-CINQA); Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040- Madrid Spain
| | - Johannes Kästner
- Institut für Theoretische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Alejandro Toro-Labbé
- Laboratorio de Química Teórica Computacional; Facultad de Química; Pontifica Universidad Católica de Chile; Av. Vicuña Mackenna 4860, Macul Santiago Chile
| | - Fernando Mendizábal
- Departamento de Química; Facultad de Ciencias; Universidad de Chile; Las Palmeras 3425, Ñuñoa Santiago Chile
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8
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Pan LL, Song LF, Miao Y, Yang Y, Merz KM. Mechanism of Formation of the Nonstandard Product in the Prenyltransferase Reaction of the G115T Mutant of FtmPT1: A Case of Reaction Dynamics Calling the Shots? Biochemistry 2017; 56:2995-3007. [PMID: 28570807 DOI: 10.1021/acs.biochem.7b00248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
FtmPT1 is a fungal indole prenyltransferase that affords Tryprostatin B from Brevianamide F and dimethylallyl pyrophosphate; however, when a single residue in the active site is mutated (Gly115Thr), a novel five-membered ring compound is obtained as the major product with Tryprostatin B as the minor product. Herein, we describe detailed studies of the catalysis of the Gly115Thr mutant of FtmPT1 with a focus on the observed regioselectivity of the reaction. We employ one- and two-dimensional potential of mean force simulations to explore the catalytic mechanism, along with molecular dynamics simulations exploring the reaction dynamics of the prenyl transfer reaction. Single-point electronic structure calculations were also used to explore the performance of the self-consistent charge density functional tight-binding method to model specific reaction steps. Importantly, we observe that the two reaction pathways have comparable activation parameters and propose that the origin of the novel product is predicated, at least in part, on the topology of the potential energy surface as revealed by reaction dynamics studies.
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Affiliation(s)
- Li-Li Pan
- Department of Chemistry and Department of Biochemistry and Molecular Biology, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Lin Frank Song
- Department of Chemistry and Department of Biochemistry and Molecular Biology, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Yipu Miao
- Department of Chemistry and Department of Biochemistry and Molecular Biology, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Yue Yang
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory , 7000 East Avenue, Livermore, California 94550, United States
| | - Kenneth M Merz
- Department of Chemistry and Department of Biochemistry and Molecular Biology, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824, United States.,Institute for Cyber Enabled Research, Michigan State University , 567 Wilson Road, Room 1440, East Lansing, Michigan 48824, United States
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9
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Burschowsky D, Krengel U, Uggerud E, Balcells D. Quantum chemical modeling of the reaction path of chorismate mutase based on the experimental substrate/product complex. FEBS Open Bio 2017; 7:789-797. [PMID: 28593134 PMCID: PMC5458464 DOI: 10.1002/2211-5463.12224] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 02/26/2017] [Accepted: 03/22/2017] [Indexed: 11/10/2022] Open
Abstract
Chorismate mutase is a well-known model enzyme, catalyzing the Claisen rearrangement of chorismate to prephenate. Recent high-resolution crystal structures along the reaction coordinate of this enzyme enabled computational analyses at unprecedented detail. Using quantum chemical simulations, we investigated how the catalytic reaction mechanism is affected by electrostatic and hydrogen-bond interactions. Our calculations showed that the transition state (TS) was mainly stabilized electrostatically, with Arg90 playing the leading role. The effect was augmented by selective hydrogen-bond formation to the TS in the wild-type enzyme, facilitated by a small-scale local induced fit. We further identified a previously underappreciated water molecule, which separates the negative charges during the reaction. The analysis includes the wild-type enzyme and a non-natural enzyme variant, where the catalytic arginine was replaced with an isosteric citrulline residue.
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Affiliation(s)
- Daniel Burschowsky
- Department of Chemistry University of Oslo Norway.,Present address: Leicester Institute of Structural and Chemical Biology University of Leicester Leicester UK
| | - Ute Krengel
- Department of Chemistry University of Oslo Norway
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10
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Tuszynski JA, Winter P, White D, Tseng CY, Sahu KK, Gentile F, Spasevska I, Omar SI, Nayebi N, Churchill CD, Klobukowski M, El-Magd RMA. Mathematical and computational modeling in biology at multiple scales. Theor Biol Med Model 2014; 11:52. [PMID: 25542608 PMCID: PMC4396153 DOI: 10.1186/1742-4682-11-52] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 11/25/2014] [Indexed: 01/08/2023] Open
Abstract
A variety of topics are reviewed in the area of mathematical and computational modeling in biology, covering the range of scales from populations of organisms to electrons in atoms. The use of maximum entropy as an inference tool in the fields of biology and drug discovery is discussed. Mathematical and computational methods and models in the areas of epidemiology, cell physiology and cancer are surveyed. The technique of molecular dynamics is covered, with special attention to force fields for protein simulations and methods for the calculation of solvation free energies. The utility of quantum mechanical methods in biophysical and biochemical modeling is explored. The field of computational enzymology is examined.
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Affiliation(s)
- Jack A Tuszynski
- Department of Physics and Department of Oncology, University of Alberta, Edmonton, Canada.
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11
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Sadiq SK, Coveney PV. Computing the Role of Near Attack Conformations in an Enzyme-Catalyzed Nucleophilic Bimolecular Reaction. J Chem Theory Comput 2014; 11:316-24. [DOI: 10.1021/ct5008845] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- S. Kashif Sadiq
- Infection
Biology Unit, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), C/Doctor Aiguader 88, 08003 Barcelona, Spain
| | - Peter V. Coveney
- Centre
for Computational Science, Department of Chemistry, University College London, London WC1H 0AJ, United Kingdom
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12
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Wijma HJ, Marrink SJ, Janssen DB. Computationally efficient and accurate enantioselectivity modeling by clusters of molecular dynamics simulations. J Chem Inf Model 2014; 54:2079-92. [PMID: 24916632 DOI: 10.1021/ci500126x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Computational approaches could decrease the need for the laborious high-throughput experimental screening that is often required to improve enzymes by mutagenesis. Here, we report that using multiple short molecular dynamics (MD) simulations makes it possible to accurately model enantioselectivity for large numbers of enzyme-substrate combinations at low computational costs. We chose four different haloalkane dehalogenases as model systems because of the availability of a large set of experimental data on the enantioselective conversion of 45 different substrates. To model the enantioselectivity, we quantified the frequency of occurrence of catalytically productive conformations (near attack conformations) for pairs of enantiomers during MD simulations. We found that the angle of nucleophilic attack that leads to carbon-halogen bond cleavage was a critical variable that limited the occurrence of productive conformations; enantiomers for which this angle reached values close to 180° were preferentially converted. A cluster of 20-40 very short (10 ps) MD simulations allowed adequate conformational sampling and resulted in much better agreement to experimental enantioselectivities than single long MD simulations (22 ns), while the computational costs were 50-100 fold lower. With single long MD simulations, the dynamics of enzyme-substrate complexes remained confined to a conformational subspace that rarely changed significantly, whereas with multiple short MD simulations a larger diversity of conformations of enzyme-substrate complexes was observed.
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Affiliation(s)
- Hein J Wijma
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
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13
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Christensen AS, Steinmann C, Fedorov DG, Jensen JH. Hybrid RHF/MP2 geometry optimizations with the effective fragment molecular orbital method. PLoS One 2014; 9:e88800. [PMID: 24558430 PMCID: PMC3928295 DOI: 10.1371/journal.pone.0088800] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 01/15/2014] [Indexed: 11/18/2022] Open
Abstract
The frozen domain effective fragment molecular orbital method is extended to allow for the treatment of a single fragment at the MP2 level of theory. The approach is applied to the conversion of chorismate to prephenate by Chorismate Mutase, where the substrate is treated at the MP2 level of theory while the rest of the system is treated at the RHF level. MP2 geometry optimization is found to lower the barrier by up to 3.5 kcal/mol compared to RHF optimzations and ONIOM energy refinement and leads to a smoother convergence with respect to the basis set for the reaction profile. For double zeta basis sets the increase in CPU time relative to RHF is roughly a factor of two.
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Affiliation(s)
| | - Casper Steinmann
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Dmitri G. Fedorov
- Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Jan H. Jensen
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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14
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Choutko A, Eichenberger AP, van Gunsteren WF, Dolenc J. Exploration of swapping enzymatic function between two proteins: a simulation study of chorismate mutase and isochorismate pyruvate lyase. Protein Sci 2013; 22:809-22. [PMID: 23595942 DOI: 10.1002/pro.2264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 03/31/2013] [Indexed: 01/09/2023]
Abstract
The enzyme chorismate mutase EcCM from Escherichia coli catalyzes one of the few pericyclic reactions in biology, the transformation of chorismate to prephenate. The isochorismate pyruvate lyase PchB from Pseudomonas aeroginosa catalyzes another pericyclic reaction, the isochorismate to salicylate transformation. Interestingly, PchB possesses weak chorismate mutase activity as well thus being able to catalyze two distinct pericyclic reactions in a single active site. EcCM and PchB possess very similar folds, despite their low sequence identity. Using molecular dynamics simulations of four combinations of the two enzymes (EcCM and PchB) with the two substrates (chorismate and isochorismate) we show that the electrostatic field due to EcCM at atoms of chorismate favors the chorismate to prephenate transition and that, analogously, the electrostatic field due to PchB at atoms of isochorismate favors the isochorismate to salicylate transition. The largest differences between EcCM and PchB in electrostatic field strengths at atoms of the substrates are found to be due to residue side chains at distances between 0.6 and 0.8 nm from particular substrate atoms. Both enzymes tend to bring their non-native substrate in the same conformation as their native substrate. EcCM and to a lower extent PchB fail in influencing the forces on and conformations of the substrate such as to favor the other chemical reaction (isochorismate pyruvate lyase activity for EcCM and chorismate mutase activity for PchB). These observations might explain the difficulty of engineering isochorismate pyruvate lyase activity in EcCM by solely mutating active site residues.
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Affiliation(s)
- Alexandra Choutko
- Physical Chemistry, Swiss Federal Institute of Technology, ETH, Zürich, Switzerland
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15
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van der Kamp MW, Mulholland AJ. Combined quantum mechanics/molecular mechanics (QM/MM) methods in computational enzymology. Biochemistry 2013; 52:2708-28. [PMID: 23557014 DOI: 10.1021/bi400215w] [Citation(s) in RCA: 394] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Computational enzymology is a rapidly maturing field that is increasingly integral to understanding mechanisms of enzyme-catalyzed reactions and their practical applications. Combined quantum mechanics/molecular mechanics (QM/MM) methods are important in this field. By treating the reacting species with a quantum mechanical method (i.e., a method that calculates the electronic structure of the active site) and including the enzyme environment with simpler molecular mechanical methods, enzyme reactions can be modeled. Here, we review QM/MM methods and their application to enzyme-catalyzed reactions to investigate fundamental and practical problems in enzymology. A range of QM/MM methods is available, from cheaper and more approximate methods, which can be used for molecular dynamics simulations, to highly accurate electronic structure methods. We discuss how modeling of reactions using such methods can provide detailed insight into enzyme mechanisms and illustrate this by reviewing some recent applications. We outline some practical considerations for such simulations. Further, we highlight applications that show how QM/MM methods can contribute to the practical development and application of enzymology, e.g., in the interpretation and prediction of the effects of mutagenesis and in drug and catalyst design.
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Affiliation(s)
- Marc W van der Kamp
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
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16
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Meier K, Choutko A, Dolenc J, Eichenberger AP, Riniker S, van Gunsteren WF. Multi-Resolution Simulation of Biomolecular Systems: A Review of Methodological Issues. Angew Chem Int Ed Engl 2013; 52:2820-34. [DOI: 10.1002/anie.201205408] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 09/12/2012] [Indexed: 01/01/2023]
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17
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Meier K, Choutko A, Dolenc J, Eichenberger AP, Riniker S, van Gunsteren WF. Biomolekulare Simulationen mit mehreren Auflösungsniveaus: ein Überblick über methodische Aspekte. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201205408] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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18
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Abstract
Techniques for modelling enzyme-catalyzed reaction mechanisms are making increasingly important contributions to biochemistry. They can address fundamental questions in enzyme catalysis and have the potential to contribute to practical applications such as drug development.
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19
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Near attack conformers dominate β-phosphoglucomutase complexes where geometry and charge distribution reflect those of substrate. Proc Natl Acad Sci U S A 2012; 109:6910-5. [PMID: 22505741 DOI: 10.1073/pnas.1116855109] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Experimental observations of fluoromagnesate and fluoroaluminate complexes of β-phosphoglucomutase (β-PGM) have demonstrated the importance of charge balance in transition-state stabilization for phosphoryl transfer enzymes. Here, direct observations of ground-state analog complexes of β-PGM involving trifluoroberyllate establish that when the geometry and charge distribution closely match those of the substrate, the distribution of conformers in solution and in the crystal predominantly places the reacting centers in van der Waals proximity. Importantly, two variants are found, both of which satisfy the criteria for near attack conformers. In one variant, the aspartate general base for the reaction is remote from the nucleophile. The nucleophile remains protonated and forms a nonproductive hydrogen bond to the phosphate surrogate. In the other variant, the general base forms a hydrogen bond to the nucleophile that is now correctly orientated for the chemical transfer step. By contrast, in the absence of substrate, the solvent surrounding the phosphate surrogate is arranged to disfavor nucleophilic attack by water. Taken together, the trifluoroberyllate complexes of β-PGM provide a picture of how the enzyme is able to organize itself for the chemical step in catalysis through the population of intermediates that respond to increasing proximity of the nucleophile. These experimental observations show how the enzyme is capable of stabilizing the reaction pathway toward the transition state and also of minimizing unproductive catalysis of aspartyl phosphate hydrolysis.
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20
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Lonsdale R, Hoyle S, Grey DT, Ridder L, Mulholland AJ. Determinants of reactivity and selectivity in soluble epoxide hydrolase from quantum mechanics/molecular mechanics modeling. Biochemistry 2012; 51:1774-86. [PMID: 22280021 PMCID: PMC3290109 DOI: 10.1021/bi201722j] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Soluble epoxide hydrolase (sEH) is an enzyme involved in drug metabolism that catalyzes the hydrolysis of epoxides to form their corresponding diols. sEH has a broad substrate range and shows high regio- and enantioselectivity for nucleophilic ring opening by Asp333. Epoxide hydrolases therefore have potential synthetic applications. We have used combined quantum mechanics/molecular mechanics (QM/MM) umbrella sampling molecular dynamics (MD) simulations (at the AM1/CHARMM22 level) and high-level ab initio (SCS-MP2) QM/MM calculations to analyze the reactions, and determinants of selectivity, for two substrates: trans-stilbene oxide (t-SO) and trans-diphenylpropene oxide (t-DPPO). The calculated free energy barriers from the QM/MM (AM1/CHARMM22) umbrella sampling MD simulations show a lower barrier for phenyl attack in t-DPPO, compared with that for benzylic attack, in agreement with experiment. Activation barriers in agreement with experimental rate constants are obtained only with the highest level of QM theory (SCS-MP2) used. Our results show that the selectivity of the ring-opening reaction is influenced by several factors, including proximity to the nucleophile, electronic stabilization of the transition state, and hydrogen bonding to two active site tyrosine residues. The protonation state of His523 during nucleophilic attack has also been investigated, and our results show that the protonated form is most consistent with experimental findings. The work presented here illustrates how determinants of selectivity can be identified from QM/MM simulations. These insights may also provide useful information for the design of novel catalysts for use in the synthesis of enantiopure compounds.
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Affiliation(s)
- Richard Lonsdale
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
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21
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Abstract
One of the fundamental questions of enzymology is how catalytic power is derived. This review focuses on recent developments in the structure--function relationships of chorismate-utilizing enzymes involved in siderophore biosynthesis to provide insight into the biocatalysis of pericyclic reactions. Specifically, salicylate synthesis by the two-enzyme pathway in Pseudomonas aeruginosa is examined. The isochorismate-pyruvate lyase is discussed in the context of its homologues, the chorismate mutases, and the isochorismate synthase is compared to its homologues in the MST family (menaquinone, siderophore, or tryptophan biosynthesis) of enzymes. The tentative conclusion is that the activities observed cannot be reconciled by inspection of the active site participants alone. Instead, individual activities must arise from unique dynamic properties of each enzyme that are tuned to promote specific chemistries.
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Affiliation(s)
- Audrey L Lamb
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, United States.
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22
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Olucha J, Ouellette AN, Luo Q, Lamb AL. pH Dependence of catalysis by Pseudomonas aeruginosa isochorismate-pyruvate lyase: implications for transition state stabilization and the role of lysine 42. Biochemistry 2011; 50:7198-207. [PMID: 21751784 DOI: 10.1021/bi200599j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An isochorismate-pyruvate lyase with adventitious chorismate mutase activity from Pseudomonas aerugionsa (PchB) achieves catalysis of both pericyclic reactions in part by the stabilization of reactive conformations and in part by electrostatic transition-state stabilization. When the active site loop Lys42 is mutated to histidine, the enzyme develops a pH dependence corresponding to a loss of catalytic power upon deprotonation of the histidine. Structural data indicate that the change is not due to changes in active site architecture, but due to the difference in charge at this key site. With loss of the positive charge on the K42H side chain at high pH, the enzyme retains lyase activity at ∼100-fold lowered catalytic efficiency but loses detectable mutase activity. We propose that both substrate organization and electrostatic transition state stabilization contribute to catalysis. However, the dominant reaction path for catalysis is dependent on reaction conditions, which influence the electrostatic properties of the enzyme active site amino acid side chains.
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Affiliation(s)
- Jose Olucha
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
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23
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Kamerlin SCL, Vicatos S, Dryga A, Warshel A. Coarse-grained (multiscale) simulations in studies of biophysical and chemical systems. Annu Rev Phys Chem 2011; 62:41-64. [PMID: 21034218 DOI: 10.1146/annurev-physchem-032210-103335] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent years have witnessed an explosion in computational power, leading to attempts to model ever more complex systems. Nevertheless, there remain cases for which the use of brute-force computer simulations is clearly not the solution. In such cases, great benefit can be obtained from the use of physically sound simplifications. The introduction of such coarse graining can be traced back to the early usage of a simplified model in studies of proteins. Since then, the field has progressed tremendously. In this review, we cover both key developments in the field and potential future directions. Additionally, particular emphasis is given to two general approaches, namely the renormalization and reference potential approaches, which allow one to move back and forth between the coarse-grained (CG) and full models, as these approaches provide the foundation for CG modeling of complex systems.
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Affiliation(s)
- Shina C L Kamerlin
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
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24
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Claeyssens F, Ranaghan KE, Lawan N, Macrae SJ, Manby FR, Harvey JN, Mulholland AJ. Analysis of chorismate mutase catalysis by QM/MM modelling of enzyme-catalysed and uncatalysed reactions. Org Biomol Chem 2011; 9:1578-90. [PMID: 21243152 DOI: 10.1039/c0ob00691b] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Chorismate mutase is at the centre of current controversy about fundamental features of biological catalysts. Some recent studies have proposed that catalysis in this enzyme does not involve transition state (TS) stabilization but instead is due largely to the formation of a reactive conformation of the substrate. To understand the origins of catalysis, it is necessary to compare equivalent reactions in different environments. The pericyclic conversion of chorismate to prephenate catalysed by chorismate mutase also occurs (much more slowly) in aqueous solution. In this study we analyse the origins of catalysis by comparison of multiple quantum mechanics/molecular mechanics (QM/MM) reaction pathways at a reliable, well tested level of theory (B3LYP/6-31G(d)/CHARMM27) for the reaction (i) in Bacillus subtilis chorismate mutase (BsCM) and (ii) in aqueous solvent. The average calculated reaction (potential energy) barriers are 11.3 kcal mol(-1) in the enzyme and 17.4 kcal mol(-1) in water, both of which are in good agreement with experiment. Comparison of the two sets of reaction pathways shows that the reaction follows a slightly different reaction pathway in the enzyme than in it does in solution, because of a destabilization, or strain, of the substrate in the enzyme. The substrate strain energy within the enzyme remains constant throughout the reaction. There is no unique reactive conformation of the substrate common to both environments, and the transition state structures are also different in the enzyme and in water. Analysis of the barrier heights in each environment shows a clear correlation between TS stabilization and the barrier height. The average differential TS stabilization is 7.3 kcal mol(-1) in the enzyme. This is significantly higher than the small amount of TS stabilization in water (on average only 1.0 kcal mol(-1) relative to the substrate). The TS is stabilized mainly by electrostatic interactions with active site residues in the enzyme, with Arg90, Arg7 and Glu78 generally the most important. Conformational effects (e.g. strain of the substrate in the enzyme) do not contribute significantly to the lower barrier observed in the enzyme. The results show that catalysis is mainly due to better TS stabilization by the enzyme.
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Affiliation(s)
- Frederik Claeyssens
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, UK BS8 1TS
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25
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McGeagh JD, Ranaghan KE, Mulholland AJ. Protein dynamics and enzyme catalysis: insights from simulations. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1814:1077-92. [PMID: 21167324 DOI: 10.1016/j.bbapap.2010.12.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 11/25/2010] [Accepted: 12/03/2010] [Indexed: 10/18/2022]
Abstract
The role of protein dynamics in enzyme catalysis is one of the most active and controversial areas in enzymology today. Some researchers claim that protein dynamics are at the heart of enzyme catalytic efficiency, while others state that dynamics make no significant contribution to catalysis. What is the biochemist - or student - to make of the ferocious arguments in this area? Protein dynamics are complex and fascinating, as molecular dynamics simulations and experiments have shown. The essential question is: do these complex motions have functional significance? In particular, how do they affect or relate to chemical reactions within enzymes, and how are chemical and conformational changes coupled together? Biomolecular simulations can analyse enzyme reactions and dynamics in atomic detail, beyond that achievable in experiments: accurate atomistic modelling has an essential part to play in clarifying these issues. This article is part of a Special Issue entitled: Protein Dynamics: Experimental and Computational Approaches.
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Affiliation(s)
- John D McGeagh
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Cantock's Close, BS8 1TS, United Kingdom
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26
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Kamerlin SCL, Mavri J, Warshel A. Examining the case for the effect of barrier compression on tunneling, vibrationally enhanced catalysis, catalytic entropy and related issues. FEBS Lett 2010; 584:2759-66. [PMID: 20433839 DOI: 10.1016/j.febslet.2010.04.062] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 04/21/2010] [Accepted: 04/22/2010] [Indexed: 10/19/2022]
Abstract
The idea that tunneling is enhanced by the compression of the donor-acceptor distance has attracted significant interest. In particular, recent studies argued that this proposal is consistent with pressure effects on enzymatic reactions, and that the observed pressure effects support the idea of vibrationally enhanced catalysis. However, a careful analysis of the current works reveals serious inconsistencies in the evidence presented to support these hypotheses. Apparently, tunneling decreases upon compression, and external pressure does not lead to the applicable compression of the free energy surface. Additionally, pressure experiments do not provide actual evidence for vibrationally enhanced catalysis. Finally, the temperature dependence of the entropy change in hydride transfer reactions is shown to reflect simple electrostatic effects.
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27
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Ishida T. Effects of Point Mutation on Enzymatic Activity: Correlation between Protein Electronic Structure and Motion in Chorismate Mutase Reaction. J Am Chem Soc 2010; 132:7104-18. [DOI: 10.1021/ja100744h] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Toyokazu Ishida
- Research Institute for Computational Sciences (RICS), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba 305-8568, Japan
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28
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Ranaghan KE, Mulholland AJ. Investigations of enzyme-catalysed reactions with combined quantum mechanics/molecular mechanics (QM/MM) methods. INT REV PHYS CHEM 2010. [DOI: 10.1080/01442350903495417] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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29
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30
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Luo Q, Olucha J, Lamb AL. Structure-function analyses of isochorismate-pyruvate lyase from Pseudomonas aeruginosa suggest differing catalytic mechanisms for the two pericyclic reactions of this bifunctional enzyme. Biochemistry 2009; 48:5239-45. [PMID: 19432488 DOI: 10.1021/bi900456e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The isochorismate-pyruvate lyase from Pseudomonas aeruginosa (PchB) catalyzes two pericyclic reactions in a single active site. PchB physiologically produces salicylate and pyruvate from isochorismate for ultimate incorporation of the salicylate into the siderophore pyochelin. PchB also produces prephenate from chorismate, most likely due to structural homology to the Escherchia coli chorismate mutase. The molecular basis of catalysis among enzymatic pericyclic reactions is a matter of debate, one view holding that catalysis may be derived from electrostatic transition state stabilization and the opposing view that catalysis is derived from the generation of a reactive substrate conformation. Mutant forms of PchB were generated by site-directed mutagenesis at the site (K42) hypothesized to be key for electrostatic transition state stabilization (K42A, K42Q, K42E, and K42H). The loop containing K42 is mobile, and a mutant to slow loop dynamics was also designed (A43P). Finally, a previously characterized mutation (I87T) was also produced. Circular dichroism was used to assess the overall effect on secondary structure as a result of the mutations, and X-ray crystallographic structures are reported for K42A with salicylate and pyruvate bound and for apo-I87T. The data illustrate that the active site architecture is maintained in K42A-PchB, which indicates that differences in activity are not caused by secondary structural changes or by differences in active site loop conformation but rather by the chemical nature of this key residue. In contrast, the I87T structure demonstrates considerable mobility, suggesting that loop dynamics and conformational plasticity may be important for efficient catalysis. Finally, the mutational effects on k(cat) provide evidence that the two activities of PchB are not covariant and that a single hypothesis may not provide a sufficient explanation for catalysis.
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Affiliation(s)
- Qianyi Luo
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
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31
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Abstract
Combined quantum-mechanics/molecular-mechanics (QM/MM) approaches have become the method of choice for modeling reactions in biomolecular systems. Quantum-mechanical (QM) methods are required for describing chemical reactions and other electronic processes, such as charge transfer or electronic excitation. However, QM methods are restricted to systems of up to a few hundred atoms. However, the size and conformational complexity of biopolymers calls for methods capable of treating up to several 100,000 atoms and allowing for simulations over time scales of tens of nanoseconds. This is achieved by highly efficient, force-field-based molecular mechanics (MM) methods. Thus to model large biomolecules the logical approach is to combine the two techniques and to use a QM method for the chemically active region (e.g., substrates and co-factors in an enzymatic reaction) and an MM treatment for the surroundings (e.g., protein and solvent). The resulting schemes are commonly referred to as combined or hybrid QM/MM methods. They enable the modeling of reactive biomolecular systems at a reasonable computational effort while providing the necessary accuracy.
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Affiliation(s)
- Hans Martin Senn
- Department of Chemistry, WestCHEM and University of Glasgow, Glasgow G12 8QQ, UK.
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32
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33
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van der Kamp MW, Shaw KE, Woods CJ, Mulholland AJ. Biomolecular simulation and modelling: status, progress and prospects. J R Soc Interface 2008; 5 Suppl 3:S173-90. [PMID: 18611844 PMCID: PMC2706107 DOI: 10.1098/rsif.2008.0105.focus] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 06/05/2008] [Accepted: 06/06/2008] [Indexed: 11/12/2022] Open
Abstract
Molecular simulation is increasingly demonstrating its practical value in the investigation of biological systems. Computational modelling of biomolecular systems is an exciting and rapidly developing area, which is expanding significantly in scope. A range of simulation methods has been developed that can be applied to study a wide variety of problems in structural biology and at the interfaces between physics, chemistry and biology. Here, we give an overview of methods and some recent developments in atomistic biomolecular simulation. Some recent applications and theoretical developments are highlighted.
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Affiliation(s)
| | | | | | - Adrian J. Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of BristolBristol BS8 1TS, UK
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34
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Abstract
Simulations and modelling [e.g. with combined QM/MM (quantum mechanics/molecular mechanics) methods] are increasingly important in investigations of enzyme-catalysed reaction mechanisms. Calculations offer the potential of uniquely detailed, atomic-level insight into the fundamental processes of biological catalysis. Highly accurate methods promise quantitative comparison with experiments, and reliable predictions of mechanisms, revolutionizing enzymology.
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35
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van der Kamp MW, Mulholland AJ. Computational enzymology: insight into biological catalysts from modelling. Nat Prod Rep 2008; 25:1001-14. [DOI: 10.1039/b600517a] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Kovalev NA, Medvedeva DA, Zenkova MA, Vlassov VV. Cleavage of RNA by an amphiphilic compound lacking traditional catalytic groups. Bioorg Chem 2007; 36:33-45. [PMID: 18061645 DOI: 10.1016/j.bioorg.2007.10.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 10/02/2007] [Accepted: 10/05/2007] [Indexed: 12/23/2022]
Abstract
Recently, in experiments with combinatorial libraries of amphiphilic compounds lacking groups, known as catalysts of transesterification reaction, we discovered novel RNA-cleaving compounds [N. Kovalev, E. Burakova, V. Silnikov, M. Zenkova, V. Vlassov, Bioorg. Chem. 34 (2006) 274-286]. In the present study, we investigate cleavage of RNA by the most active representative of these libraries, compound named Dp12. Sequence-specificity of RNA cleavage and influence of reaction conditions on cleavage rate suggested that Dp12 enormously accelerates spontaneous RNA cleavage. Light scattering experiments revealed that the RNA cleavage proceeds within multiplexes formed by assembles of RNA and Dp12 molecules, at Dp12 concentration far below critical concentration of micelle formation. Under these conditions, Dp12 is presented in the solution as individual molecules, but addition of RNA to this solution triggers formation of the multiplexes. The obtained data suggest a possible mechanism of RNA cleavage, which includes interaction of the compound with RNA sugar-phosphate backbone resulting in changing of ribose conformation. This leads to juxtaposition of the 2'-hydroxyl group and internucleotide phosphorus atom at a distance needed for the transesterification to occur.
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Affiliation(s)
- N A Kovalev
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, 8 Lavrentiev Avenue, 630090 Novosibirsk, Russian Federation
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37
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Olsson MHM, Parson WW, Warshel A. Dynamical contributions to enzyme catalysis: critical tests of a popular hypothesis. Chem Rev 2007; 106:1737-56. [PMID: 16683752 DOI: 10.1021/cr040427e] [Citation(s) in RCA: 254] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mats H M Olsson
- Department of Chemistry, University of Southern California, 3620 McClintock Avenue, Los Angeles, California 90089-1062, USA.
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38
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Warshel A, Sharma PK, Kato M, Xiang Y, Liu H, Olsson MHM. Electrostatic basis for enzyme catalysis. Chem Rev 2007; 106:3210-35. [PMID: 16895325 DOI: 10.1021/cr0503106] [Citation(s) in RCA: 966] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Arieh Warshel
- Department of Chemistry, University of Southern California, SGM Building 418, 3620 McClintock Avenue, Los Angeles, California 90089-1062, USA.
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39
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Min D, Xue S, Li H, Yang W. 'In-line attack' conformational effect plays a modest role in an enzyme-catalyzed RNA cleavage: a free energy simulation study. Nucleic Acids Res 2007; 35:4001-6. [PMID: 17553832 PMCID: PMC1919504 DOI: 10.1093/nar/gkm394] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 04/10/2007] [Accepted: 05/01/2007] [Indexed: 12/19/2022] Open
Abstract
Since the proposal of 'in-line attack' conformation as a possibly important intermediate in RNA cleavage, its structure has been captured in various protein and RNA enzymes; these structures strengthen the belief that this conformation plays an essential role in the catalysis of RNA cleavage. As generally discussed, this intermediate structure can be involved in energy barrier reduction in two possible ways, e.g. through either conformational effect or electrostatic effect. In order to quantitatively elucidate the contribution of conformational effect in this type of enzyme catalysis, free energy simulations were performed on the RNA structures both in a splicing endonuclease complex and in the aqueous solution. Our free energy simulation results revealed that the 'in-line attack' conformational effect plays a modest role in facilitating the reaction rate enhancement (approximately 12-fold) compared with the overall 10(12)-fold rate increase. The close agreement between the present computational estimation and an experimental measurement on the spontaneous RNA cleavage in an in vitro evolved ATP aptamer motives us to realize that the conformation distribution of an enzyme substrate prior to rather than after its binding determines the upper bound of the rate enhancement ability through the conformational strategy.
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Affiliation(s)
- Donghong Min
- School of Computational Science, Institute of Molecular Biophysics and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306
| | - Song Xue
- School of Computational Science, Institute of Molecular Biophysics and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306
| | - Hong Li
- School of Computational Science, Institute of Molecular Biophysics and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306
| | - Wei Yang
- School of Computational Science, Institute of Molecular Biophysics and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306
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40
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Masgrau L, Ranaghan KE, Scrutton NS, Mulholland AJ, Sutcliffe MJ. Tunneling and Classical Paths for Proton Transfer in an Enzyme Reaction Dominated by Tunneling: Oxidation of Tryptamine by Aromatic Amine Dehydrogenase. J Phys Chem B 2007; 111:3032-47. [PMID: 17388439 DOI: 10.1021/jp067898k] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proton tunneling dominates the oxidative deamination of tryptamine catalyzed by the enzyme aromatic amine dehydrogenase. For reaction with the fast substrate tryptamine, a H/D kinetic isotope effect (KIE) of 55 +/- 6 has been reported-one of the largest observed in an enzyme reaction. We present here a computational analysis of this proton-transfer reaction, applying combined quantum mechanics/molecular mechanics (QM/MM) methods (PM3-SRP//PM3/CHARMM22). In particular, we extend our previous computational study (Masgrau et al. Science 2006, 312, 237) by using improved energy corrections, high-level QM/MM methods, and an ensemble of paths to estimate the tunneling contributions. We have carried out QM/MM molecular dynamics simulations and variational transition state theory calculations with small-curvature tunneling corrections. The results provide detailed insight into the processes involved in the reaction. Transfer to the O2 oxygen of the catalytic base, Asp128beta, is found to be the favored reaction both thermodynamically and kinetically, even though O1 is closer in the reactant complex. Comparison of quantum and classical models of proton transfer allows estimation of the contribution of hydrogen tunneling in lowering the barrier to reaction in the enzyme. A reduction of the activation free energy due to tunneling of 3.1 kcal mol-1 is found, which represents a rate enhancement due to tunneling by 2 orders of magnitude. The calculated KIE of 30 is significantly elevated over the semiclassical limit, in agreement with the experimental observations; a semiclassical value of 6 is obtained when tunneling is omitted. A polarization of the C-H bond to be broken is observed due to the close proximity of the catalytic aspartate and the (formally) positively charged imine nitrogen. A comparison is also made with the related quinoprotein methylamine dehydrogenase (MADH)-the much lower KIE of 11 that we obtain for the MADH/methylamine system is found to arise from a more endothermic potential energy surface for the MADH reaction.
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Affiliation(s)
- Laura Masgrau
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, and Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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41
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Abstract
Combined quantum-mechanics/molecular-mechanics (QM/MM) methods are making rapid progress both methodologically and with respect to their range of application. Mechanistic studies on enzymes, including contributions towards the understanding of enzyme catalysis, continue to be a major target. They are joined by calculations of pK(a) values, redox properties, ground- and excited-state spectroscopic parameters, and excited-state dynamics. Methodological advances include improved QM/MM schemes, in particular new approaches for an effective treatment of the QM-MM electrostatic interactions, and the incorporation of new efficient and accurate QM methods in QM/MM schemes.
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Affiliation(s)
- Hans Martin Senn
- Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim an der Ruhr, Germany
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42
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Lodola A, Mor M, Zurek J, Tarzia G, Piomelli D, Harvey JN, Mulholland AJ. Conformational effects in enzyme catalysis: reaction via a high energy conformation in fatty acid amide hydrolase. Biophys J 2006; 92:L20-2. [PMID: 17098788 PMCID: PMC1751413 DOI: 10.1529/biophysj.106.098434] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Quantum mechanics/molecular mechanics and molecular dynamics simulations of fatty acid amide hydrolase show that reaction (amide hydrolysis) occurs via a distinct, high energy conformation. This unusual finding has important implications for fatty acid amide hydrolase, a key enzyme in the endocannabinoid system. These results demonstrate the importance of structural fluctuations and the need to include them in the modeling of enzyme reactions. They also show that approaches based simply on studying enzyme-substrate complexes can be misleading for understanding biochemical reactivity.
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Gao J, Ma S, Major DT, Nam K, Pu J, Truhlar DG. Mechanisms and free energies of enzymatic reactions. Chem Rev 2006; 106:3188-209. [PMID: 16895324 PMCID: PMC4477011 DOI: 10.1021/cr050293k] [Citation(s) in RCA: 317] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jiali Gao
- Department of Chemistry and Supercomputing Institute, Digital Technology Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - Shuhua Ma
- Department of Chemistry and Supercomputing Institute, Digital Technology Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - Dan T. Major
- Department of Chemistry and Supercomputing Institute, Digital Technology Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - Kwangho Nam
- Department of Chemistry and Supercomputing Institute, Digital Technology Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - Jingzhi Pu
- Department of Chemistry and Supercomputing Institute, Digital Technology Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - Donald G. Truhlar
- Department of Chemistry and Supercomputing Institute, Digital Technology Center, University of Minnesota, Minneapolis, Minnesota 55455
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Giraldo J, Roche D, Rovira X, Serra J. The catalytic power of enzymes: Conformational selection or transition state stabilization? FEBS Lett 2006; 580:2170-7. [PMID: 16616138 DOI: 10.1016/j.febslet.2006.03.060] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Revised: 03/19/2006] [Accepted: 03/20/2006] [Indexed: 11/19/2022]
Abstract
The mechanism by which enzymes produce enormous rate enhancements in the reactions they catalyze remains unknown. Two viewpoints, selection of ground state conformations and stabilization of the transition state, are present in the literature in apparent opposition. To provide more insight into current discussion about enzyme efficiency, a two-state model of enzyme catalysis was developed. The model was designed to include both the pre-chemical (ground state conformations) and the chemical (transition state) components of the process for the substrate both in water and in the enzyme. Although the model is of general applicability, the chorismate to prephenate reaction catalyzed by chorismate mutase was chosen for illustrative purposes. The resulting kinetic equations show that the catalytic power of enzymes, quantified as the k(cat)/k(uncat) ratio, is the product of two terms: one including the equilibrium constants for the substrate conformational states and the other including the rate constants for the uncatalyzed and catalyzed chemical reactions. The model shows that these components are not mutually exclusive and can be simultaneously present in an enzymic system, being their relative contribution a property of the enzyme. The developed mathematical expressions reveal that the conformational and reaction components of the process perform differently for the translation of molecular efficiency (changes in energy levels) into observed enzymic efficiency (changes in k(cat)), being, in general, more productive the component involving the transition state.
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Affiliation(s)
- Jesús Giraldo
- Grup Biomatemàtic de Recerca, Institut de Neurociències and Unitat de Bioestadística, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
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Abstract
Modern modelling methods can now give uniquely detailed understanding of enzyme-catalyzed reactions, including the analysis of mechanisms and the identification of determinants of specificity and catalytic efficiency. A new field of computational enzymology has emerged that has the potential to contribute significantly to structure-based design and to develop predictive models of drug metabolism and, for example, of the effects of genetic polymorphisms. This review outlines important techniques in this area, including quantum-chemical model studies and combined quantum-mechanics and molecular-mechanics (QM/MM) methods. Some recent applications to enzymes of pharmacological interest are also covered, showing the types of problems that can be tackled and the insight they can give.
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Affiliation(s)
- Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
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Claeyssens F, Ranaghan KE, Manby FR, Harvey JN, Mulholland AJ. Multiple high-level QM/MM reaction paths demonstrate transition-state stabilization in chorismate mutase: correlation of barrier height with transition-state stabilization. Chem Commun (Camb) 2005:5068-70. [PMID: 16220173 DOI: 10.1039/b508181e] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multiple profiles for the reaction from chorismate to prephenate in the enzyme chorismate mutase calculated with hybrid density functional combined quantum mechanics/molecular mechanics methods (B3LYP/6-31G(d)-CHARMM27) agree well with experiment, and provide direct evidence of transition-state stabilization by this important enzyme, which is at the centre of current debates about the nature of enzyme catalysis.
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