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Mechanism for the synthesis of medium-chain 1-alkenes from fatty acids catalyzed by binuclear iron UndA decarboxylase. J Catal 2023. [DOI: 10.1016/j.jcat.2023.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
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2
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Cao YC, Liao RZ. QM Calculations Revealed that Outer-Sphere Electron Transfer Boosted O-O Bond Cleavage in the Multiheme-Dependent Cytochrome bd Oxygen Reductase. Inorg Chem 2023; 62:4066-4075. [PMID: 36857027 DOI: 10.1021/acs.inorgchem.2c03742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
The cytochrome bd oxygen reductase catalyzes the four-electron reduction of dioxygen to two water molecules. The structure of this enzyme reveals three heme molecules in the active site, which differs from that of heme-copper cytochrome c oxidase. The quantum chemical cluster approach was used to uncover the reaction mechanism of this intriguing metalloenzyme. The calculations suggested that a proton-coupled electron transfer reduction occurs first to generate a ferrous heme b595. This is followed by the dioxygen binding at the heme d center coupled with an outer-sphere electron transfer from the ferrous heme b595 to the dioxygen moiety, affording a ferric ion superoxide intermediate. A second proton-coupled electron transfer produces a heme d ferric hydroperoxide, which undergoes efficient O-O bond cleavage facilitated by an outer-sphere electron transfer from the ferrous heme b595 to the O-O σ* orbital and an inner-sphere proton transfer from the heme d hydroxyl group to the leaving hydroxide. The synergistic benefits of the two types of hemes rationalize the highly efficient oxygen reduction repertoire for the multi-heme-dependent cytochrome bd oxygen reductase family.
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Affiliation(s)
- Yu-Chen Cao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Rong-Zhen Liao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
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3
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Su JX, Chen SL. A Key Piece in the Global N-Cycle: The N–N Bond Formation Presented by Heme-Dependent Hydrazine Synthase. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Jing-Xuan Su
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Shi-Lu Chen
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
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4
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Teder T, Samel N, Lõhelaid H. Distinct characteristics of the substrate binding between highly homologous catalase-related allene oxide synthase and hydroperoxide lyase. Arch Biochem Biophys 2019; 676:108126. [PMID: 31589830 DOI: 10.1016/j.abb.2019.108126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/30/2019] [Accepted: 10/02/2019] [Indexed: 11/15/2022]
Abstract
A catalase-related allene oxide synthase (cAOS) or a hydroperoxide lyase (cHPL) fused together with an 8R-lipoxygenase is involved in the stress signaling of corals via an arachidonic acid pathway. cAOS gives rise to α-ketol and cyclopentenone, while cHPL catalyzes the cleavage of 8R-hydroperoxyeicosatetraenoic acid (8R-HpETE) to C8-oxo acid and C12 aldehyde. In silico analysis of the substrate entry sites of highly identical coral cAOS and cHPL indicated that two positively charged residues of cAOS, K60 and K107, and the corresponding residues of cHPL, E60 and K107, may be involved in the anchoring of the carboxy group of polyunsaturated fatty acid (PUFA) hydroperoxides. A mutational analysis of cAOS and cHPL revealed that K60 or E60 and K107 were not necessary in the tethering of 8R-HpETE, however, the E60 of cHPL was essential in the productive binding of PUFA hydroperoxides. The substrate preferences of cAOS and cHPL were determined with hydroperoxy derivatives of C18, C20, C22 PUFAs, anandamide (AEA), 1-arachidonoyl glycerol (1-AG) and selected methylated substrates. Although cAOS and cHPL were able to metabolize different free PUFA substrates and arachidonoyl derivatives, only cHPL catalyzed the reaction with methylated PUFA hydroperoxides. The differences in the substrate binding and preferences between cAOS and cHPL can be explained by the distinct properties of their substrate entry sites. The current study demonstrated that homologous PUFA metabolizing enzymes may contribute to the versatile usage of the substrate pool.
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Affiliation(s)
- Tarvi Teder
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Nigulas Samel
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Helike Lõhelaid
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia.
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5
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Yu MJ, Wu J, Chen SL. Mechanism and Inhibitor Exploration with Binuclear Mg Ketol-Acid Reductoisomerase: Targeting the Biosynthetic Pathway of Branched-Chain Amino Acids. Chembiochem 2019; 21:381-391. [PMID: 31309701 DOI: 10.1002/cbic.201900363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Indexed: 01/01/2023]
Abstract
Binuclear Mg ketol-acid reductoisomerase (KARI), which converts (S)-2-acetolactate into (R)-2,3-dihydroxyisovalerate, is responsible for the second step of the biosynthesis of branched-chain amino acids in plants and microorganisms and thus serves as a key inhibition target potentially without effects on mammals. Here, through the use of density functional calculations and a chemical model, the KARI-catalyzed reaction has been demonstrated to include the initial deprotonation of the substrate C2 hydroxy group, bridged by the two Mg ions, alkyl migration from the C2-alkoxide carbon atom to the C3-carbonyl carbon atom, and hydride transfer from a nicotinamide adenine dinucleotide phosphate [NAD(P)H] cofactor to C2. A dead-end mechanism with a hydride transferred to the C3 carbonyl group has been ruled out. The nucleophilicity (migratory aptitude) of the migrating carbon atom and the provision of additional negative charge to the di-Mg coordination sphere have significant effects on the steps of alkyl migration and hydride transfer, respectively. Other important mechanistic characteristics are also revealed. Inspired by the mechanism, an inhibitor (2-carboxylate-lactic acid) was designed and predicted by barrier analysis to be effective in inactivating KARI, hence probably enriching the antifungal and antibacterial library. Two types of slow substrate analogues (2-trihalomethyl acetolactic acids and 2-glutaryl lactic acid) were also found.
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Affiliation(s)
- Ming-Jia Yu
- Key Laboratory of Cluster Science of the Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Jue Wu
- Key Laboratory of Cluster Science of the Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Shi-Lu Chen
- Key Laboratory of Cluster Science of the Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
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6
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Sun SQ, Chen SL. How does Mo-dependent perchlorate reductase work in the decomposition of oxyanions? Dalton Trans 2019; 48:5683-5691. [DOI: 10.1039/c9dt00863b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The mechanisms of Mo-dependent perchlorate reductase (PcrAB)-catalyzed decomposition of perchlorate, bromate, iodate, and nitrate were revealed by density functional calculations.
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Affiliation(s)
- Shuo-Qi Sun
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- China
| | - Shi-Lu Chen
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- China
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7
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How does binuclear zinc amidohydrolase FwdA work in the initial step of methanogenesis: From formate to formyl-methanofuran. J Inorg Biochem 2018; 185:71-79. [PMID: 29778928 DOI: 10.1016/j.jinorgbio.2018.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/05/2018] [Accepted: 05/08/2018] [Indexed: 11/22/2022]
Abstract
The initial step of methanogenesis is the fixation of CO2 to formyl-methanofuran (formyl-MFR) catalyzed by formyl-MFR dehydrogenase, which can be divided into two half reactions. Herein, the second half reaction catalyzed by FwdA (formyl-methanofuran dehydrogenase subunit A), i.e., from formate to formyl-methanofuran, has been investigated using density functional theory and a chemical model based on the X-ray crystal structure. The calculations indicate that, compared with other well-known di-zinc hydrolases, the FwdA reaction employs a reverse mechanism, including the nucleophilic attack of MFR amine on formate carbon leading to a tetrahedral gem-diolate intermediate, two steps of proton transfer from amine to formate moieties assisted by the Asp385, and the CO bond dissociation to form the formyl-MFR product. The second step of proton transfer from the amine moiety to the Asp385 is rate-limiting with an overall barrier of 21.2 kcal/mol. The two zinc ions play an important role in stabilizing the transition states and intermediates, in particular the negative charge at the formate moiety originated from the nucleophilic attack of the MFR amine. The work here appends a crucial piece in the methanogenic mechanistics and advances the understanding of the global carbon cycle.
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9
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Yu MJ, Chen SL. From NAD + to Nickel Pincer Complex: A Significant Cofactor Evolution Presented by Lactate Racemase. Chemistry 2017; 23:7545-7557. [PMID: 28374531 DOI: 10.1002/chem.201700405] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Indexed: 02/02/2023]
Abstract
Lactate racemase (LarA), a new nickel enzyme discovered recently, catalyzes the racemization between d- and l-lactates with a novel nickel pincer cofactor (Ni-PTTMN) derived from nicotinic acid. In this study, by using DFT and a 200-atom active-site model, LarA is revealed to employ a modified proton-coupled hydride-transfer mechanism in which a hydride is transferred to a cofactor pyridine carbon from the substrate α-carbon along with proton transfer from the substrate hydroxy group to a histidine, and then moved back from the opposite side. Tyr294 and Lys298 provide significant acceleration effects by orientating substrates and stabilizing the negative charge developing at the substrate hydroxy oxygen. The barrier was determined to be 12.0 kcal mol-1 , which reveals enhanced racemase activity relative to the LarA reaction using NAD+ -like cofactors. Compared with NAD+ , Ni-PTTMN has a stronger hydride-addition reactivity in moderate and high environmental polarity and may fit perfectly the moderately polar active site of LarA.
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Affiliation(s)
- Ming-Jia Yu
- Key Laboratory of Cluster Science of the Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P.R. China
| | - Shi-Lu Chen
- Key Laboratory of Cluster Science of the Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P.R. China
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10
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11
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Wei WJ, Siegbahn PEM, Liao RZ. Theoretical Study of the Mechanism of the Nonheme Iron Enzyme EgtB. Inorg Chem 2017; 56:3589-3599. [PMID: 28277674 DOI: 10.1021/acs.inorgchem.6b03177] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
EgtB is a nonheme iron enzyme catalyzing the C-S bond formation between γ-glutamyl cysteine (γGC) and N-α-trimethyl histidine (TMH) in the ergothioneine biosynthesis. Density functional calculations were performed to elucidate and delineate the reaction mechanism of this enzyme. Two different mechanisms were considered, depending on whether the sulfoxidation or the S-C bond formation takes place first. The calculations suggest that the S-O bond formation occurs first between the thiolate and the ferric superoxide, followed by homolytic O-O bond cleavage, very similar to the case of cysteine dioxygenase. Subsequently, proton transfer from a second-shell residue Tyr377 to the newly generated iron-oxo moiety takes place, which is followed by proton transfer from the TMH imidazole to Tyr377, facilitated by two crystallographically observed water molecules. Next, the S-C bond is formed between γGC and TMH, followed by proton transfer from the imidazole CH moiety to Tyr377, which was calculated to be the rate-limiting step for the whole reaction, with a barrier of 17.9 kcal/mol in the quintet state. The calculated barrier for the rate-limiting step agrees quite well with experimental kinetic data. Finally, this proton is transferred back to the imidazole nitrogen to form the product. The alternative thiyl radical attack mechanism has a very high barrier, being 25.8 kcal/mol, ruling out this possibility.
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Affiliation(s)
- Wen-Jie Wei
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan 430074, China
| | - Per E M Siegbahn
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University , SE-10691 Stockholm, Sweden
| | - Rong-Zhen Liao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan 430074, China
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12
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Lan CL, Chen SL. The Decarboxylation of α,β-Unsaturated Acid Catalyzed by Prenylated FMN-Dependent Ferulic Acid Decarboxylase and the Enzyme Inhibition. J Org Chem 2016; 81:9289-9295. [PMID: 27618344 DOI: 10.1021/acs.joc.6b01872] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ferulic acid decarboxylase (Fdc1) is able to catalyze the decarboxylation of α,β-unsaturated acids using a novel cofactor, prenylated flavin mononucleotide (PrFMN). Using density functional theory calculations, we here have investigated the Fdc1 reaction mechanism with the substrate of α-methylcinnamic acid. It is demonstrated that Fdc1 employs a 1,3-dipolar cycloaddition mechanism involving four concerted steps, where the Glu282 acts as a crucial proton donor to protonate the α carbon (Cα). The last step, the decomposition of a pyrrolidine species, is rate-limiting with an overall barrier of 18.9 kcal mol-1. Furthermore, when α-hydroxycinnamic acid is used, the Glu282 is found to have another face to transport the hydroxyl proton to the Cβ atom to promote the tautomerization from enol intermediate to ketone species leading to the inhibition of the Fdc1 enzyme. The PrFMN roles are also discussed in detail.
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Affiliation(s)
- Cui-Lan Lan
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology , Beijing 100081, China
| | - Shi-Lu Chen
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology , Beijing 100081, China
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13
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MacDonald CA, Boyd RJ. Computational insights into the suicide inhibition of Plasmodium falciparum Fk506-binding protein 35. Bioorg Med Chem Lett 2015; 25:3221-5. [PMID: 26091727 DOI: 10.1016/j.bmcl.2015.05.079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/25/2015] [Accepted: 05/26/2015] [Indexed: 02/08/2023]
Abstract
Malaria is a parasite affecting millions of people worldwide. With the risk of malarial resistance reaching catastrophic levels, novel methods into the inhibition of this disease need to be prioritized. The exploitation of active site differences between parasitic and human peptidyl-prolyl cis/trans isomerases can be used for suicide inhibition, effectively poisoning the parasite without affecting the patient. This method of inhibition was explored using Plasmodium falciparum and Homo sapiens Fk506-binding proteins as templates for quantum mechanics/molecular mechanics calculations. Modification of the natural substrate has shown suicide inhibition is a valid approach for novel anti-malarials with little risk for parasitic resistance.
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Affiliation(s)
- Corey A MacDonald
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - Russell J Boyd
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada.
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14
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MacDonald CA, Bushnell EAC, Gauld JW, Boyd RJ. The catalytic formation of leukotriene C4: a critical step in inflammatory processes. Phys Chem Chem Phys 2015; 16:16284-9. [PMID: 24974917 DOI: 10.1039/c4cp01984a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Leukotrienes (LT) are a family of drug-like molecules involved in the pathobiology of bronchial asthma and are responsible for smooth muscle contraction. Leukotriene C4 synthase (LTC4S) is a nuclear-membrane enzyme responsible for the conjugation of leukotriene A4 (LTA4) to glutathione to form LTC4, a cysteinyl leukotriene. In this study, the mechanism of LTA4 binding by LTC4S has been computationally examined. More specifically, docking and molecular dynamics simulations were used to gain insight into the substrate-bound active site. These studies identified two possible orientations for bound LTA4: 'tail-to-head' and 'head-to-tail'. An ONIOM(QM/MM) approach was then used to elucidate the mechanism by which glutathione may add to LTA4. In particular, the thiolate of glutathione acts as a nucleophile attacking C6 of LTA4 forming a S-C6 bond. Concomitantly, a proton is transferred from the guanidinium of Arg31 to the epoxide ring oxygen. This results in opening of the epoxide ring and stabilization of the LTC4 product complex. Within the present computational methodology the 'tail-to-head' orientation appears to be the most likely substrate orientation.
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Affiliation(s)
- Corey A MacDonald
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
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15
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Audran G, Brémond P, Marque SR, Siri D, Santelli M. Energetics of the biosynthesis of cyclopentenones from unsaturated fatty acids. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.09.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Ion BF, Kazim E, Gauld JW. A multi-scale computational study on the mechanism of Streptococcus pneumoniae Nicotinamidase (SpNic). Molecules 2014; 19:15735-53. [PMID: 25268724 PMCID: PMC6271260 DOI: 10.3390/molecules191015735] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 09/20/2014] [Accepted: 09/22/2014] [Indexed: 11/16/2022] Open
Abstract
Nicotinamidase (Nic) is a key zinc-dependent enzyme in NAD metabolism that catalyzes the hydrolysis of nicotinamide to give nicotinic acid. A multi-scale computational approach has been used to investigate the catalytic mechanism, substrate binding and roles of active site residues of Nic from Streptococcus pneumoniae (SpNic). In particular, density functional theory (DFT), molecular dynamics (MD) and ONIOM quantum mechanics/molecular mechanics (QM/MM) methods have been employed. The overall mechanism occurs in two stages: (i) formation of a thioester enzyme-intermediate (IC2) and (ii) hydrolysis of the thioester bond to give the products. The polar protein environment has a significant effect in stabilizing reaction intermediates and in particular transition states. As a result, both stages effectively occur in one step with Stage 1, formation of IC2, being rate limiting barrier with a cost of 53.5 kJ·mol-1 with respect to the reactant complex, RC. The effects of dispersion interactions on the overall mechanism were also considered but were generally calculated to have less significant effects with the overall mechanism being unchanged. In addition, the active site lysyl (Lys103) is concluded to likely play a role in stabilizing the thiolate of Cys136 during the reaction.
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Affiliation(s)
- Bogdan F Ion
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Erum Kazim
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - James W Gauld
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada.
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17
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Sheng X, Liu Y, Zhang R. A theoretical study of the catalytic mechanism of oxalyl-CoA decarboxylase, an enzyme for treating urolithiasis. RSC Adv 2014. [DOI: 10.1039/c4ra03611e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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Somboon T, Ochiai J, Treesuwan W, Gleeson MP, Hannongbua S, Mori S. Mechanistic insights into the catalytic reaction of plant allene oxide synthase (pAOS) via QM and QM/MM calculations. J Mol Graph Model 2014; 52:20-9. [PMID: 24984079 DOI: 10.1016/j.jmgm.2014.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 05/29/2014] [Accepted: 05/30/2014] [Indexed: 11/26/2022]
Abstract
QM cluster and QM/MM protein models have been employed to understand aspects of the reaction mechanism of plant allene oxide synthase (pAOS). In this study we have investigated two reaction mechanisms for pAOS. The standard pAOS mechanism was contrasted with an alternative involving an additional active site molecule which has been shown to facilitate proton coupled electron transfer (PCET) in related systems. Firstly, we found that the results from QM/MM protein model are comparable with those from the QM cluster model, presumably due to the large active site used. Furthermore, the results from the QM cluster model show that the Fe(III) and Fe(IV) pathways for the standard mechanism have similar energetic and structural properties, indicating that the reaction mechanism may well proceed via both pathways. However, while the PCET process is facilitated by an additional active site bound water in other related families, in pAOS it is not, suggesting this type of process is not general to all closely related family members.
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Affiliation(s)
- Tuanjai Somboon
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - Jun Ochiai
- Faculty of Science, Ibaraki University, Ibaraki 310-8512, Japan
| | - Witcha Treesuwan
- Institute of Food Research and Product Development, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - M Paul Gleeson
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - Supa Hannongbua
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand; Center of Nanotechnology KU, Kasetsart University, Chatuchak, Bangkok 10900 Thailand.
| | - Seiji Mori
- Faculty of Science, Ibaraki University, Ibaraki 310-8512, Japan; Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Tokai, Ibaraki 319-1106, Japan.
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Multi-scale computational enzymology: enhancing our understanding of enzymatic catalysis. Int J Mol Sci 2013; 15:401-22. [PMID: 24384841 PMCID: PMC3907816 DOI: 10.3390/ijms15010401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 12/05/2013] [Accepted: 12/24/2013] [Indexed: 01/23/2023] Open
Abstract
Elucidating the origin of enzymatic catalysis stands as one the great challenges of contemporary biochemistry and biophysics. The recent emergence of computational enzymology has enhanced our atomistic-level description of biocatalysis as well the kinetic and thermodynamic properties of their mechanisms. There exists a diversity of computational methods allowing the investigation of specific enzymatic properties. Small or large density functional theory models allow the comparison of a plethora of mechanistic reactive species and divergent catalytic pathways. Molecular docking can model different substrate conformations embedded within enzyme active sites and determine those with optimal binding affinities. Molecular dynamics simulations provide insights into the dynamics and roles of active site components as well as the interactions between substrate and enzymes. Hybrid quantum mechanical/molecular mechanical (QM/MM) can model reactions in active sites while considering steric and electrostatic contributions provided by the surrounding environment. Using previous studies done within our group, on OvoA, EgtB, ThrRS, LuxS and MsrA enzymatic systems, we will review how these methods can be used either independently or cooperatively to get insights into enzymatic catalysis.
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De Luna P, Bushnell EAC, Gauld JW. A Molecular Dynamics Examination on Mutation-Induced Catalase Activity in Coral Allene Oxide Synthase. J Phys Chem B 2013; 117:14635-41. [DOI: 10.1021/jp408486n] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Phil De Luna
- Department
of Chemistry and
Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Eric A. C. Bushnell
- Department
of Chemistry and
Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - James W. Gauld
- Department
of Chemistry and
Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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