1
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Chen Y, Miller CJ, Xie J, Waite TD. Challenges Relating to the Quantification of Ferryl(IV) Ion and Hydroxyl Radical Generation Rates Using Methyl Phenyl Sulfoxide (PMSO), Phthalhydrazide, and Benzoic Acid as Probe Compounds in the Homogeneous Fenton Reaction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18617-18625. [PMID: 36721331 DOI: 10.1021/acs.est.2c06753] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Ferryl ion ([FeIVO]2+) has often been suggested to play a role in iron-based advanced oxidation processes (AOPs) with its presence commonly determined using the unique oxidation pathway from methyl phenyl sulfoxide (PMSO) to methyl phenyl sulfone (PMSO2). However, we show here that the oxidation products of PMSO, formed on reaction with hydroxyl radical, enhance PMSO2 formation as a result of their complexation with Fe(III) leading to the changes in the reactivity of Fe(III) species in the homogeneous Fenton reaction. As such, PMSO should be used with caution to investigate the role of [FeIVO]2+ in iron-based AOPs with these insights suggesting the need to reassess the findings of many previous studies in which this reagent was used. The other common target compounds, phthalhydrazide and hydroxybenzoic acids, were also found to modify the rate and extent of iron cycling as a result of complexation and/or redox reactions, either by the probe compound itself and/or oxidation products formed. Overall, this study highlights that these confounding effects of the aromatic probe compounds on the reactivity of iron species should be recognized if reliable mechanistic insights into iron-based AOPs are to be obtained.
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Affiliation(s)
- Yufan Chen
- School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales2052, Australia
| | - Christopher J Miller
- School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales2052, Australia
| | - Jieli Xie
- School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales2052, Australia
| | - T David Waite
- School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales2052, Australia
- UNSW Centre for Transformational Environmental Technologies (CTET), Yixing, Jiangsu Province214206, P. R. China
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2
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Gérard E, Mokkawes T, Johannissen LO, Warwicker J, Spiess RR, Blanford CF, Hay S, Heyes DJ, de Visser SP. How Is Substrate Halogenation Triggered by the Vanadium Haloperoxidase from Curvularia inaequalis? ACS Catal 2023; 13:8247-8261. [PMID: 37342830 PMCID: PMC10278073 DOI: 10.1021/acscatal.3c00761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 05/05/2023] [Indexed: 06/23/2023]
Abstract
Vanadium haloperoxidases (VHPOs) are unique enzymes in biology that catalyze a challenging halogen transfer reaction and convert a strong aromatic C-H bond into C-X (X = Cl, Br, I) with the use of a vanadium cofactor and H2O2. The VHPO catalytic cycle starts with the conversion of hydrogen peroxide and halide (X = Cl, Br, I) into hypohalide on the vanadate cofactor, and the hypohalide subsequently reacts with a substrate. However, it is unclear whether the hypohalide is released from the enzyme or otherwise trapped within the enzyme structure for the halogenation of organic substrates. A substrate-binding pocket has never been identified for the VHPO enzyme, which questions the role of the protein in the overall reaction mechanism. Probing its role in the halogenation of small molecules will enable further engineering of the enzyme and expand its substrate scope and selectivity further for use in biotechnological applications as an environmentally benign alternative to current organic chemistry synthesis. Using a combined experimental and computational approach, we elucidate the role of the vanadium haloperoxidase protein in substrate halogenation. Activity studies show that binding of the substrate to the enzyme is essential for the reaction of the hypohalide with substrate. Stopped-flow measurements demonstrate that the rate-determining step is not dependent on substrate binding but partially on hypohalide formation. Using a combination of molecular mechanics (MM) and molecular dynamics (MD) simulations, the substrate binding area in the protein is identified and even though the selected substrates (methylphenylindole and 2-phenylindole) have limited hydrogen-bonding abilities, they are found to bind relatively strongly and remain stable in a binding tunnel. A subsequent analysis of the MD snapshots characterizes two small tunnels leading from the vanadate active site to the surface that could fit small molecules such as hypohalide, halide, and hydrogen peroxide. Density functional theory studies using electric field effects show that a polarized environment in a specific direction can substantially lower barriers for halogen transfer. A further analysis of the protein structure indeed shows a large dipole orientation in the substrate-binding pocket that could enable halogen transfer through an applied local electric field. These findings highlight the importance of the enzyme in catalyzing substrate halogenation by providing an optimal environment to lower the energy barrier for this challenging aromatic halide insertion reaction.
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Affiliation(s)
- Emilie
F. Gérard
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
| | - Thirakorn Mokkawes
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
| | - Linus O. Johannissen
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Jim Warwicker
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- School
of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester 13 9PL, United
Kingdom
| | - Reynard R. Spiess
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Christopher F. Blanford
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department
of Materials, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Sam Hay
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Derren J. Heyes
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Sam P. de Visser
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
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3
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Abstract
Enzymes fold into three-dimensional structures to distribute amino acid residues for catalysis, which inspired the supramolecular approach to construct enzyme-mimicking catalysts. A key concern in the development of supramolecular strategies is the ability to confine and orient functional groups to form enzyme-like active sites in artificial materials. This review introduces the design principles and construction of supramolecular nanomaterials exhibiting catalytic functions of heme-dependent enzymes, a large class of metalloproteins, which rely on a heme cofactor and spatially configured residues to catalyze diverse reactions via a complex multistep mechanism. We focus on the structure-activity relationship of the supramolecular catalysts and their applications in materials synthesis/degradation, biosensing, and therapeutics. The heme-free catalysts that catalyze reactions achieved by hemeproteins are also briefly discussed. Towards the end of the review, we discuss the outlook on the challenges related to catalyst design and future prospective, including the development of structure-resolving techniques and design concepts, with the aim of creating enzyme-mimicking materials that possess catalytic power rivaling that of natural enzymes..
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Affiliation(s)
- Yuanxi Liu
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Ministry of Education), Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zhen-Gang Wang
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Ministry of Education), Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
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4
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Jeong D, Selverstone Valentine J, Cho J. Bio-inspired mononuclear nonheme metal peroxo complexes: Synthesis, structures and mechanistic studies toward understanding enzymatic reactions. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2023.215021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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5
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Kaur L, Mandal D. Role of "S" Substitution on C-H Activation Reactivity of Iron(IV)-Oxo Cyclam Complexes: a Computational Investigation. Inorg Chem 2022; 61:14582-14590. [PMID: 36069431 DOI: 10.1021/acs.inorgchem.2c01504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A comprehensive density functional theory (DFT) investigation has been presented in this article to address the role of equatorial sulfur ligation in C-H activation. A non-heme iron-oxo compound with four nitrogen atoms constituting the equatorially connected macrocyclic framework (represented as N4) [Fe(IV)═O(THC)(CH3CN)]2+(THC = 1,4,8,11-tetrahydro1,4,8,11-tetraazacyclotetradecane) has been considered as the base compound. Other complexes have been anticipated by the sequential replacement of this nitrogen by sulfur, that is, N4, N3S1, N2S2, N1S3, and S4. Counterions, as always, have been considered to avoid the self-interaction error in DFT. Generally, the anti-conformers (with respect to equatorial N-H and Fe═O) turned out to be the most stable. It was found that with the enrichment of the equatorial sulfur atom, reactivity increases successively, that is, we get the trend N4 < N3S1 < N2S2 < N1S3 < S4. Our investigations have also verified the available experimental results where it has been reported that N2S2 is more reactive than N4 in their mixed conformation. In search of insights into this typical pattern of reactivity, the interplay of several factors has been recognized, such as the distortion energy which decreases for the transition states with the addition of sulfur; the spin density on the oxygen atom which increases implying that the radical character of abstractor increases on sulfur ligation; the energy of the electron acceptor orbital (the lowest unoccupied molecular orbital (σz2*)) which decreases continuously with the sulfur substitution; and the triplet-quintet oxidant energy gap which decreases consistently with S enrichment in the equatorial position. The computational predictions reported here, if further validated by experiments, will definitely encourage the synthesis of sulfur-ligated bio-inspired complexes instead of the ones constituting nitrogen exclusively.
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Affiliation(s)
- Lovleen Kaur
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India
| | - Debasish Mandal
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India
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6
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Engbers S, Hage R, Klein JEMN. Toward Environmentally Benign Electrophilic Chlorinations: From Chloroperoxidase to Bioinspired Isoporphyrins. Inorg Chem 2022; 61:8105-8111. [PMID: 35574587 PMCID: PMC9157495 DOI: 10.1021/acs.inorgchem.2c00602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Silène Engbers
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen , The Netherlands
| | - Ronald Hage
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen , The Netherlands
- Catexel BV, BioPartner Center Leiden, Galileiweg 8, Leiden 2333 BD, The Netherlands
| | - Johannes E. M. N. Klein
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen , The Netherlands
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7
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Zhang S, Li X, Wang Y, Wei J, Zhang X, Liu Y. Computational Study of the Peroxygenase Mechanism Catalyzed by Hemoglobin Dehaloperoxidase Involved in the Degradation of Chlorophenols. Inorg Chem 2022; 61:2628-2639. [PMID: 35080380 DOI: 10.1021/acs.inorgchem.1c03721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The biochemical evidence showed that hemoglobin dehaloperoxidase (DHP B) from Amphitrite Ornata is a multifunctional hemoprotein that catalyzes both dehalogenation and hydroxylation of halophenols via the peroxidase and peroxygenase mechanism, respectively, which sets the basis for the degradation of halophenols. In the peroxygenase mechanism, the reaction was previously suggested to be triggered either by the hydrogen atom abstraction by the Fe═O center or by the proton abstraction by His55. To illuminate the peroxygenase mechanism of DHP B at the atomistic level, on the basis of the high-resolution crystal structure, computational models were constructed, and a series of quantum mechanical/molecular mechanical calculations have been performed. According to the calculation results, the pathway (Path a) initiated by the H-abstraction by the Fe═O center is feasible. In another pathway (Path b), His55 can abstract the proton from the hydroxyl group of the substrate (4-Cl-o-cresol) to initiate the reaction; however, its feasibility depends on the prior electron transfer from the substrate to the porphyrin group. The rate-limiting step of Path a is the OH-rebound, which corresponds to an energy barrier of 14.7 kcal/mol at the quartet state. His55 acts as an acid-base catalyst and directly involves in the catalysis. Our mutant study indicates that His55 can be replaced by other titratable residues. These findings may provide useful information for further understanding of the catalytic reaction of DHP B and for the design of enzymes in the degradation of pollutants, in particular, halophenols.
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Affiliation(s)
- Shiqing Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Xinyi Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yijing Wang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Jingjing Wei
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Xue Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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8
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Tian G, Hao G, Chen X, Liu Y. Tyrosyl Radical-Mediated Sequential Oxidative Decarboxylation of Coproporphyrinogen III through PCET: Theoretical Insights into the Mechanism of Coproheme Decarboxylase ChdC. Inorg Chem 2021; 60:13539-13549. [PMID: 34382397 DOI: 10.1021/acs.inorgchem.1c01864] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The peroxide-dependent coproheme decarboxylase ChdC from Geobacillus stearothermophilus catalyzes two key steps in the synthesis of heme b, i.e., two sequential oxidative decarboxylations of coproporphyrinogen III (coproheme III) at propionate groups P2 and P4. In the binding site of coproheme III, P2 and P4 are anchored by different residues (Tyr144, Arg217, and Ser222 for P2 and Tyr113, Lys148, and Trp156 for P4); however, strong experimental evidence supports that the generated Tyr144 radical acts as an unique intermediary for hydrogen atom transfer (HAT) from both reactive propionates. So far, the reaction details are still unclear. Herein, we carried out quantum mechanics/molecular mechanics calculations to explore the decarboxylation mechanism of coproheme III. In our calculations, the coproheme Cpd I, Fe(IV) = O coupled to a porphyrin radical cation (por•+) with four propionate groups, was used as a reactant model. Our calculations reveal that Tyr144 is directly involved in the decarboxylation of propionate group P2. First, the proton-coupled electron transfer (PCET) occurs from Tyr144 to P2, generating a Tyr144 radical, which then abstracts a hydrogen atom from the Cβ of P2. The β-H extraction was calculated to be the rate-limiting step of decarboxylation. It is the porphyrin radical cation (por•+) that makes the PCET from Tyr144 to P2 to be quite easy to initiate the decarboxylation. Finally, the electron transfers from the Cβ• through the porphyrin to the iron center, leading to the decarboxylation of P2. Importantly, the decarboxylation of P4 mediated by Lys148 was calculated to be very difficult, which suggests that after the P2 decarboxylation, the generated harderoheme III intermediate should rebind or rotate in the active site so that the propionate P4 occupies the binding site of P2, and Tyr144 again mediates the decarboxylation of P4. Thus, our calculations support the fact that Tyr144 is responsible for the decarboxylation of both P2 and P4.
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Affiliation(s)
- Ge Tian
- School of Life Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong 271000, China.,School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Gangping Hao
- School of Life Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong 271000, China
| | - Xiaohua Chen
- National-Municipal Joint Engineering Laboratory for Chemical Process Intensification and Reaction, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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9
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Lučić M, Wilson MT, Svistunenko DA, Owen RL, Hough MA, Worrall JAR. Aspartate or arginine? Validated redox state X-ray structures elucidate mechanistic subtleties of Fe IV = O formation in bacterial dye-decolorizing peroxidases. J Biol Inorg Chem 2021; 26:743-761. [PMID: 34477969 PMCID: PMC8463360 DOI: 10.1007/s00775-021-01896-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/23/2021] [Indexed: 11/26/2022]
Abstract
Structure determination of proteins and enzymes by X-ray crystallography remains the most widely used approach to complement functional and mechanistic studies. Capturing the structures of intact redox states in metalloenzymes is critical for assigning the chemistry carried out by the metal in the catalytic cycle. Unfortunately, X-rays interact with protein crystals to generate solvated photoelectrons that can reduce redox active metals and hence change the coordination geometry and the coupled protein structure. Approaches to mitigate such site-specific radiation damage continue to be developed, but nevertheless application of such approaches to metalloenzymes in combination with mechanistic studies are often overlooked. In this review, we summarize our recent structural and kinetic studies on a set of three heme peroxidases found in the bacterium Streptomyces lividans that each belong to the dye decolourizing peroxidase (DyP) superfamily. Kinetically, each of these DyPs has a distinct reactivity with hydrogen peroxide. Through a combination of low dose synchrotron X-ray crystallography and zero dose serial femtosecond X-ray crystallography using an X-ray free electron laser (XFEL), high-resolution structures with unambiguous redox state assignment of the ferric and ferryl (FeIV = O) heme species have been obtained. Experiments using stopped-flow kinetics, solvent-isotope exchange and site-directed mutagenesis with this set of redox state validated DyP structures have provided the first comprehensive kinetic and structural framework for how DyPs can modulate their distal heme pocket Asp/Arg dyad to use either the Asp or the Arg to facilitate proton transfer and rate enhancement of peroxide heterolysis.
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Affiliation(s)
- Marina Lučić
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Michael T Wilson
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Dimitri A Svistunenko
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Robin L Owen
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, Oxfordshire, UK
| | - Michael A Hough
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Jonathan A R Worrall
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
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10
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Cheng Q, DeYonker NJ. QM-Cluster Model Study of the Guaiacol Hydrogen Atom Transfer and Oxygen Rebound with Cytochrome P450 Enzyme GcoA. J Phys Chem B 2021; 125:3296-3306. [PMID: 33784103 DOI: 10.1021/acs.jpcb.0c10761] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The key step of the O-demethylation of guaiacol by GcoA of the cytochrome P450-reductase pair was studied with DFT using two 10-residue and three 15-residue QM-cluster models. For each model, two reaction pathways were examined, beginning with a different guaiacol orientation. Based on this study, His354, Phe349, Glu249, and Pro250 residues were found to be important for keeping the heme in a planar geometry throughout the reaction. Val241 and Gly245 residues were needed in the QM-cluster models to provide the hydrophobic pocket for an appropriate guaiacol pose in the reaction. The aromatic triad Phe75, Phe169, and Phe395 may be necessary to facilitate guaiacol migrating into the enzyme active site, but it does not qualitatively affect kinetics and thermodynamics of the proposed mechanism. All QM-cluster models created by RINRUS agree very well with previous experimental work. This study provides details for better understanding enzymatic O-demethylation of lignins to form catechol derivatives by GcoA.
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Affiliation(s)
- Qianyi Cheng
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, United States
| | - Nathan J DeYonker
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, United States
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11
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Deutscher J, Gerschel P, Warm K, Kuhlmann U, Mebs S, Haumann M, Dau H, Hildebrandt P, Apfel UP, Ray K. A bioinspired oxoiron(IV) motif supported on a N 2S 2 macrocyclic ligand. Chem Commun (Camb) 2021; 57:2947-2950. [PMID: 33621306 DOI: 10.1039/d1cc00250c] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A mononuclear oxoiron(iv) complex 1-trans bearing two equatorial sulfur ligations is synthesized and characterized as an active-site model of the elusive sulfur-ligated FeIV[double bond, length as m-dash]O intermediates in non-heme iron oxygenases. The introduction of sulfur ligands weakens the Fe[double bond, length as m-dash]O bond and enhances the oxidative reactivity of the FeIV[double bond, length as m-dash]O unit with a diminished deuterium kinetic isotope effect, thereby providing a compelling rationale for nature's use of the cis-thiolate ligated oxoiron(iv) motif in key metabolic transformations.
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Affiliation(s)
- Jennifer Deutscher
- Institut für Chemie Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany.
| | - Philipp Gerschel
- Anorganische Chemie 1 Ruhr-Universität Bochum, Universitätsstraße 150, 44780, Bochum, Germany
| | - Katrin Warm
- Institut für Chemie Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany.
| | - Uwe Kuhlmann
- Institut für Chemie Technische, Universität Berlin, Fakultät II Straße des 17, Juni 135, 10623, Berlin, Germany
| | - Stefan Mebs
- Institut für Physik Freie, Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Michael Haumann
- Institut für Physik Freie, Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Holger Dau
- Institut für Physik Freie, Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Peter Hildebrandt
- Institut für Chemie Technische, Universität Berlin, Fakultät II Straße des 17, Juni 135, 10623, Berlin, Germany
| | - Ulf-Peter Apfel
- Anorganische Chemie 1 Ruhr-Universität Bochum, Universitätsstraße 150, 44780, Bochum, Germany and Department of Electrosynthesis, Fraunhofer UMSICHT, Osterfelder Str. 3, 46047 Oberhausen, Germany
| | - Kallol Ray
- Institut für Chemie Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany.
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12
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Mubarak MQE, Gérard EF, Blanford CF, Hay S, de Visser SP. How Do Vanadium Chloroperoxidases Generate Hypochlorite from Hydrogen Peroxide and Chloride? A Computational Study. ACS Catal 2020. [DOI: 10.1021/acscatal.0c03490] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- M. Qadri E. Mubarak
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- Department of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Emilie F. Gérard
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- Department of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Christopher F. Blanford
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- Department of Materials, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Sam Hay
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Sam P. de Visser
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- Department of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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13
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Stanfield JK, Omura K, Matsumoto A, Kasai C, Sugimoto H, Shiro Y, Watanabe Y, Shoji O. Crystals in Minutes: Instant On-Site Microcrystallisation of Various Flavours of the CYP102A1 (P450BM3) Haem Domain. Angew Chem Int Ed Engl 2020; 59:7611-7618. [PMID: 32157795 DOI: 10.1002/anie.201913407] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/13/2019] [Indexed: 12/14/2022]
Abstract
Despite CYP102A1 (P450BM3) representing one of the most extensively researched metalloenzymes, crystallisation of its haem domain upon modification can be a challenge. Crystal structures are indispensable for the efficient structure-based design of P450BM3 as a biocatalyst. The abietane diterpenoid derivative N-abietoyl-l-tryptophan (AbiATrp) is an outstanding crystallisation accelerator for the wild-type P450BM3 haem domain, with visible crystals forming within 2 hours and diffracting to a near-atomic resolution of 1.22 Å. Using these crystals as seeds in a cross-microseeding approach, an assortment of P450BM3 haem domain crystal structures, containing previously uncrystallisable decoy molecules and diverse artificial metalloporphyrins binding various ligand molecules, as well as heavily tagged haem-domain variants, could be determined. Some of the structures reported herein could be used as models of different stages of the P450BM3 catalytic cycle.
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Affiliation(s)
- Joshua Kyle Stanfield
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Keita Omura
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Ayaka Matsumoto
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Chie Kasai
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Hiroshi Sugimoto
- RIKEN SPring-8 Centre, 1-1-1 Kouto, Sayo, Hyogo, 679-5148, Japan.,Core Research for Evolutional Science and Technology (Japan), Science and Technology Agency, 5 Sanbancho, Chiyoda-ku, Tokyo, 102-0075, Japan
| | - Yoshitsugu Shiro
- Graduate School of Life Science, University of Hyogo, 3-2-1-Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Yoshihito Watanabe
- Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-860, Japan
| | - Osami Shoji
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan.,Core Research for Evolutional Science and Technology (Japan), Science and Technology Agency, 5 Sanbancho, Chiyoda-ku, Tokyo, 102-0075, Japan
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14
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Stanfield JK, Omura K, Matsumoto A, Kasai C, Sugimoto H, Shiro Y, Watanabe Y, Shoji O. Kristalle in Minutenschnelle: Sofortige Mikrokristallisation verschiedenster Varianten der CYP102A1‐(P450BM3)‐Hämdomäne. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201913407] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Joshua Kyle Stanfield
- Department of Chemistry Graduate School of Science Nagoya University, Furo-cho, Chikusa-ku Nagoya 464-8602 Japan
| | - Keita Omura
- Department of Chemistry Graduate School of Science Nagoya University, Furo-cho, Chikusa-ku Nagoya 464-8602 Japan
| | - Ayaka Matsumoto
- Department of Chemistry Graduate School of Science Nagoya University, Furo-cho, Chikusa-ku Nagoya 464-8602 Japan
| | - Chie Kasai
- Department of Chemistry Graduate School of Science Nagoya University, Furo-cho, Chikusa-ku Nagoya 464-8602 Japan
| | - Hiroshi Sugimoto
- RIKEN SPring-8 Centre 1-1-1 Kouto Sayo Hyogo 679-5148 Japan
- Core Research for Evolutional Science and Technology (Japan) Science and Technology Agency 5 Sanbancho, Chiyoda-ku Tokyo 102-0075 Japan
| | - Yoshitsugu Shiro
- Graduate School of Life Science University of Hyogo 3-2-1-Kouto, Kamigori-cho Ako-gun Hyogo 678-1297 Japan
| | - Yoshihito Watanabe
- Research Center for Materials Science Nagoya University, Furo-cho, Chikusa-ku Nagoya 464-860 Japan
| | - Osami Shoji
- Department of Chemistry Graduate School of Science Nagoya University, Furo-cho, Chikusa-ku Nagoya 464-8602 Japan
- Core Research for Evolutional Science and Technology (Japan) Science and Technology Agency 5 Sanbancho, Chiyoda-ku Tokyo 102-0075 Japan
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15
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Lopez S, Mayes DM, Crouzy S, Cavazza C, Leprêtre C, Moreau Y, Burzlaff N, Marchi-Delapierre C, Ménage S. A Mechanistic Rationale Approach Revealed the Unexpected Chemoselectivity of an Artificial Ru-Dependent Oxidase: A Dual Experimental/Theoretical Approach. ACS Catal 2020. [DOI: 10.1021/acscatal.9b04904] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Sarah Lopez
- Univ. Grenoble-Alpes, CEA, CNRS, IRIG, CBM, F-38000 Grenoble, France
- Univ. Grenoble-Alpes, DCM-SeRCO, F-38000 Grenoble, France
| | | | - Serge Crouzy
- Univ. Grenoble-Alpes, CEA, CNRS, IRIG, CBM, F-38000 Grenoble, France
| | - Christine Cavazza
- Univ. Grenoble-Alpes, CEA, CNRS, IRIG, CBM, F-38000 Grenoble, France
| | - Chloé Leprêtre
- Univ. Grenoble-Alpes, CEA, CNRS, IRIG, CBM, F-38000 Grenoble, France
| | - Yohann Moreau
- Univ. Grenoble-Alpes, CEA, CNRS, IRIG, CBM, F-38000 Grenoble, France
| | - Nicolai Burzlaff
- Department of Chemistry and Pharmacy, Friedrich-Alexander-University of Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | | | - Stéphane Ménage
- Univ. Grenoble-Alpes, CEA, CNRS, IRIG, CBM, F-38000 Grenoble, France
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16
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Mubarak MQE, Visser SP. Computational Study on the Catalytic Reaction Mechanism of Heme Haloperoxidase Enzymes. Isr J Chem 2019. [DOI: 10.1002/ijch.201900099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- M. Qadri E. Mubarak
- Manchester Institute of Biotechnology and Department of Chemical Engineering and Analytical Science The University of Manchester 131 Princess Street Manchester M1 7DN United Kingdom
| | - Sam P. Visser
- Manchester Institute of Biotechnology and Department of Chemical Engineering and Analytical Science The University of Manchester 131 Princess Street Manchester M1 7DN United Kingdom
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17
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Hsu DJ, Leshchev D, Rimmerman D, Hong J, Kelley MS, Kosheleva I, Zhang X, Chen LX. X-ray snapshots reveal conformational influence on active site ligation during metalloprotein folding. Chem Sci 2019; 10:9788-9800. [PMID: 32055348 PMCID: PMC6993610 DOI: 10.1039/c9sc02630d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/01/2019] [Indexed: 12/20/2022] Open
Abstract
Cytochrome c (cyt c) has long been utilized as a model system to study metalloprotein folding dynamics and the interplay between active site ligation and tertiary structure. However, recent reports regarding the weakness of the native Fe(ii)-S bond (Fe-Met80) call into question the role of the active site ligation in the protein folding process. In order to investigate the interplay between protein conformation and active site structures, we directly tracked the evolution of both during a photolysis-induced folding reaction using X-ray transient absorption spectroscopy and time-resolved X-ray solution scattering techniques. We observe an intermediate Fe-Met80 species appearing on ∼2 μs timescale, which should not be sustained without stabilization from the folded protein structure. We also observe the appearance of a new active site intermediate: a weakly interacting Fe-H2O state. As both intermediates require stabilization of weak metal-ligand interactions, we surmise the existence of a local structure within the unfolded protein that protects and limits the movement of the ligands, similar to the entatic state found in the native cyt c fold. Furthermore, we observe that in some of the unfolded ensemble, the local stabilizing structure is lost, leading to expansion of the unfolded protein structure and misligation to His26/His33 residues.
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Affiliation(s)
- Darren J Hsu
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , USA .
| | - Denis Leshchev
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , USA .
| | - Dolev Rimmerman
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , USA .
| | - Jiyun Hong
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , USA .
| | - Matthew S Kelley
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , USA .
| | - Irina Kosheleva
- Center for Advanced Radiation Sources , The University of Chicago , Illinois 60637 , USA
| | - Xiaoyi Zhang
- X-ray Sciences Division of the Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , USA
| | - Lin X Chen
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , USA .
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18
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Timmins A, Quesne MG, Borowski T, de Visser SP. Group Transfer to an Aliphatic Bond: A Biomimetic Study Inspired by Nonheme Iron Halogenases. ACS Catal 2018. [DOI: 10.1021/acscatal.8b01673] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Amy Timmins
- The Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Matthew G. Quesne
- The Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Krakow, Poland
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, United Kingdom
| | - Tomasz Borowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Krakow, Poland
| | - Sam P. de Visser
- The Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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19
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A Comparative Review on the Catalytic Mechanism of Nonheme Iron Hydroxylases and Halogenases. Catalysts 2018. [DOI: 10.3390/catal8080314] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Enzymatic halogenation and haloperoxidation are unusual processes in biology; however, a range of halogenases and haloperoxidases exist that are able to transfer an aliphatic or aromatic C–H bond into C–Cl/C–Br. Haloperoxidases utilize hydrogen peroxide, and in a reaction with halides (Cl−/Br−), they react to form hypohalides (OCl−/OBr−) that subsequently react with substrate by halide transfer. There are three types of haloperoxidases, namely the iron-heme, nonheme vanadium, and flavin-dependent haloperoxidases that are reviewed here. In addition, there are the nonheme iron halogenases that show structural and functional similarity to the nonheme iron hydroxylases and form an iron(IV)-oxo active species from a reaction of molecular oxygen with α-ketoglutarate on an iron(II) center. They subsequently transfer a halide (Cl−/Br−) to an aliphatic C–H bond. We review the mechanism and function of nonheme iron halogenases and hydroxylases and show recent computational modelling studies of our group on the hectochlorin biosynthesis enzyme and prolyl-4-hydroxylase as examples of nonheme iron halogenases and hydroxylases. These studies have established the catalytic mechanism of these enzymes and show the importance of substrate and oxidant positioning on the stereo-, chemo- and regioselectivity of the reaction that takes place.
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20
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21
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Onoda H, Shoji O, Suzuki K, Sugimoto H, Shiro Y, Watanabe Y. α-Oxidative decarboxylation of fatty acids catalysed by cytochrome P450 peroxygenases yielding shorter-alkyl-chain fatty acids. Catal Sci Technol 2018. [DOI: 10.1039/c7cy02263h] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Shorter-alkyl-chain fatty acids such as tridecanoic acid or lauric acid were produced from myristic acid by CYP152 peroxygenases.
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Affiliation(s)
- Hiroki Onoda
- Department of Chemistry, Graduate School of Science
- Nagoya University
- Nagoya 464-0802
- Japan
| | - Osami Shoji
- Department of Chemistry, Graduate School of Science
- Nagoya University
- Nagoya 464-0802
- Japan
- Core Research for Evolutional Science and Technology (CREST)
| | - Kazuto Suzuki
- Department of Chemistry, Graduate School of Science
- Nagoya University
- Nagoya 464-0802
- Japan
| | - Hiroshi Sugimoto
- Core Research for Evolutional Science and Technology (CREST)
- Japan Science and Technology Agency
- Tokyo
- Japan
- RIKEN SPring-8 Center
| | | | - Yoshihito Watanabe
- Research Center for Materials Science
- Nagoya University
- Nagoya 464-0802
- Japan
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22
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23
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Suzuki K, Stanfield JK, Shoji O, Yanagisawa S, Sugimoto H, Shiro Y, Watanabe Y. Control of stereoselectivity of benzylic hydroxylation catalysed by wild-type cytochrome P450BM3 using decoy molecules. Catal Sci Technol 2017. [DOI: 10.1039/c7cy01130j] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The benzylic hydroxylation of non-native substrates was catalysed by cytochrome P450BM3, wherein “decoy molecules” controlled the stereoselectivity of the reactions.
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Affiliation(s)
- Kazuto Suzuki
- Department of Chemistry
- Graduate School of Science
- Nagoya University
- Nagoya 464-8602
- Japan
| | - Joshua Kyle Stanfield
- Department of Chemistry
- Graduate School of Science
- Nagoya University
- Nagoya 464-8602
- Japan
| | - Osami Shoji
- Department of Chemistry
- Graduate School of Science
- Nagoya University
- Nagoya 464-8602
- Japan
| | - Sota Yanagisawa
- Department of Chemistry
- Graduate School of Science
- Nagoya University
- Nagoya 464-8602
- Japan
| | - Hiroshi Sugimoto
- Core Research for Evolutional Science and Technology (CREST)
- Japan Science and Technology Agency
- Tokyo
- Japan
- RIKEN SPring-8 Center
| | | | - Yoshihito Watanabe
- Research Center for Materials Science
- Nagoya University
- Nagoya 464-8602
- Japan
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24
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Yosca TH, Langston MC, Krest CM, Onderko EL, Grove TL, Livada J, Green MT. Spectroscopic Investigations of Catalase Compound II: Characterization of an Iron(IV) Hydroxide Intermediate in a Non-thiolate-Ligated Heme Enzyme. J Am Chem Soc 2016; 138:16016-16023. [PMID: 27960340 PMCID: PMC5987761 DOI: 10.1021/jacs.6b09693] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report on the protonation state of Helicobacter pylori catalase compound II. UV/visible, Mössbauer, and X-ray absorption spectroscopies have been used to examine the intermediate from pH 5 to 14. We have determined that HPC-II exists in an iron(IV) hydroxide state up to pH 11. Above this pH, the iron(IV) hydroxide complex transitions to a new species (pKa = 13.1) with Mössbauer parameters that are indicative of an iron(IV)-oxo intermediate. Recently, we discussed a role for an elevated compound II pKa in diminishing the compound I reduction potential. This has the effect of shifting the thermodynamic landscape toward the two-electron chemistry that is critical for catalase function. In catalase, a diminished potential would increase the selectivity for peroxide disproportionation over off-pathway one-electron chemistry, reducing the buildup of the inactive compound II state and reducing the need for energetically expensive electron donor molecules.
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Affiliation(s)
- Timothy H. Yosca
- Departments of Chemistry & Molecular Biology and Biochemistry, University of California, Irvine, California 92697, United States
| | - Matthew C. Langston
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Courtney M. Krest
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Elizabeth L. Onderko
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Tyler L. Grove
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Jovan Livada
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Michael T. Green
- Departments of Chemistry & Molecular Biology and Biochemistry, University of California, Irvine, California 92697, United States
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25
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Huang X, Groves JT. Beyond ferryl-mediated hydroxylation: 40 years of the rebound mechanism and C-H activation. J Biol Inorg Chem 2016; 22:185-207. [PMID: 27909920 PMCID: PMC5350257 DOI: 10.1007/s00775-016-1414-3] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/03/2016] [Indexed: 11/24/2022]
Abstract
Since our initial report in 1976, the oxygen rebound mechanism has become the consensus mechanistic feature for an expanding variety of enzymatic C-H functionalization reactions and small molecule biomimetic catalysts. For both the biotransformations and models, an initial hydrogen atom abstraction from the substrate (R-H) by high-valent iron-oxo species (Fen=O) generates a substrate radical and a reduced iron hydroxide, [Fen-1-OH ·R]. This caged radical pair then evolves on a complicated energy landscape through a number of reaction pathways, such as oxygen rebound to form R-OH, rebound to a non-oxygen atom affording R-X, electron transfer of the incipient radical to yield a carbocation, R+, desaturation to form olefins, and radical cage escape. These various flavors of the rebound process, often in competition with each other, give rise to the wide range of C-H functionalization reactions performed by iron-containing oxygenases. In this review, we first recount the history of radical rebound mechanisms, their general features, and key intermediates involved. We will discuss in detail the factors that affect the behavior of the initial caged radical pair and the lifetimes of the incipient substrate radicals. Several representative examples of enzymatic C-H transformations are selected to illustrate how the behaviors of the radical pair [Fen-1-OH ·R] determine the eventual reaction outcome. Finally, we discuss the powerful potential of "radical rebound" processes as a general paradigm for developing novel C-H functionalization reactions with synthetic, biomimetic catalysts. We envision that new chemistry will continue to arise by bridging enzymatic "radical rebound" with synthetic organic chemistry.
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26
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A Practical Guide to High-resolution X-ray Spectroscopic Measurements and their Applications in Bioinorganic Chemistry. Isr J Chem 2016. [DOI: 10.1002/ijch.201600037] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Spectroscopic and QM/MM investigations of Chloroperoxidase catalyzed degradation of orange G. Arch Biochem Biophys 2016; 596:1-9. [DOI: 10.1016/j.abb.2016.02.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 02/05/2016] [Accepted: 02/24/2016] [Indexed: 11/30/2022]
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28
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Sengupta K, Chatterjee S, Dey A. Catalytic H2O2 Disproportionation and Electrocatalytic O2 Reduction by a Functional Mimic of Heme Catalase: Direct Observation of Compound 0 and Compound I in Situ. ACS Catal 2016. [DOI: 10.1021/acscatal.5b02668] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kushal Sengupta
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Sudipta Chatterjee
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Abhishek Dey
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
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29
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Oszajca M, Franke A, Brindell M, Stochel G, van Eldik R. Redox cycling in the activation of peroxides by iron porphyrin and manganese complexes. ‘Catching’ catalytic active intermediates. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2015.01.013] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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30
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Guo M, Sørensen LK, Delcey MG, Pinjari RV, Lundberg M. Simulations of iron K pre-edge X-ray absorption spectra using the restricted active space method. Phys Chem Chem Phys 2016; 18:3250-9. [DOI: 10.1039/c5cp07487h] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The intensities and relative energies of metal K pre-edge features are sensitive to both geometric and electronic structures.
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Affiliation(s)
- Meiyuan Guo
- Department of Chemistry-Ångström Laboratory
- Uppsala University
- SE-751 20 Uppsala
- Sweden
| | - Lasse Kragh Sørensen
- Department of Chemistry-Ångström Laboratory
- Uppsala University
- SE-751 20 Uppsala
- Sweden
| | - Mickaël G. Delcey
- Department of Chemistry-Ångström Laboratory
- Uppsala University
- SE-751 20 Uppsala
- Sweden
| | - Rahul V. Pinjari
- Department of Chemistry-Ångström Laboratory
- Uppsala University
- SE-751 20 Uppsala
- Sweden
| | - Marcus Lundberg
- Department of Chemistry-Ångström Laboratory
- Uppsala University
- SE-751 20 Uppsala
- Sweden
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31
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Beckwith MA, Ames W, Vila FD, Krewald V, Pantazis DA, Mantel C, Pécaut J, Gennari M, Duboc C, Collomb MN, Yano J, Rehr JJ, Neese F, DeBeer S. How Accurately Can Extended X-ray Absorption Spectra Be Predicted from First Principles? Implications for Modeling the Oxygen-Evolving Complex in Photosystem II. J Am Chem Soc 2015; 137:12815-34. [PMID: 26352328 DOI: 10.1021/jacs.5b00783] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
First principle calculations of extended X-ray absorption fine structure (EXAFS) data have seen widespread use in bioinorganic chemistry, perhaps most notably for modeling the Mn4Ca site in the oxygen evolving complex (OEC) of photosystem II (PSII). The logic implied by the calculations rests on the assumption that it is possible to a priori predict an accurate EXAFS spectrum provided that the underlying geometric structure is correct. The present study investigates the extent to which this is possible using state of the art EXAFS theory. The FEFF program is used to evaluate the ability of a multiple scattering-based approach to directly calculate the EXAFS spectrum of crystallographically defined model complexes. The results of these parameter free predictions are compared with the more traditional approach of fitting FEFF calculated spectra to experimental data. A series of seven crystallographically characterized Mn monomers and dimers is used as a test set. The largest deviations between the FEFF calculated EXAFS spectra and the experimental EXAFS spectra arise from the amplitudes. The amplitude errors result from a combination of errors in calculated S0(2) and Debye-Waller values as well as uncertainties in background subtraction. Additional errors may be attributed to structural parameters, particularly in cases where reliable high-resolution crystal structures are not available. Based on these investigations, the strengths and weaknesses of using first-principle EXAFS calculations as a predictive tool are discussed. We demonstrate that a range of DFT optimized structures of the OEC may all be considered consistent with experimental EXAFS data and that caution must be exercised when using EXAFS data to obtain topological arrangements of complex clusters.
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Affiliation(s)
- Martha A Beckwith
- Max Planck Institute for Chemical Energy Conversion , Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany.,Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - William Ames
- Max Planck Institute for Chemical Energy Conversion , Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Fernando D Vila
- Department of Physics, University of Washington , Seattle, Washington 98195, United States
| | - Vera Krewald
- Max Planck Institute for Chemical Energy Conversion , Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Dimitrios A Pantazis
- Max Planck Institute for Chemical Energy Conversion , Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Claire Mantel
- Département de Chimie Moléculaire, Université Joseph Fourier Grenoble, CNRS , F-38000 Grenoble, France
| | - Jacques Pécaut
- Laboratoire de Reconnaissance Ionique et Chimie de Coordination, Service de Chimie Inorganique et Biologique, (UMR E-3 CEA/UJF, FRE3200 CNRS), CEA-Grenoble, INAC , 17 rue des Martyrs 38054 Grenoble cedex 9, France
| | - Marcello Gennari
- Département de Chimie Moléculaire, Université Joseph Fourier Grenoble, CNRS , F-38000 Grenoble, France
| | - Carole Duboc
- Département de Chimie Moléculaire, Université Joseph Fourier Grenoble, CNRS , F-38000 Grenoble, France
| | - Marie-Noëlle Collomb
- Département de Chimie Moléculaire, Université Joseph Fourier Grenoble, CNRS , F-38000 Grenoble, France
| | - Junko Yano
- Physical Biosciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - John J Rehr
- Department of Physics, University of Washington , Seattle, Washington 98195, United States
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion , Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion , Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany.,Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
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32
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Significantly shorter Fe-S bond in cytochrome P450-I is consistent with greater reactivity relative to chloroperoxidase. Nat Chem 2015; 7:696-702. [PMID: 26291940 PMCID: PMC4580274 DOI: 10.1038/nchem.2306] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 06/19/2015] [Indexed: 11/16/2022]
Abstract
Cytochrome P450 (P450) and chloroperoxidase (CPO) are thiolate ligated heme proteins that catalyze the activation of carbon hydrogen bonds. The principal intermediate in these reactions is a ferryl radical species called compound I. P450 compound I (P450-I) is significantly more reactive than CPO-I, which only cleaves activated C-H bonds. To provide insight into the differing reactivities of these intermediates, we examined CPO-I and P450-I with variable temperature Mössbauer and X-ray absorption spectroscopies. These measurements indicate that the Fe-S bond is significantly shorter in P450-I than in CPO-I. This difference in Fe-S bond lengths can be understood in terms of variations in hydrogen bonding patterns within the “cys-pocket” (a portion of the proximal helix that encircles the thiolate ligand). Weaker hydrogen bonding in P450-I results in a shorter Fe-S bond, which enables greater electron donation from the axial-thiolate ligand. This observation may in part explain P450's greater propensity for C-H bond activation.
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33
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Enzymatic Halogenases and Haloperoxidases: Computational Studies on Mechanism and Function. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 100:113-51. [PMID: 26415843 DOI: 10.1016/bs.apcsb.2015.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Despite the fact that halogenated compounds are rare in biology, a number of organisms have developed processes to utilize halogens and in recent years, a string of enzymes have been identified that selectively insert halogen atoms into, for instance, a CH aliphatic bond. Thus, a number of natural products, including antibiotics, contain halogenated functional groups. This unusual process has great relevance to the chemical industry for stereoselective and regiospecific synthesis of haloalkanes. Currently, however, industry utilizes few applications of biological haloperoxidases and halogenases, but efforts are being worked on to understand their catalytic mechanism, so that their catalytic function can be upscaled. In this review, we summarize experimental and computational studies on the catalytic mechanism of a range of haloperoxidases and halogenases with structurally very different catalytic features and cofactors. This chapter gives an overview of heme-dependent haloperoxidases, nonheme vanadium-dependent haloperoxidases, and flavin adenine dinucleotide-dependent haloperoxidases. In addition, we discuss the S-adenosyl-l-methionine fluoridase and nonheme iron/α-ketoglutarate-dependent halogenases. In particular, computational efforts have been applied extensively for several of these haloperoxidases and halogenases and have given insight into the essential structural features that enable these enzymes to perform the unusual halogen atom transfer to substrates.
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Zhang Y, Biggs JD, Mukamel S. Characterizing the Intermediates Compound I and II in the Cytochrome P450 Catalytic Cycle with Nonlinear X-ray Spectroscopy: A Simulation Study. Chemphyschem 2015; 16:2006-14. [PMID: 25873009 DOI: 10.1002/cphc.201500064] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 02/24/2015] [Indexed: 11/06/2022]
Abstract
Cytochrome P450 enzymes are an important family of biocatalysts that oxidize chemically inert CH bonds. There are many unresolved questions regarding the catalytic reaction intermediates, in particular P450 Compound I (Cpd-I) and II (Cpd-II). By using simple molecular models, we simulate various X-ray spectroscopy signals, including X-ray absorption near-edge structure (XANES), resonant inelastic X-ray scattering (RIXS), and stimulated X-ray Raman spectroscopy (SXRS) of the low- and high-spin states of Cpd-I and II. Characteristic peak patterns are presented and connected to the corresponding electronic structures. These X-ray spectroscopy techniques are complementary to more conventional infrared and optical spectroscopy and they help to elucidate the evolving electronic structures of transient species along the reaction path.
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Affiliation(s)
- Yu Zhang
- Dept. of Chemistry, University of California, 450 Rowland Hall, Irvine, California 92697 (USA).
| | - Jason D Biggs
- Dept. of Chemistry, University of California, 450 Rowland Hall, Irvine, California 92697 (USA)
| | - Shaul Mukamel
- Dept. of Chemistry, University of California, 450 Rowland Hall, Irvine, California 92697 (USA).
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Viciano I, Castillo R, Martí S. QM/MM modeling of the hydroxylation of the androstenedione substrate catalyzed by cytochrome P450 aromatase (CYP19A1). J Comput Chem 2015; 36:1736-47. [DOI: 10.1002/jcc.23967] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 04/07/2015] [Accepted: 05/16/2015] [Indexed: 01/30/2023]
Affiliation(s)
- Ignacio Viciano
- Departament de Química Física i Analítica; Universitat Jaume I; Castelló 12071 Spain
| | - Raquel Castillo
- Departament de Química Física i Analítica; Universitat Jaume I; Castelló 12071 Spain
| | - Sergio Martí
- Departament de Química Física i Analítica; Universitat Jaume I; Castelló 12071 Spain
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Smith AT, Pazicni S, Marvin KA, Stevens DJ, Paulsen KM, Burstyn JN. Functional divergence of heme-thiolate proteins: a classification based on spectroscopic attributes. Chem Rev 2015; 115:2532-58. [PMID: 25763468 DOI: 10.1021/cr500056m] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Aaron T Smith
- †Department of Molecular Biosciences, Northwestern University, 2205 Tech Drive, Evanston, Illinois 60208, United States
| | - Samuel Pazicni
- ‡Department of Chemistry, University of New Hampshire, 23 Academic Way, Durham, New Hampshire 03824, United States
| | - Katherine A Marvin
- §Department of Chemistry, Hendrix College, 1600 Washington Avenue, Conway, Arkansas 72032, United States
| | - Daniel J Stevens
- ∥Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Katherine M Paulsen
- ∥Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Judith N Burstyn
- ∥Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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Viciano I, González-Navarrete P, Andrés J, Martí S. Joint Use of Bonding Evolution Theory and QM/MM Hybrid Method for Understanding the Hydrogen Abstraction Mechanism via Cytochrome P450 Aromatase. J Chem Theory Comput 2015; 11:1470-80. [DOI: 10.1021/ct501030q] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Ignacio Viciano
- Departament
de Química
Física i Analítica, Universitat Jaume I, 12071, Castellón, Spain
| | | | - Juan Andrés
- Departament
de Química
Física i Analítica, Universitat Jaume I, 12071, Castellón, Spain
| | - Sergio Martí
- Departament
de Química
Física i Analítica, Universitat Jaume I, 12071, Castellón, Spain
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Monooxygenase, peroxidase and peroxygenase properties and reaction mechanisms of cytochrome P450 enzymes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 851:1-61. [PMID: 26002730 DOI: 10.1007/978-3-319-16009-2_1] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review examines the monooxygenase, peroxidase and peroxygenase properties and reaction mechanisms of cytochrome P450 (CYP) enzymes in bacterial, archaeal and mammalian systems. CYP enzymes catalyze monooxygenation reactions by inserting one oxygen atom from O2 into an enormous number and variety of substrates. The catalytic versatility of CYP stems from its ability to functionalize unactivated carbon-hydrogen (C-H) bonds of substrates through monooxygenation. The oxidative prowess of CYP in catalyzing monooxygenation reactions is attributed primarily to a porphyrin π radical ferryl intermediate known as Compound I (CpdI) (Por•+FeIV=O), or its ferryl radical resonance form (FeIV-O•). CYP-mediated hydroxylations occur via a consensus H atom abstraction/oxygen rebound mechanism involving an initial abstraction by CpdI of a H atom from the substrate, generating a highly-reactive protonated Compound II (CpdII) intermediate (FeIV-OH) and a carbon-centered alkyl radical that rebounds onto the ferryl hydroxyl moiety to yield the hydroxylated substrate. CYP enzymes utilize hydroperoxides, peracids, perborate, percarbonate, periodate, chlorite, iodosobenzene and N-oxides as surrogate oxygen atom donors to oxygenate substrates via the shunt pathway in the absence of NAD(P)H/O2 and reduction-oxidation (redox) auxiliary proteins. It has been difficult to isolate the historically elusive CpdI intermediate in the native NAD(P)H/O2-supported monooxygenase pathway and to determine its precise electronic structure and kinetic and physicochemical properties because of its high reactivity, unstable nature (t½~2 ms) and short life cycle, prompting suggestions for participation in monooxygenation reactions of alternative CYP iron-oxygen intermediates such as the ferric-peroxo anion species (FeIII-OO-), ferric-hydroperoxo species (FeIII-OOH) and FeIII-(H2O2) complex.
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Structure and bonding analysis of intermediate model heme-imidazole and heme-thiolate enzymes complexed with formate, acetate and nitrate: A theoretical study. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2014.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Cui P, Wang Y, Chu W, Guo X, Yang F, Yu M, Zhao H, Dong Y, Xie Y, Gong W, Wu Z. How water molecules affect the catalytic activity of hydrolases--a XANES study of the local structures of peptide deformylase. Sci Rep 2014; 4:7453. [PMID: 25503313 PMCID: PMC4264029 DOI: 10.1038/srep07453] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 11/21/2014] [Indexed: 11/09/2022] Open
Abstract
Peptide deformylase (PDF) is a prokaryotic enzyme that catalyzes the deformylation of nascent peptides generated during protein synthesis and water molecules play a key role in these hydrolases. Using X-ray absorption near edge spectroscopy (XANES) and ab initio calculations we accurately probe the local atomic environment of the metal ion binding in the active site of PDF at different pH values and with different metal ions. This new approach is an effective way to monitor existing correlations among functions and structural changes. We show for the first time that the enzymatic activity depends on pH values and metal ions via the bond length of the nearest coordinating water (Wat1) to the metal ion. Combining experimental and theoretical data we may claim that PDF exhibits an enhanced enzymatic activity only when the distance of the Wat1 molecule with the metal ion falls in the limited range from 2.15 to 2.55 Å.
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Affiliation(s)
- Peixin Cui
- 1] National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China [2] Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Yu Wang
- Shanghai Synchrotron Radiation Facilities, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China
| | - Wangsheng Chu
- 1] National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China [2] Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Xiaoyun Guo
- 1] Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China [2] Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Feifei Yang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China
| | - Meijuan Yu
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Haifeng Zhao
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Yuhui Dong
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Yaning Xie
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Weimin Gong
- 1] Institute of Biophysics, Chinese Academy of Sciences, Beijing, China [2] Hefei National Laboratory for Physical Sciences at the microscale, University of Science and Technology of China
| | - Ziyu Wu
- 1] National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China [2] Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
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Yosca TH, Behan RK, Krest CM, Onderko EL, Langston MC, Green MT. Setting an upper limit on the myoglobin iron(IV)hydroxide pK(a): insight into axial ligand tuning in heme protein catalysis. J Am Chem Soc 2014; 136:9124-31. [PMID: 24875119 PMCID: PMC4091272 DOI: 10.1021/ja503588n] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To provide insight into the iron(IV)hydroxide pK(a) of histidine ligated heme proteins, we have probed the active site of myoglobin compound II over the pH range of 3.9-9.5, using EXAFS, Mössbauer, and resonance Raman spectroscopies. We find no indication of ferryl protonation over this pH range, allowing us to set an upper limit of 2.7 on the iron(IV)hydroxide pK(a) in myoglobin. Together with the recent determination of an iron(IV)hydroxide pK(a) ∼ 12 in the thiolate-ligated heme enzyme cytochrome P450, this result provides insight into Nature's ability to tune catalytic function through its choice of axial ligand.
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Affiliation(s)
- Timothy H Yosca
- Department of Chemistry, Pennsylvania State University , University Park, State College, Pennsylvania 16802, United States
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Cui P, Lian F, Wang Y, Wen Y, Chu W, Zhao H, Zhang S, Li J, Lin D, Wu Z. 3D local structure around copper site of rabbit prion-related protein: Quantitative determination by XANES spectroscopy combined with multiple-scattering calculations. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2013.01.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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43
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Gelalcha FG. Biomimetic Iron-Catalyzed Asymmetric Epoxidations: Fundamental Concepts, Challenges and Opportunities. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201300716] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Elenewski JE, Hackett JC. Cytochrome P450 compound I in the plane wave pseudopotential framework: GGA electronic and geometric structure of thiolate-ligated iron(IV)-oxo porphyrin. J Comput Chem 2013; 34:1647-60. [PMID: 23670855 PMCID: PMC3711018 DOI: 10.1002/jcc.23311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 03/18/2013] [Accepted: 04/07/2013] [Indexed: 11/11/2022]
Abstract
The cytochromes P450 constitute a ubiquitous family of metalloenzymes, catalyzing manifold reactions of biological and synthetic importance via a thiolate-ligated iron-oxo (IV) porphyrin radical species denoted compound I (Cpd I). Experimental investigations have implicated this intermediate in a broad spectrum of biophysically interesting phenomena, further augmenting the importance of a Cpd I model system. Ab initio molecular dynamics, including Car-Parrinello and path integral methods, conjoin electronic structure theory with finite temperature simulation, affording tools most valuable to approach such enzymes. These methods are typically driven by density functional theory (DFT) in a plane-wave pseudopotential framework; however, existing studies of Cpd I have been restricted to localized Gaussian basis sets. The appropriate choice of density functional and pseudopotential for such simulations is accordingly not obvious. To remedy this situation, a systematic benchmarking of thiolate-ligated Cpd I is performed using several generalized-gradient approximation (GGA) functionals in the Martins-Troullier and Vanderbilt ultrasoft pseudopotential schemes. The resultant electronic and structural parameters are compared to localized-basis DFT calculations using GGA and hybrid density functionals. The merits and demerits of each scheme are presented in the context of reproducing existing experimental and theoretical results for Cpd I.
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Affiliation(s)
- Justin E. Elenewski
- Goodwin Research Laboratory, Massey Cancer Center, Virginia Commonwealth University, 401 College Street, Richmond, Virginia 23219-1540
| | - John C Hackett
- Goodwin Research Laboratory, Massey Cancer Center, Virginia Commonwealth University, 401 College Street, Richmond, Virginia 23219-1540
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Zhang R, He Q, Chatfield D, Wang X. Paramagnetic nuclear magnetic resonance relaxation and molecular mechanics studies of the chloroperoxidase-indole complex: insights into the mechanism of chloroperoxidase-catalyzed regioselective oxidation of indole. Biochemistry 2013; 52:3688-701. [PMID: 23634952 DOI: 10.1021/bi4002437] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To unravel the mechanism of chloroperoxidase (CPO)-catalyzed regioselective oxidation of indole, we studied the structure of the CPO-indole complex using nuclear magnetic resonance (NMR) relaxation measurements and computational techniques. The dissociation constant (KD) of the CPO-indole complex was calculated to be approximately 21 mM. The distances (r) between protons of indole and the heme iron calculated via NMR relaxation measurements and molecular docking revealed that the pyrrole ring of indole is oriented toward the heme with its 2-H pointing directly at the heme iron. Both KD and r values are independent of pH in the range of 3.0-6.5. The stability and structure of the CPO-indole complex are also independent of the concentration of chloride or iodide ion. Molecular docking suggests the formation of a hydrogen bond between the NH group of indole and the carboxyl O of Glu 183 in the binding of indole to CPO. Simulated annealing of the CPO-indole complex using r values from NMR experiments as distance restraints reveals that the van der Waals interactions were much stronger than the Coulomb interactions in the binding of indole to CPO, indicating that the association of indole with CPO is primarily governed by hydrophobic rather than electrostatic interactions. This work provides the first experimental and theoretical evidence of the long-sought mechanism that leads to the "unexpected" regioselectivity of the CPO-catalyzed oxidation of indole. The structure of the CPO-indole complex will serve as a lighthouse in guiding the design of CPO mutants with tailor-made activities for biotechnological applications.
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Affiliation(s)
- Rui Zhang
- Department of Chemistry and Biochemistry, Florida International University , Miami, Florida 33199, United States
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Chandrasekaran P, Chiang KP, Nordlund D, Bergmann U, Holland PL, DeBeer S. Sensitivity of X-ray core spectroscopy to changes in metal ligation: a systematic study of low-coordinate, high-spin ferrous complexes. Inorg Chem 2013; 52:6286-98. [PMID: 23662855 DOI: 10.1021/ic3021723] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to assess the sensitivity and complementarity of X-ray absorption and emission spectroscopies for determining changes in the metal ligation sphere, a systematic experimental and theoretical study of iron model complexes has been carried out. A series of high-spin ferrous complexes, in which the ligation sphere has been varied from a three-coordinate complex, [L(tBu)Fe(SPh)] (1) (where L(tBu) = bulky β-diketiminate ligand; SPh = phenyl thiolate) to four-coordinate complexes [L(tBu)Fe(SPh)(X)] (where X = CN(t)Bu (2); 1-methylimidazole (3); or N,N-dimethylformamide (DMF) (4)), has been investigated using a combination of Fe K-edge X-ray absorption (XAS) and Kβ X-ray emission (XES) spectroscopies. The Fe K XAS pre-edge and edge of all four complexes are consistent with a high-spin ferrous assignment, with the largest differences in the pre-edge intensities attributed to changes in covalency of the fourth coordination site. The X-ray emission spectra show pronounced changes in the valence to core region (V2C) as the identity of the coordinated ligand is varied. The experimental results have been correlated to density functional theory (DFT) calculations, to understand key molecular orbital contributions to the observed absorption and emission features. The calculations also have been extended to a series of hypothetical high-spin iron complexes to understand the sensitivity of XAS and XES techniques to different ligand protonation states ([L(tBu)Fe(II)(SPh)(NHn)](3-n) (n = 3, 2, 1, 0)), metal oxidation states [L(tBu)Fe(SPh)(N)](n-) (n = 3, 2, 1), and changes in the ligand identity [L(tBu)Fe(IV)(SPh)(X)](n-) (X = C(4-), N(3-), O(2-); n = 2, 1, 0). This study demonstrates that XAS pre-edge data have greater sensitivity to changes in oxidation state, while valence to core (V2C) XES data provide a more sensitive probe of ligand identity and protonation state. The combination of multiple X-ray spectroscopic methods with DFT results thus has the potential to provide for detailed characterization of complex inorganic systems in both chemical and biological catalysis.
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Affiliation(s)
- P Chandrasekaran
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
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Viciano I, Berski S, Martí S, Andrés J. New insight into the electronic structure of iron(IV)-oxo porphyrin compound I. A quantum chemical topological analysis. J Comput Chem 2013; 34:780-9. [PMID: 23233452 DOI: 10.1002/jcc.23201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 09/06/2012] [Accepted: 11/15/2012] [Indexed: 11/11/2022]
Abstract
The electronic structure of iron-oxo porphyrin π-cation radical complex Por(·+) Fe(IV)=O (S-H) has been studied for doublet and quartet electronic states by means of two methods of the quantum chemical topology analysis: electron localization function (ELF) η(r) and electron density ρ(r). The formation of this complex leads to essential perturbation of the topological structure of the carbon-carbon bonds in porphyrin moiety. The double C=C bonds in the pyrrole anion subunits, represented by pair of bonding disynaptic basins V(i=1,2)(C,C) in isolated porphyrin, are replaced by single attractor V(C,C)(i=1-20) after complexation with the Fe cation. The iron-nitrogen bonds are covalent dative bonds, N→Fe, described by the disynaptic bonding basins V(Fe,N)(i=1-4), where electron density is almost formed by the lone pairs of the N atoms. The nature of the iron-oxygen bond predicted by the ELF topological analysis, shows a main contribution of the electrostatic interaction, Fe(δ+)···O(δ-), as long as no attractors between the C(Fe) and C(O) core basins were found, although there are common surfaces between the iron and oxygen basines and coupling between iron and oxygen lone pairs, that could be interpreted as a charge-shift bond. The Fe-S bond, characterized by the disynaptic bonding basin V(Fe,S), is partially a dative bond with the lone pair donated from sulfur atom. The change of electronic state from the doublet (M = 2) to quartet (M = 4) leads to reorganization of spin polarization, which is observed only for the porphyrin skeleton (-0.43e to 0.50e) and S-H bond (-0.55e to 0.52e).
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Affiliation(s)
- Ignacio Viciano
- Departamento de Química-Física y Analítica, Universitat Jaume I, 12071, Castelló, Spain
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Elenewski JE, Hackett JC. A GGA+U approach to effective electronic correlations in thiolate-ligated iron-oxo (IV) porphyrin. J Chem Phys 2013; 137:124311. [PMID: 23020335 DOI: 10.1063/1.4755290] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
High-valent oxo-metal complexes exhibit correlated electronic behavior on dense, low-lying electronic state manifolds, presenting challenging systems for electronic structure methods. Among these species, the iron-oxo (IV) porphyrin denoted Compound I occupies a privileged position, serving a broad spectrum of catalytic roles. The most reactive members of this family bear a thiolate axial ligand, exhibiting high activity toward molecular oxygen activation and substrate oxidation. The default approach to such systems has entailed the use of hybrid density functionals or multi-configurational/multireference methods to treat electronic correlation. An alternative approach is presented based on the GGA+U approximation to density functional theory, in which a generalized gradient approximation (GGA) functional is supplemented with a localization correction to treat on-site correlation as inspired by the Hubbard model. The electronic structure of thiolate-ligated iron-oxo (IV) porphyrin and corresponding Coulomb repulsion U are determined both empirically and self-consistently, yielding spin-distributions, state level splittings, and electronic densities of states consistent with prior hybrid functional calculations. Comparison of this detailed electronic structure with model Hamiltonian calculations suggests that the localized 3d iron moments induce correlation in the surrounding electron gas, strengthening local moment formation. This behavior is analogous to strongly correlated electronic systems such as Mott insulators, in which the GGA+U scheme serves as an effective single-particle representation for the full, correlated many-body problem.
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Affiliation(s)
- Justin E Elenewski
- Institute for Structural Biology and Drug Discovery and Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, 800 East Leigh Street, Richmond, Virginia 23219, USA
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