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Miyagawa K, Isobe H, Shoji M, Kawakami T, Yamanaka S, Yamaguchi K. A three states model for hydrogen abstraction reactions with the cytochrome P450 compound I is revisited. Isolobal and isospin analogy among Fe(IV)=O, O = O and O. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2020.112902] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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2
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Yamaguchi K, Miyagawa K, Isobe H, Shoji M, Kawakami T, Yamanaka S. Isolobal and isospin analogy between organic and inorganic open-shell molecules—Application to oxygenation reactions by active oxygen and oxy-radicals and water oxidation in the native and artificial photosynthesis. ADVANCES IN QUANTUM CHEMISTRY 2021. [DOI: 10.1016/bs.aiq.2021.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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3
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Phung QM, Pierloot K. Low-Lying Electromeric States in Chloro-Ligated Iron(IV)-Oxo Porphyrin as a Model for Compound I, Studied with Second-Order Perturbation Theory Based on Density Matrix Renormalization Group. J Chem Theory Comput 2019; 15:3033-3043. [PMID: 30995039 DOI: 10.1021/acs.jctc.9b00166] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Employing second-order perturbation theory based on the density matrix renormalization group (DMRG-CASPT2), this work aims at providing a quantitative description of the spin state energetics of a chloro-ligated iron(IV)-oxo porphyrin as a model for the cytochromes P450 active species, also known as compound I (Cpd I). We explored DMRG-CASPT2 to its full extent with an extensive active space (up to 31 active orbitals) as well as a large number of renormalized states m (up to 10000). Different flavors of DMRG-CASPT2, using either the costly exact 4-particle reduced density matrix (4-RDM) or the cheaper cumulant approximated 4-RDM (cu(4)), were analyzed. All flavors essentially converge to similar relative energies between different spin states. Including a correction for the protein environment, we found a quartet FeIVO ground state and, more importantly, a thermally accessible doublet FeVO excited state that might directly contribute to the reactivity of this iron-oxo species. Our results also showed that cheaper approaches, such as CASPT2 based on a smaller active space or the cumulant approximation DMRG-cu(4)-CASPT2, are capable of accurately describing the spin state energetics of this species.
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Affiliation(s)
- Quan Manh Phung
- Department of Chemistry , KU Leuven , Celestijnenlaan 200F , Leuven 3001 , Belgium.,Institute of Transformative Bio-Molecules (WPI-ITbM) , Nagoya University , Chikusa, Nagoya 464-8602 , Japan
| | - Kristine Pierloot
- Department of Chemistry , KU Leuven , Celestijnenlaan 200F , Leuven 3001 , Belgium
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4
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Sheong F, Zhang JX, Lin Z. Revitalizing Spin Natural Orbital Analysis: Electronic Structures of Mixed-Valence Compounds, Singlet Biradicals, and Antiferromagnetically Coupled Systems. J Comput Chem 2019; 40:1172-1184. [PMID: 30652332 DOI: 10.1002/jcc.25762] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/20/2018] [Accepted: 11/09/2018] [Indexed: 12/20/2022]
Abstract
Chemical systems with open-shell electronic structure have been gaining attention these days. Their potential applications in first-row transition metal catalysis, molecular wires, photovoltaics and other potential applications have urged the adoption of a simple analysis tool to better understand their open-shell electronic structures, especially the role played by the unpaired electrons. Despite its lack of popularity, spin natural orbital (SNO) analysis is a tool we found to well-suit this purpose. We have therefore re-examined how the SNO could help us analyze some interesting open-shell systems, including mixed-valence compounds, singlet biradicals, and antiferromagnetically coupled systems. We found that some interesting patterns emerge from SNO analysis, especially those associated with exchange interaction. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- FuKit Sheong
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, People's Republic of China
| | - Jing-Xuan Zhang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, People's Republic of China
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, People's Republic of China
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5
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Yamaguchi K, Shoji M, Isobe H, Miyagawa K, Nakatani K. Theory of chemical bonds in metalloenzymes XXII: a concerted bond-switching mechanism for the oxygen–oxygen bond formation coupled with one electron transfer for water oxidation in the oxygen-evolving complex of photosystem II. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1552799] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- K. Yamaguchi
- Institute for Nanoscience Design, Osaka University, Toyonaka, Osaka, Japan
- The Institute for Scientific and Industrial Research, Osaka University, Osaka, Japan
- Handairigaku Techno-Research, Toyonaka, Osaka, Japan
| | - M. Shoji
- Center of Computational Sciences, Tsukuba University, Tsukuba, Ibaraki, Japan
| | - H. Isobe
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - K. Miyagawa
- The Institute for Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - K. Nakatani
- The Institute for Scientific and Industrial Research, Osaka University, Osaka, Japan
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6
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Shoji M, Isobe H, Shigeta Y, Nakajima T, Yamaguchi K. Nonadiabatic one-electron transfer mechanism for the O–O bond formation in the oxygen-evolving complex of photosystem II. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.02.056] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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7
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Yamaguchi K, Shoji M, Isobe H, Yamanaka S, Kawakami T, Yamada S, Katouda M, Nakajima T. Theory of chemical bonds in metalloenzymes XXI. Possible mechanisms of water oxidation in oxygen evolving complex of photosystem II. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1428375] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Kizashi Yamaguchi
- Institute for Nanoscience Design, Osaka University, Osaka, Japan
- Handairigaku Techno-Research, Osaka Univeristy, Osaka, Japan
- Riken Advanced Institute for Computational Science (AICS), Hyogo, Japan
| | - Mitsuo Shoji
- Center for Computational Sciences, University of Tsukuba, Ibaraki, Japan
| | - Hiroshi Isobe
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | | | - Takashi Kawakami
- Graduate School of Science, Osaka University, Osaka, Japan
- Riken Advanced Institute for Computational Science (AICS), Hyogo, Japan
| | - Satoru Yamada
- Riken Advanced Institute for Computational Science (AICS), Hyogo, Japan
| | - Michio Katouda
- Riken Advanced Institute for Computational Science (AICS), Hyogo, Japan
| | - Takahito Nakajima
- Riken Advanced Institute for Computational Science (AICS), Hyogo, Japan
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Pinter B, Chankisjijev A, Geerlings P, Harvey JN, De Proft F. Conceptual Insights into DFT Spin-State Energetics of Octahedral Transition-Metal Complexes through a Density Difference Analysis. Chemistry 2017; 24:5281-5292. [PMID: 29114944 DOI: 10.1002/chem.201704657] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Indexed: 11/08/2022]
Abstract
In this study, an intuitive concept is derived, which explains the characteristic dependence of spin-state energetics on the exact exchange admixture of DFT functionals in the case of octahedral transition metal complexes. The change in electron density distributions upon varying the admixture, c3 , in the B3LYP functional is analyzed for archetype ionic and covalent systems as well as for the Fe2+ ion in an ideal octahedral field. An understanding of how the DFT description of the electronic structure of octahedral complexes changes as a function of c3 is sought. A systematic spin-state energy analysis of 50 octahedral complexes of various metals and ligands with consistent experimental data is presented, allowing the derivation, in theory, of an optimal c3 value for each system. The notion that the admixture dependence of DFT spin-state energetics stems from the treatment of nondynamic electrons arising from the mixing of (M-Lz2 )0 (dz2 )2 and (M-Lx2-y2 )0 (dx2-y2 )2 configurations into the dominant (M-Lx2-y2 )2 (dx2-y2 )0 and (M-Lx2-y2 )2 (dx2-y2 )0 ones in the low(er) spin states is put forward. That is, in the effort to mimic such electron-electron interactions, ExLDA overestimates, whereas exact exchange downplays the contribution of this type of electron correlation to the stability of low(er) spin states, leading to the widespread practical observation that the higher the exact exchange admixture, the more stable the high-spin-state configuration.
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Affiliation(s)
- Balazs Pinter
- Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050, Brussels, Belgium
| | - Artiom Chankisjijev
- Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050, Brussels, Belgium
| | - Paul Geerlings
- Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050, Brussels, Belgium
| | - Jeremy N Harvey
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001, Leuven, Belgium
| | - Frank De Proft
- Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050, Brussels, Belgium
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9
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Davydov R, Im S, Shanmugam M, Gunderson WA, Pearl NM, Hoffman BM, Waskell L. Role of the Proximal Cysteine Hydrogen Bonding Interaction in Cytochrome P450 2B4 Studied by Cryoreduction, Electron Paramagnetic Resonance, and Electron-Nuclear Double Resonance Spectroscopy. Biochemistry 2016; 55:869-83. [PMID: 26750753 DOI: 10.1021/acs.biochem.5b00744] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Crystallographic studies have shown that the F429H mutation of cytochrome P450 2B4 introduces an H-bond between His429 and the proximal thiolate ligand, Cys436, without altering the protein fold but sharply decreases the enzymatic activity and stabilizes the oxyferrous P450 2B4 complex. To characterize the influence of this hydrogen bond on the states of the catalytic cycle, we have used radiolytic cryoreduction combined with electron paramagnetic resonance (EPR) and (electron-nuclear double resonance (ENDOR) spectroscopy to study and compare their characteristics for wild-type (WT) P450 2B4 and the F429H mutant. (i) The addition of an H-bond to the axial Cys436 thiolate significantly changes the EPR signals of both low-spin and high-spin heme-iron(III) and the hyperfine couplings of the heme-pyrrole (14)N but has relatively little effect on the (1)H ENDOR spectra of the water ligand in the six-coordinate low-spin ferriheme state. These changes indicate that the H-bond introduced between His and the proximal cysteine decreases the extent of S → Fe electron donation and weakens the Fe(III)-S bond. (ii) The added H-bond changes the primary product of cryoreduction of the Fe(II) enzyme, which is trapped in the conformation of the parent Fe(II) state. In the wild-type enzyme, the added electron localizes on the porphyrin, generating an S = (3)/2 state with the anion radical exchange-coupled to the Fe(II). In the mutant, it localizes on the iron, generating an S = (1)/2 Fe(I) state. (iii) The additional H-bond has little effect on g values and (1)H-(14)N hyperfine couplings of the cryogenerated, ferric hydroperoxo intermediate but noticeably slows its decay during cryoannealing. (iv) In both the WT and the mutant enzyme, this decay shows a significant solvent kinetic isotope effect, indicating that the decay reflects a proton-assisted conversion to Compound I (Cpd I). (v) We confirm that Cpd I formed during the annealing of the cryogenerated hydroperoxy intermediate and that it is the active hydroxylating species in both WT P450 2B4 and the F429H mutant. (vi) Our data also indicate that the added H-bond of the mutation diminishes the reactivity of Cpd I.
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Affiliation(s)
- Roman Davydov
- Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Sangchoul Im
- Department of Anesthesiology, University of Michigan, and VA Medical Center , 2215 Fuller Road, Ann Arbor, Michigan 48105, United States
| | - Muralidharan Shanmugam
- Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - William A Gunderson
- Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Naw May Pearl
- Department of Anesthesiology, University of Michigan, and VA Medical Center , 2215 Fuller Road, Ann Arbor, Michigan 48105, United States
| | - Brian M Hoffman
- Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Lucy Waskell
- Department of Anesthesiology, University of Michigan, and VA Medical Center , 2215 Fuller Road, Ann Arbor, Michigan 48105, United States
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10
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Mancini G, Zazza C. F429 Regulation of Tunnels in Cytochrome P450 2B4: A Top Down Study of Multiple Molecular Dynamics Simulations. PLoS One 2015; 10:e0137075. [PMID: 26415031 PMCID: PMC4587367 DOI: 10.1371/journal.pone.0137075] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 08/12/2015] [Indexed: 01/22/2023] Open
Abstract
The root causes of the outcomes of the single-site mutation in enzymes remain by and large not well understood. This is the case of the F429H mutant of the cytochrome P450 (CYP) 2B4 enzyme where the substitution, on the proximal surface of the active site, of a conserved phenylalanine 429 residue with histidine seems to hamper the formation of the active species, Compound I (porphyrin cation radical-Fe(IV) = O, Cpd I) from the ferric hydroperoxo (Fe(III)OOH-, Cpd 0) precursor. Here we report a study based on extensive molecular dynamic (MD) simulations of 4 CYP-2B4 point mutations compared to the WT enzyme, having the goal of better clarifying the importance of the proximal Phe429 residue on CYP 2B4 catalytic properties. To consolidate the huge amount of data coming from five simulations and extract the most distinct structural features of the five species studied we made an extensive use of cluster analysis. The results show that all studied single polymorphisms of F429, with different side chain properties: i) drastically alter the reservoir of conformations accessible by the protein, perturbing global dynamics ii) expose the thiolate group of residue Cys436 to the solvent, altering the electronic properties of Cpd0 and iii) affect the various ingress and egress channels connecting the distal sites with the bulk environment, altering the reversibility of these channels. In particular, it was observed that the wild type enzyme exhibits unique structural features as compared to all mutant species in terms of weak interactions (hydrogen bonds) that generate a completely different dynamical behavior of the complete system. Albeit not conclusive, the current computational investigation sheds some light on the subtle and critical effects that proximal single-site mutations can exert on the functional mechanisms of human microsomal CYPs which should go rather far beyond local structure characterization.
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Affiliation(s)
- Giordano Mancini
- Scuola Normale Superiore di Pisa, Piazza dei Cavalieri 7, 56126, Pisa, Italy, and Istituto Nazionale di Fisica Nucleare (INFN) sezione di Pisa, Largo Bruno Pontecorvo 3, 56127, Pisa, Italy
- * E-mail:
| | - Costantino Zazza
- Università degli Studi di Roma “La Sapienza”, Piazzale Aldo Moro 5, 00185, Roma, Italy
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11
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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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12
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Sainna MA, Kumar S, Kumar D, Fornarini S, Crestoni ME, de Visser SP. A comprehensive test set of epoxidation rate constants for iron(iv)-oxo porphyrin cation radical complexes. Chem Sci 2014; 6:1516-1529. [PMID: 29560240 PMCID: PMC5811088 DOI: 10.1039/c4sc02717e] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/08/2014] [Indexed: 12/31/2022] Open
Abstract
Trends in oxygen atom transfer to Compound I of the P450 models with an extensive test set have been studied and show a preferred regioselectivity of epoxidation over hydroxylation in the gas-phase for the first time.
Cytochrome P450 enzymes are heme based monoxygenases that catalyse a range of oxygen atom transfer reactions with various substrates, including aliphatic and aromatic hydroxylation as well as epoxidation reactions. The active species is short-lived and difficult to trap and characterize experimentally, moreover, it reacts in a regioselective manner with substrates leading to aliphatic hydroxylation and epoxidation products, but the origin of this regioselectivity is poorly understood. We have synthesized a model complex and studied it with low-pressure Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometry (MS). A novel approach was devised using the reaction of [FeIII(TPFPP)]+ (TPFPP = meso-tetrakis(pentafluorophenyl)porphinato dianion) with iodosylbenzene as a terminal oxidant which leads to the production of ions corresponding to [FeIV(O)(TPFPP+˙)]+. This species was isolated in the gas-phase and studied in its reactivity with a variety of olefins. Product patterns and rate constants under Ideal Gas conditions were determined by FT-ICR MS. All substrates react with [FeIV(O)(TPFPP+˙)]+ by a more or less efficient oxygen atom transfer process. In addition, substrates with low ionization energies react by a charge-transfer channel, which enabled us to determine the electron affinity of [FeIV(O)(TPFPP+˙)]+ for the first time. Interestingly, no hydrogen atom abstraction pathways are observed for the reaction of [FeIV(O)(TPFPP+˙)]+ with prototypical olefins such as propene, cyclohexene and cyclohexadiene and also no kinetic isotope effect in the reaction rate is found, which suggests that the competition between epoxidation and hydroxylation – in the gas-phase – is in favour of substrate epoxidation. This notion further implies that P450 enzymes will need to adapt their substrate binding pocket, in order to enable favourable aliphatic hydroxylation over double bond epoxidation pathways. The MS studies yield a large test-set of experimental reaction rates of iron(iv)–oxo porphyrin cation radical complexes, so far unprecedented in the gas-phase, providing a benchmark for calibration studies using computational techniques. Preliminary computational results presented here confirm the observed trends excellently and rationalize the reactivities within the framework of thermochemical considerations and valence bond schemes.
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Affiliation(s)
- Mala A Sainna
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science , The University of Manchester , 131 Princess Street , Manchester M1 7DN , UK .
| | - Suresh Kumar
- Department of Applied Physics , School for Physical Sciences , Babasaheb Bhimrao Ambedkar University , Vidya Vihar, Rai Bareilly Road , Lucknow 226 025 , India .
| | - Devesh Kumar
- Department of Applied Physics , School for Physical Sciences , Babasaheb Bhimrao Ambedkar University , Vidya Vihar, Rai Bareilly Road , Lucknow 226 025 , India .
| | - Simonetta Fornarini
- Dipartimento di Chimica e Tecnologie del Farmaco , Università di Roma "La Sapienza" , P.le A. Moro 5 , 00185 , Roma , Italy . ;
| | - Maria Elisa Crestoni
- Dipartimento di Chimica e Tecnologie del Farmaco , Università di Roma "La Sapienza" , P.le A. Moro 5 , 00185 , Roma , Italy . ;
| | - Sam P de Visser
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science , The University of Manchester , 131 Princess Street , Manchester M1 7DN , UK .
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Hirao H, Thellamurege N, Zhang X. Applications of density functional theory to iron-containing molecules of bioinorganic interest. Front Chem 2014; 2:14. [PMID: 24809043 PMCID: PMC4010748 DOI: 10.3389/fchem.2014.00014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 03/10/2014] [Indexed: 12/29/2022] Open
Abstract
The past decades have seen an explosive growth in the application of density functional theory (DFT) methods to molecular systems that are of interest in a variety of scientific fields. Owing to its balanced accuracy and efficiency, DFT plays particularly useful roles in the theoretical investigation of large molecules. Even for biological molecules such as proteins, DFT finds application in the form of, e.g., hybrid quantum mechanics and molecular mechanics (QM/MM), in which DFT may be used as a QM method to describe a higher prioritized region in the system, while a MM force field may be used to describe remaining atoms. Iron-containing molecules are particularly important targets of DFT calculations. From the viewpoint of chemistry, this is mainly because iron is abundant on earth, iron plays powerful (and often enigmatic) roles in enzyme catalysis, and iron thus has the great potential for biomimetic catalysis of chemically difficult transformations. In this paper, we present a brief overview of several recent applications of DFT to iron-containing non-heme synthetic complexes, heme-type cytochrome P450 enzymes, and non-heme iron enzymes, all of which are of particular interest in the field of bioinorganic chemistry. Emphasis will be placed on our own work.
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Affiliation(s)
- Hajime Hirao
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological UniversitySingapore, Singapore
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14
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Radoń M. Revisiting the role of exact exchange in DFT spin-state energetics of transition metal complexes. Phys Chem Chem Phys 2014; 16:14479-88. [DOI: 10.1039/c3cp55506b] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sensitivity of DFT spin-state energetics to exact exchange is rooted in the description of metal–ligand bonding.
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Affiliation(s)
- Mariusz Radoń
- Faculty of Chemistry
- Jagiellonian University in Kraków
- 30-060 Kraków, Poland
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15
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Kumar D, Latifi R, Kumar S, Rybak-Akimova EV, Sainna MA, de Visser SP. Rationalization of the Barrier Height for p-Z-styrene Epoxidation by Iron(IV)-Oxo Porphyrin Cation Radicals with Variable Axial Ligands. Inorg Chem 2013; 52:7968-79. [DOI: 10.1021/ic4005104] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Devesh Kumar
- Department of Applied Physics, School of Physical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar,
Rae Bareilly Road, Lucknow 226-025, India
| | - Reza Latifi
- Manchester Institute of Biotechnology and School
of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester M1 7DN,
U.K
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United
States
| | - Suresh Kumar
- Department of Applied Physics, School of Physical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar,
Rae Bareilly Road, Lucknow 226-025, India
| | | | - Mala A. Sainna
- Manchester Institute of Biotechnology and School
of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester M1 7DN,
U.K
| | - Sam P. de Visser
- Manchester Institute of Biotechnology and School
of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester M1 7DN,
U.K
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16
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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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17
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Similarities of artificial photosystems by ruthenium oxo complexes and native water splitting systems. Proc Natl Acad Sci U S A 2012; 109:15600-5. [PMID: 22761310 DOI: 10.1073/pnas.1120705109] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The nature of chemical bonds of ruthenium(Ru)-quinine(Q) complexes, mononuclear [Ru(trpy)(3,5-t-Bu(2)Q)(OH(2))](ClO(4))(2) (trpy = 2,2':6',2''-terpyridine, 3,5-di-tert-butyl-1,2-benzoquinone) (1), and binuclear [Ru(2)(btpyan)(3,6-di-Bu(2)Q)(2)(OH(2))](2+) (btpyan = 1,8-bis(2,2':6',2''-terpyrid-4'-yl)anthracene, 3,6-t-Bu(2)Q = 3,6-di-tert-butyl-1,2-benzoquinone) (2), has been investigated by broken-symmetry (BS) hybrid density functional (DFT) methods. BS DFT computations for the Ru complexes have elucidated that the closed-shell structure (2b) Ru(II)-Q complex is less stable than the open-shell structure (2bb) consisting of Ru(III) and semiquinone (SQ) radical fragments. These computations have also elucidated eight different electronic and spin structures of tetraradical intermediates that may be generated in the course of water splitting reaction. The Heisenberg spin Hamiltonian model for these species has been derived to elucidate six different effective exchange interactions (J) for four spin systems. Six J values have been determined using total energies of the eight (or seven) BS solutions for different spin configurations. The natural orbital analyses of these BS DFT solutions have also been performed in order to obtain natural orbitals and their occupation numbers, which are useful for the lucid understanding of the nature of chemical bonds of the Ru complexes. Implications of the computational results are discussed in relation to the proposed reaction mechanisms of water splitting reaction in artificial photosynthesis systems and the similarity between artificial and native water splitting systems.
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Isobe H, Yamaguchi K, Okumura M, Shimada J. Role of Perferryl–Oxo Oxidant in Alkane Hydroxylation Catalyzed by Cytochrome P450: A Hybrid Density Functional Study. J Phys Chem B 2012; 116:4713-30. [DOI: 10.1021/jp211184y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hiroshi Isobe
- Department of Chemistry, Graduate
School of Science, Osaka University, Toyonaka,
Osaka 560-0043, Japan
| | - Kizashi Yamaguchi
- Department of Chemistry, Graduate
School of Science, Osaka University, Toyonaka,
Osaka 560-0043, Japan
| | - Mitsutaka Okumura
- Department of Chemistry, Graduate
School of Science, Osaka University, Toyonaka,
Osaka 560-0043, Japan
| | - Jiro Shimada
- Green
Innovation Research Laboratories, NEC Corporation, 34, Miyukigaoka, Tsukuba, Ibaraki
305-8501, Japan
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Li C, Danovich D, Shaik S. Blended hydrogen atom abstraction and proton-coupled electron transfer mechanisms of closed-shell molecules. Chem Sci 2012. [DOI: 10.1039/c2sc20115a] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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