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Horn Jr. A, Englert D, Roberts AE, Comba P, Schenk G, Krenske EH, Gahan LR. Synthesis, Magnetic Properties, and Catalytic Properties of a Nickel(II)-Dependent Biomimetic of Metallohydrolases. Front Chem 2018; 6:441. [PMID: 30320072 PMCID: PMC6168013 DOI: 10.3389/fchem.2018.00441] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/05/2018] [Indexed: 11/13/2022] Open
Abstract
A dinickel(II) complex of the ligand 1,3-bis(bis(pyridin-2-ylmethyl)amino)propan-2-ol (HL1) has been prepared and characterized to generate a functional model for nickel(II) phosphoesterase enzymes. The complex, [Ni2(L1)(μ-OAc)(H2O)2](ClO4)2·H2O, was characterized by microanalysis, X-ray crystallography, UV-visible, and IR absorption spectroscopy and solid state magnetic susceptibility measurements. Susceptibility studies show that the complex is antiferromagnetically coupled with the best fit parameters J = -27.4 cm-1, g = 2.29, D = 28.4 cm-1, comparable to corresponding values measured for the analogous dicobalt(II) complex [Co2(L1)(μ-OAc)](ClO4)2·0.5 H2O (J = -14.9 cm-1 and g = 2.16). Catalytic measurements with the diNi(II) complex using the substrate bis(2,4-dinitrophenyl)phosphate (BDNPP) demonstrated activity toward hydrolysis of the phosphoester substrate with K m ~10 mM, and k cat ~0.025 s-1. The combination of structural and catalytic studies suggests that the likely mechanism involves a nucleophilic attack on the substrate by a terminal nucleophilic hydroxido moiety.
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Affiliation(s)
- Adolfo Horn Jr.
- Laboratório de Ciências Químicas, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Brazil
| | - Daniel Englert
- Anorganisch-Chemisches Institut and Interdisciplinary Center of Scientific Computing, Universität Heidelberg, Heidelberg, Germany
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Asha E. Roberts
- Anorganisch-Chemisches Institut and Interdisciplinary Center of Scientific Computing, Universität Heidelberg, Heidelberg, Germany
| | - Peter Comba
- Anorganisch-Chemisches Institut and Interdisciplinary Center of Scientific Computing, Universität Heidelberg, Heidelberg, Germany
| | - Gerhard Schenk
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Elizabeth H. Krenske
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Lawrence R. Gahan
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
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Massoud SS, Ledet CC, Junk T, Bosch S, Comba P, Herchel R, Hošek J, Trávníček Z, Fischer RC, Mautner FA. Dinuclear metal(ii)-acetato complexes based on bicompartmental 4-chlorophenolate: syntheses, structures, magnetic properties, DNA interactions and phosphodiester hydrolysis. Dalton Trans 2018; 45:12933-50. [PMID: 27479361 DOI: 10.1039/c6dt02596j] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A series of dinuclear metal(ii)-acetato complexes: [Ni2(μ-L(Cl)O)(μ2-OAc)2](PF6)·3H2O (1), [Ni2(μ-L(Cl)O)(μ2-OAc)2](ClO4)·CH3COCH3 (2), [Cu2(μ-L(Cl)O)(μ2-OAc)(ClO4)](ClO4) (3), [Cu2(μ-L(Cl)O)(OAc)2](PF6)·H2O (4), [Zn2(μ-L(Cl)O)(μ2-OAc)2](PF6) (5) and [Mn2(L(Cl)-O)(μ2-OAc)2](ClO4)·H2O (6), where L(Cl)O(-) = 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-chlorophenolate, were synthesized. The complexes were structurally characterized by spectroscopic techniques and single crystal X-ray crystallography. Six-coordinate geometries with doubly bridged acetato ligands were found in Ni(ii), Zn(ii) and Mn(ii) complexes 1, 2, 5 and 6, whereas with Cu(ii) complexes a five-coordinate species was obtained with 4, and mixed five- and six-coordinate geometries with a doubly bridged dimetal core were observed in 3. The magnetic properties of complexes 1-4 and 6 were studied at variable temperatures and revealed weak to very weak antiferromagnetic interactions in 1, 2, 4 and 6 (J = -0.55 to -9.4 cm(-1)) and ferromagnetic coupling in 3 (J = 15.4 cm(-1)). These results are consistent with DFT calculations performed at the B3LYP/def2-TZVP(-f) level of theory. Under physiological conditions, the interaction of the dinculear complexes 1-5 with supercoiled plasmid ds-DNA did not show any pronounced nuclease activity, but Ni(ii) complexes 1 and 2 revealed a strong ability to unwind the supercoiled conformation of ds-DNA. The mechanistic studies performed on the interaction of the Ni(ii) complexes with DNA demonstrated the important impact of the nickel(ii) ion in the unwinding process. In combination with the DNA study, the phosphatase activity of complexes 1, 3, and 5 was examined by the phosphodiester hydrolysis of bis(2,4-dinitrophenol)phosphate (BDNPP) in the pH range of 5.5-10.5 at 25 °C. The Michaelis-Menten kinetics performed at pH 7 and 10.7 showed that catalytic efficiencies kcat/KM (kcat = catalytic rate constant, KM = substrate binding constant) decrease in the order: Ni(ii), 1 > Zn(ii), 5 > Cu(ii), 3. A similar trend was also observed with the turnover numbers at pH = 7. The results are discussed in relation to the coordination geometry and nature of the metal center as well as the steric environment imposed by the compartmental phenoxido ligand.
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Affiliation(s)
- Salah S Massoud
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
| | - Catherine C Ledet
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
| | - Thomas Junk
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
| | - Simone Bosch
- Anorganisch-Chemisches Institut and Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Peter Comba
- Anorganisch-Chemisches Institut and Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Radovan Herchel
- Department of Inorganic Chemistry & Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, 17. listopadu 12, CZ-77146 Olomouc, Czech Republic.
| | - Jan Hošek
- Department of Inorganic Chemistry & Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, 17. listopadu 12, CZ-77146 Olomouc, Czech Republic.
| | - Zdeněk Trávníček
- Department of Inorganic Chemistry & Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, 17. listopadu 12, CZ-77146 Olomouc, Czech Republic.
| | - Roland C Fischer
- Institut für Anorganische Chemische, Technische Universität Graz, Stremayrgasse 9/V, A-8010 Graz, Austria
| | - Franz A Mautner
- Institut für Physikalische and Theoretische Chemie, Technische Universität Graz, Stremayrgasse 9/II, A-8010, Graz, Austria.
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Brown JJ, Gahan LR, Schöffler A, Krenske EH, Schenk G. Investigation of the identity of the nucleophile initiating the hydrolysis of phosphate esters catalyzed by dinuclear mimics of metallohydrolases. J Inorg Biochem 2016; 162:356-365. [DOI: 10.1016/j.jinorgbio.2016.02.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 01/17/2016] [Accepted: 02/10/2016] [Indexed: 11/17/2022]
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Massoud SS, Junk T, Louka FR, Herchel R, Trávníček Z, Fischer RC, Mautner FA. Synthesis, structure and magnetic characterization of dinuclear copper(ii) complexes bridged by bicompartmental phenolate. RSC Adv 2015. [DOI: 10.1039/c5ra19358c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Two series of bridged-phenoxido dinuclear Cu(ii) complexes were structurally and magnetically characterized: [Cu2(μ-LCl-O)(μ-X)](ClO4)2 (X = OH−, C3H3N2−, O2P(OC6H5)2−) and [Cu2(μ-LR-O)(X)2]PF6·2CH3CN (R = Cl, CH3 and X = dca) complexes.
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Affiliation(s)
- Salah S. Massoud
- Department of Chemistry
- University of Louisiana at Lafayette
- Lafayette
- USA
| | - Thomas Junk
- Department of Chemistry
- University of Louisiana at Lafayette
- Lafayette
- USA
| | - Febee R. Louka
- Department of Chemistry
- University of Louisiana at Lafayette
- Lafayette
- USA
| | - Radovan Herchel
- Department of Inorganic Chemistry & Regional Centre of Advanced Technologies and Materials
- Faculty of Science
- Palacký University
- CZ-77146 Olomouc
- Czech Republic
| | - Zdeněk Trávníček
- Department of Inorganic Chemistry & Regional Centre of Advanced Technologies and Materials
- Faculty of Science
- Palacký University
- CZ-77146 Olomouc
- Czech Republic
| | - Roland C. Fischer
- Institut für Anorganische Chemische
- Technische Universität Graz
- A-8010 Graz
- Austria
| | - Franz A. Mautner
- Institut für Physikalische and Theoretische Chemie
- Technische Universität Graz
- Graz
- Austria
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Massoud SS, Spell M, Ledet CC, Junk T, Herchel R, Fischer RC, Trávníček Z, Mautner FA. Magnetic and structural properties of dinuclear singly bridged-phenoxido metal(ii) complexes. Dalton Trans 2015; 44:2110-21. [DOI: 10.1039/c4dt03508a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Five new dinuclear bridged-phenoxido dichlorido-metal(ii) complexes [M2(μ-LClO)(X)2Cl2]PF6/ClO4 complexes, where M(ii) = Co, Ni, Cu (1–4) and Zn (5); X = CH3OH, H2O or 0 were synthesized and structurally characterized. Complexes 1–4 revealed weak to moderate antiferromagnetic coupling.
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Affiliation(s)
- Salah S. Massoud
- Department of Chemistry
- University of Louisiana at Lafayette
- Lafayette
- USA
| | - Mark Spell
- Department of Chemistry
- University of Louisiana at Lafayette
- Lafayette
- USA
| | | | - Thomas Junk
- Department of Chemistry
- University of Louisiana at Lafayette
- Lafayette
- USA
| | - Radovan Herchel
- Department of Inorganic Chemistry & Regional Centre of Advanced Technologies and Materials
- Faculty of Science
- Palacký University
- CZ-77146 Olomouc
- Czech Republic
| | - Roland C. Fischer
- Institut für Anorganische Chemische
- Technische Universität Graz
- A-8010 Graz
- Austria
| | - Zdeněk Trávníček
- Department of Inorganic Chemistry & Regional Centre of Advanced Technologies and Materials
- Faculty of Science
- Palacký University
- CZ-77146 Olomouc
- Czech Republic
| | - Franz A. Mautner
- Institut für Physikalische and Theoretische Chemie
- Technische Universität Graz
- Graz
- Austria
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Massoud SS, Junk T, Mikuriya M, Naka Y, Mautner FA. Synthesis, structure and magnetic characterization of dinuclear copper(II) complexes of 2,6-bis[bis(pyridine-2-ylmethyl)aminomethyl]-4-methylphenol. INORG CHEM COMMUN 2014. [DOI: 10.1016/j.inoche.2014.10.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Daumann LJ, Schenk G, Ollis DL, Gahan LR. Spectroscopic and mechanistic studies of dinuclear metallohydrolases and their biomimetic complexes. Dalton Trans 2013; 43:910-28. [PMID: 24135968 DOI: 10.1039/c3dt52287c] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An enhanced understanding of the metal ion binding and active site structural features of phosphoesterases such as the glycerophosphodiesterase from Enterobacter aerogenes (GpdQ), and the organophosphate degrading agent from Agrobacterium radiobacter (OpdA) have important consequences for potential applications. Coupled with investigations of the metalloenzymes, programs of study to synthesise and characterise model complexes based on these metalloenzymes can add to our understanding of structure and function of the enzymes themselves. This review summarises some of our work and illustrates the significance and contributions of model studies to knowledge in the area.
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Affiliation(s)
- Lena J Daumann
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
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