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Hossain MK, Köhntopp A, Haukka M, Richmond MG, Lehtonen A, Nordlander E. Cis- and trans molybdenum oxo complexes of a prochiral tetradentate aminophenolate ligand: Synthesis, characterization and oxotransfer activity. Polyhedron 2020. [DOI: 10.1016/j.poly.2019.114312] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Tyagi N, Chakraborty A, Singh UP, Roy P, Ghosh K. Mononuclear iron(iii) complexes of tridentate ligands with efficient nuclease activity and studies of their cytotoxicity. Org Biomol Chem 2015; 13:11445-58. [DOI: 10.1039/c5ob01623a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mono- and bis-chelated iron(iii) complexes derived from phenolato-based tridentate ligands have been synthesised and characterized. These complexes show electrostatic DNA interactions and efficient DNA cleavage via OH˙ radicals, and induce cytotoxicity in MCF7 cell lines.
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Affiliation(s)
- Nidhi Tyagi
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee-247667
- India
| | - Ajanta Chakraborty
- Department of Biochemistry
- Indian Institute of Technology Roorkee
- Roorkee-247667
- India
| | - Udai P. Singh
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee-247667
- India
| | - Partha Roy
- Department of Biochemistry
- Indian Institute of Technology Roorkee
- Roorkee-247667
- India
| | - Kaushik Ghosh
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee-247667
- India
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Dasgupta S, Atta S, Singh NDP, Deb D, Kassel WS, Bhattacharjee M. Synthesis and Structure of [Et
3
NH][Fe(HL)
2
] [H
3
L =
L
‐2‐(3,5‐Di‐
tert
‐butyl‐2‐hydroxybenzylamino)succinic Acid] and Its Catalytic Activity towards Efficient Photodegradation of Dyes in the Presence of H
2
O
2. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402314] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sohaham Dasgupta
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India http://www.chemistry.iitkgp.ac.in/faculty/NDPS/
| | - Sanghamitra Atta
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India http://www.chemistry.iitkgp.ac.in/faculty/NDPS/
| | - N. D. Pradeep Singh
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India http://www.chemistry.iitkgp.ac.in/faculty/NDPS/
| | - Dibakar Deb
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India http://www.chemistry.iitkgp.ac.in/faculty/NDPS/
| | - W. Scott Kassel
- Department of Chemistry, Villanova University, Villanova, PA 19085, USA
| | - Manish Bhattacharjee
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India http://www.chemistry.iitkgp.ac.in/faculty/NDPS/
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Bittner MM, Baus JS, Lindeman SV, Fiedler AT. Synthesis and Structural Characterization of Iron(II) Complexes with Tris(imidazolyl)phosphane Ligands: A Platform for Modeling the 3-Histidine Facial Triad of Nonheme Iron Dioxygenases. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201101282] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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6
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Singh R, Banerjee A, Rajak KK. Iron(III) complexes using NNS reduced Schiff bases and NNOS coordinating tetradentate ligands: Synthesis, structure and catecholase activity. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.05.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Mayilmurugan R, Sankaralingam M, Suresh E, Palaniandavar M. Novel square pyramidal iron(iii) complexes of linear tetradentate bis(phenolate) ligands as structural and reactive models for intradiol-cleaving 3,4-PCD enzymes: Quinone formation vs. intradiol cleavage. Dalton Trans 2010; 39:9611-25. [DOI: 10.1039/c0dt00171f] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Lapenna D, Ciofani G, Pierdomenico SD, Neri M, Cuccurullo C, Giamberardino MA, Cuccurullo F. Inhibitory activity of salicylic acid on lipoxygenase-dependent lipid peroxidation. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1790:25-30. [PMID: 18950686 DOI: 10.1016/j.bbagen.2008.09.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 09/03/2008] [Accepted: 09/22/2008] [Indexed: 11/30/2022]
Abstract
BACKGROUND Since iron is essential for lipoxygenase activity and salicylic acid (SA) can interact with the metal, possible lipoxygenase inhibition by SA was investigated. METHODS Kinetic spectrophotometric evaluation of enzymatic lipid peroxidation catalyzed by soybean lipoxygenase (SLO), rabbit reticulocyte 15-lipoxygenase (RR15-LOX), porcine leukocyte 12-lipoxygenase (PL12-LOX) and human recombinant 5-lipoxygenase (HR5-LOX) with and without SA. RESULTS SA inhibited linoleic, arachidonic and docosahexaenoic acid or human lipoprotein peroxidation catalyzed by SLO with IC50 of, respectively, 107, 153, 47 and 108 microM. Using the same substrates, SA inhibited RR15-LOX with IC50 of, respectively, 49, 63, 27 and 51 microM. Further, arachidonic acid peroxidation catalyzed by PL12-LOX and HR5-LOX was inhibited by SA with IC50 of 101 and 168 microM, respectively. Enzymatic inhibition was complete, reversible and non-competitive. Conceivably due to its lower hydrophobicity, aspirin was less effective, indicating acetylation-independent enzyme inhibition. SA and aspirin were ineffective peroxyl radical scavengers but readily reduced Fe3+, i.e. FeCl3, to Fe2+, suggesting their capacity to reduce Fe3+ at the enzyme active site. Indeed, similar to the catecholic redox inhibitor nordihydroguaiaretic acid, SA inhibited with the same efficiency both ferric and the native ferrous SLO form, indicating that these compounds reduce the active ferric enzyme leading to its inactivation. GENERAL SIGNIFICANCE SA can inhibit lipoxygenase-catalyzed lipid peroxidation at therapeutic concentrations, suggesting its possible inhibitory activity against enzymatic lipid peroxidation in the clinical setting.
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Affiliation(s)
- Domenico Lapenna
- Dipartimento di Medicina e Scienze dell'Invecchiamento, and Centro di Scienze dell'Invecchiamento-Fondazione Università G. d'Annunzio, Facoltà di Medicina e Chirurgia, 66100 Chieti, Italy.
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9
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Mayilmurugan R, Stoeckli-Evans H, Suresh E, Palaniandavar M. Chemoselective and biomimetic hydroxylation of hydrocarbons by non-heme μ-oxo-bridged diiron(iii) catalysts using m-CPBA as oxidant. Dalton Trans 2009:5101-14. [DOI: 10.1039/b820771b] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Matoga D, Szklarzewicz J, Stadnicka K, Shongwe MS. Iron(III) Complexes with a Biologically Relevant Aroylhydrazone: Crystallographic Evidence for Coordination Versatility. Inorg Chem 2007; 46:9042-4. [PMID: 17892285 DOI: 10.1021/ic701435x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Complexation of iron(III) with the heterodonor chelating agent 3,5-di-tert-butylsalicylidene benzoylhydrazine, H2(3,5-tBu2)salbh, in the absence or presence of a base affords the complex cation [Fe{H(3,5-tBu2)salbh}2]+ or the neutral compound [Fe{H(3,5-tBu2)salbh}{(3,5-tBu2)salbh}], respectively, as revealed by single-crystal X-ray analyses. Such a synthetic and crystallographic demonstration of the coordination versatility of an aroylhydrazone toward iron is uncommon. The oxidation and spin states of the iron have been verified with magnetic and spectroscopic measurements.
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Affiliation(s)
- Dariusz Matoga
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
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11
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Thapper A, Behrens A, Fryxelius J, Johansson MH, Prestopino F, Czaun M, Rehder D, Nordlander E. Synthesis and characterization of molybdenum oxo complexes of two tripodal ligands: reactivity studies of a functional model for molybdenum oxotransferases. Dalton Trans 2005:3566-71. [PMID: 16234939 DOI: 10.1039/b505180k] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Reaction of the tetradentate ligand N-(2-hydroxybenzyl)-N,N-bis(2-pyridylmethyl)amine (L-OH) with MoO2Cl2 in methanol in the presence of NaOMe and PF6- results in the formation of [MoO2(L-O)]PF6. Similarly, the reaction of N-(2-mercaptobenzyl)-N,N-bis(2-pyridylmethyl)amine (L-SH) with MoO2(acac)2 leads to the formation of [MoO2(L-S)]+. The dioxo-molybdenum complex [MoO2(L-O)]+ reacts with phosphines in methanol to afford phosphine oxides and an air-sensitive molybdenum complex, tentatively identified as [Mo(IV)O(L-O)(OCH3)]. The latter complex is capable of reducing biological oxygen donors such as DMSO or nitrate, thereby mimicking the activity of DMSO reductase and nitrate reductase. Reaction of [MoO2(L-O)]PF6 with PPh3 in other solvents than methanol leads to the formation of the Mo(V) dimer [(L-O)OMo(micro-O)MoO(L-O)](PF6)2. The crystal structures of [MoO2(L-O)]PF6 and the micro-oxo bridged dimer are presented.
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Affiliation(s)
- Anders Thapper
- Inorganic Chemistry, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00, Lund, Sweden
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12
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Velusamy M, Palaniandavar M, Gopalan RS, Kulkarni GU. Novel Iron(III) Complexes of Tripodal and Linear Tetradentate Bis(phenolate) Ligands: Close Relevance to Intradiol-Cleaving Catechol Dioxygenases. Inorg Chem 2003; 42:8283-93. [PMID: 14658880 DOI: 10.1021/ic020569w] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Four new iron(III) complexes of the bis(phenolate) ligands N,N-dimethyl-N',N'-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine [H2(L1)], N,N-dimethyl-N',N'-bis(2-hydroxy-4-nitrobenzyl)ethylenediamine [H2(L2)], N,N'-dimethyl-N,N'-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine [H2(L3)], and N,N'-dimethyl-N,N'-bis(2-hydroxy-4-nitrobenzyl)ethylenediamine [H2(L4)] have been isolated and studied as structural and functional models for the intradiol-cleaving catechol 1,2-dioxygenases (CTD). The complexes [Fe(L1)Cl] (1), [Fe(L2)(H2O)Cl] (2), [Fe(L3)Cl] (3), and [Fe(L4)(H2O)Cl] (4) have been characterized using absorption spectral and electrochemical techniques. The single-crystal X-ray structures of the ligand H2(L1) and the complexes 1 and 2 have been successfully determined. The tripodal ligand H2(L1) containing a N2O2 donor set represents the metal-binding region of the iron proteins. Complex 1 contains an FeN2O2Cl chromophore with a novel trigonal bipyramidal coordination geometry. While two phenolate oxygens and an amine nitrogen constitute the trigonal plane, the other amine nitrogen and chloride ion are located in the axial positions. In contrast, 2 exhibits a rhombically distorted octahedral coordination geometry for the FeN2O3Cl chromophore. Two phenolate oxygen atoms, an amine nitrogen atom, and a water molecule are located on the corners of a square plane with the axial positions being occupied by the other nitrogen atom and chloride ion. The interaction of the complexes with a few monodentate bases and phenolates and differently substituted catechols have been investigated using absorption spectral and electrochemical methods. The effect of substituents on the phenolate rings on the electronic spectral features and FeIII/FeII redox potentials of the complexes are discussed. The interaction of the complexes with catecholate anions reveals changes in the phenolate to iron(III) charge-transfer band and also the appearance of a low-energy catecholate to iron(III) charge-transfer band similar to catechol dioxygenase-substrate complexes. The redox behavior of the 1:1 adducts of the complexes with 3,5-di-tert-butylcatechol (H2DBC) has been also studied. The reactivities of the present complexes with H2DBC have been studied and illustrated. Interestingly, only 2 and 4 catalyze the intradiol-cleavage of H2DBC, the rate of oxygenation being much faster for 4. Also 2, but not 4, yields an extradiol cleavage product. The reactivity of the complexes could be illustrated not on the basis of the Lewis acidity of the complexes alone but by assuming that the product release is the rate-determining phase of the catalytic reaction.
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Affiliation(s)
- Marappan Velusamy
- Department of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, India
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13
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Higgs TC, Ji D, Czernuscewicz RS, Carrano CJ. Oxidation state dependent cis/trans isomerization in ML2 complexes of the heteroscorpionate ligand, (2-hydroxyphenyl)bis(pyrazolyl)methane and its derivatives with iron and cobalt. Inorganica Chim Acta 1999. [DOI: 10.1016/s0020-1693(98)00385-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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14
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Shah J, Klessig DF. Salicylic acid: signal perception and transduction. BIOCHEMISTRY AND MOLECULAR BIOLOGY OF PLANT HORMONES 1999. [DOI: 10.1016/s0167-7306(08)60503-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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15
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Dinger MB, Henderson W. Organogold(III) metallacyclic chemistry. Part 4. Synthesis, characterisation, and biological activity of gold(III)-thiosalicylate and -salicylate complexes. J Organomet Chem 1998. [DOI: 10.1016/s0022-328x(98)00493-8] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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16
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Viswanathan R, Palaniandavar M, Balasubramanian T, Muthiah TP. Functional Models for Catechol 1,2-Dioxygenase. Synthesis, Structure, Spectra, and Catalytic Activity of Certain Tripodal Iron(III) Complexes. Inorg Chem 1998. [DOI: 10.1021/ic970708n] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rathinam Viswanathan
- Department of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamilnadu, India
| | - Mallayan Palaniandavar
- Department of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamilnadu, India
| | | | - Thomas P. Muthiah
- Department of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamilnadu, India
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Loeb KE, Westre TE, Kappock TJ, Mitić N, Glasfeld E, Caradonna JP, Hedman B, Hodgson KO, Solomon EI. Spectroscopic Characterization of the Catalytically Competent Ferrous Site of the Resting, Activated, and Substrate-Bound Forms of Phenylalanine Hydroxylase. J Am Chem Soc 1997. [DOI: 10.1021/ja962269h] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kelly E. Loeb
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
| | - Tami E. Westre
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
| | - T. Joseph Kappock
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
| | - Nataša Mitić
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
| | - Elizabeth Glasfeld
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
| | - John P. Caradonna
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
| | - Britt Hedman
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
| | - Keith O. Hodgson
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
| | - Edward I. Solomon
- Contribution from the Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, and Department of Chemistry, Yale University, New Haven, Connecticut 06520
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Wang S, Wang L, Wang X, Luo Q. Synthesis, characterization and crystal structure of a new tripodal ligand containing imidazole and phenolate moieties and its iron(III) complexes. Inorganica Chim Acta 1997. [DOI: 10.1016/s0020-1693(96)05142-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Rapta M, Kamaras P, Jameson GB. Mononuclear precursor of heterodinuclear models for unsymmetrical active sites of metalloproteins: Synthesis and structure of dichloro (2-bis(2-benzimidazolylmethyl) aminomethyl-6-[(2-benzimidazoliummethyl)(2-methoxyphenylmethyl)aminiummethyl]-4-methyl-phenoxo-O, N, N′, N″) FeIII bis-perchlorate bis-ethanol solvate. Polyhedron 1996. [DOI: 10.1016/0277-5387(95)00461-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Abstract
It was demonstrated that salicylic acid (SA) not only binds to catalase from differentiated higher plants and plant cell suspension cultures but also to those of fungi and animals. SA bound specifically to iron-containing enzymes, such as catalase, aconitase, lipoxidase and peroxidase, while not to iron-free plant enzymes. On the grounds of these experiments, the claim is further challenged that SA is a signalling compound and second messenger in plants that activates plant defense-related genes through elevated H2O2 levels by specifically inhibiting catalase activity. SA may just function as a phytoalexin.
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Affiliation(s)
- M Rüffer
- Lehrstuhl für Pharmazeutische Biologie, Ludwig-Maximilians-Universität München, Germany
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21
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Ross DC, Egan TJ, Purves LR. Periodate modification of human serum transferrin Fe(III)-binding sites. Inhibition of carbonate insertion into Fe(III)- and Cu(II)-chelator-transferrin ternary complexes. J Biol Chem 1995; 270:12404-10. [PMID: 7759481 DOI: 10.1074/jbc.270.21.12404] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Periodate modification of human serum transferrin produces a species that binds Fe(III) weakly at pH 7.4 contrary to previous reports that Fe(III)-binding activity is completely lost. Ternary complexes of periodate-modified transferrin and either Fe(III) with nitrilotriacetate (NTA), oxalate, citrate, or EDTA, or of Cu(II) with oxalate could be formed. Peak wavelength maxima of these spectral bands are identical to those reported for native transferrin in the absence of bicarbonate. No carbonate ternary complexes of periodate-modified transferrin with Fe(III), Al(III), Cu(II), or Zn(II) could be formed. Conditional (Fe(NTA)) binding constants (log K) for C- and N-terminal modified sites are 7.33 and 7.54, respectively. The respective extinction coefficients at 470 nm are decreased 45% compared with the native protein. The electron paramagnetic resonance spectrum of the complex closely resembles that of the Fe(III)-NTA ternary complex formed with native transferrin in the absence of bicarbonate. Anions, including bicarbonate, at high concentrations destabilize formation of this Fe(III)-NTA ternary complex, while Fe(III) chelators readily remove the bound Fe(III). Bicarbonate, sulfate, and pyrophosphate still bind to the modified binding sites in the absence of metal although with slightly lower affinity and with lower molar difference absorptivities. Results are interpreted as an inhibition of a crucial protein conformational change by an intramolecular cross-link, preventing formation of the particularly stable metal-carbonate ternary complex from the less stable metal-chelate ternary complex. The method can be used to produce monosited transferrins.
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Affiliation(s)
- D C Ross
- Department of Chemical Pathology, University of Cape Town, Red Cross War Memorial Children's Hospital, Rondebosch, South Africa
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Jeffery JC, Moore CS, Psillakis E, Ward MD, Thornton P. The coordination chemistry of mixed pyridine-phenol and phenanthroline-phenol ligands; The crystal structure of 2-(2-hydroxyphenyl)-1,10-phenanthroline (HL) and the crystal structure and properties of [FeL2][PF6]. Polyhedron 1995. [DOI: 10.1016/0277-5387(94)00281-i] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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23
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Scarrow RC, Trimitsis MG, Buck CP, Grove GN, Cowling RA, Nelson MJ. X-ray spectroscopy of the iron site in soybean lipoxygenase-1: changes in coordination upon oxidation or addition of methanol. Biochemistry 1994; 33:15023-35. [PMID: 7999760 DOI: 10.1021/bi00254a011] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Iron K-edge X-ray spectroscopy (XANES and EXAFS) was used to study iron coordination in frozen solutions of soybean lipoxygenase-1 (SLO). The intensity of the 1s-->3d pre-edge transition of native iron(II) lipoxygenase is greater than what was found for six-coordinate high-spin iron(II) model complexes, but comparable to that of a five-coordinate model. This and a relatively short average bond length determined by EXAFS (2.13 A) indicate that the native lipoxygenase in our frozen samples is five-coordinate, excluding possible bonds longer than 2.5 A. The coordination of the iron(II) in native lipoxygenase changes when methanol (as low as 0.1%) or glycerol (20%) is added to the buffer prior to freezing. The addition of methanol diminishes the pre-edge transition and increases EXAFS-derived bond lengths by 0.04 A, indicating a change to six-coordination. The small pre-edge feature in active iron(III) lipoxygenase suggests six-coordination. EXAFS indicates a short, 1.88 A Fe-O bond, which, given other spectroscopic and crystallographic evidence, is assigned to coordinated hydroxide. The average of the remaining bond lengths is 2.11 A. The iron coordination in iron(III) lipoxygenase is less affected by the presence of alcohols than is the site in the iron(II) enzyme. Bond valence sums indicate that the bond lengths for lipoxygenase derived from our EXAFS analyses are comparable to those of crystallographically characterized model complexes. The flexibility of the coordination number in SLON (native SLO) and the presence of an [FeIIIOH]2+ unit in SLOA (active SLO) are of possible mechanistic importance.
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Affiliation(s)
- R C Scarrow
- Department of Chemistry, Haverford College, Pennsylvania 19041
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Powell AK, Heath SL. Polyiron(III) Oxyhydroxide Clusters: The Role of Iron(III) Hydrolysis and Mineralization in Nature. COMMENT INORG CHEM 1994. [DOI: 10.1080/02603599408035845] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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25
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Synthesis and characterization of a mononuclear iron(III) complex with a tripodal triamide ligand. Polyhedron 1993. [DOI: 10.1016/s0277-5387(00)84598-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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