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Cao Y, Wu J, Zheng X, Lu Y, Piper JA, Lu Y, Packer NH. Assessing the activity of antibodies conjugated to upconversion nanoparticles for immunolabeling. Anal Chim Acta 2022; 1209:339863. [DOI: 10.1016/j.aca.2022.339863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/08/2022] [Accepted: 04/19/2022] [Indexed: 11/01/2022]
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Oshita H, Shimazaki Y. Recent Advances in One-Electron-Oxidized Cu II -Diphenoxide Complexes as Models of Galactose Oxidase: Importance of the Structural Flexibility in the Active Site. Chemistry 2020; 26:8324-8340. [PMID: 32056294 DOI: 10.1002/chem.201905877] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Indexed: 11/09/2022]
Abstract
The phenoxyl radical plays important roles in biological systems as cofactors in some metalloenzymes, such as galactose oxidase (GO) catalyzing oxidation of primary alcohols to give the corresponding aldehydes. Many metal(II)-phenoxyl radical complexes have hitherto been studied for understanding the detailed properties and reactivities of GO, and thus the nature of GO has gradually become clearer. However, the effects of the subtle geometric and electronic structural changes at the active site of GO, especially the structural change in the catalytic cycle and the effect of the second coordination sphere, have not been fully discussed yet. In this Review, we focus on further details of the model studies of GO and discuss the importance of the structural change at the active site of GO.
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Affiliation(s)
- Hiromi Oshita
- Faculty of Chemistry of Functional Molecules, Konan University, Higashinada-ku, Kobe, 658-8501, Japan
| | - Yuichi Shimazaki
- Graduate School of Science and Engineering, Ibaraki University, Bunkyo, Mito, 310-8512, Japan
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Sertçelik M, Özbek FE, Taslimi P, Durman M, Özdemir M, Yalçın B, Necefoğlu H, Hökelek T. Synthesis, spectroscopic characterization, crystal structure, density functional theory studies and biological properties of coordination complex Ni(II) 2‐fluorobenzoate with 3‐hydroxypyridine. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5802] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Mustafa Sertçelik
- Department of Chemical Engineering, Faculty of Engineering and ArchitectureKafkas University Kars 36300 Turkey
| | - Füreya Elif Özbek
- Department of Chemical Engineering, Faculty of Engineering and ArchitectureKafkas University Kars 36300 Turkey
| | - Parham Taslimi
- Department of Biotechnology, Faculty of ScienceBartin University Bartin 74100 Turkey
| | - Murat Durman
- Department of Physical Engineering, Faculty of EngineeringAnkara University Ankara 06100 Turkey
| | - Mücahit Özdemir
- Department of ChemistryMarmara University Kadikoy Istanbul 34722 Turkey
| | - Bahattin Yalçın
- Department of ChemistryMarmara University Kadikoy Istanbul 34722 Turkey
| | - Hacali Necefoğlu
- Department of Chemistry, Faculty of Sciences and ArtsKafkas University Kars 36300 Turkey
- International Scientific Research CentreBaku State University Baku 1148 Azerbaijan
| | - Tuncer Hökelek
- Department of PhysicsHacettepe University 06800 Beytepe Ankara Turkey
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Suzuki T, Oshita H, Yajima T, Tani F, Abe H, Shimazaki Y. Formation of the Cu II -Phenoxyl Radical by Reaction of O 2 with a Cu II -Phenolate Complex via the Cu I -Phenoxyl Radical. Chemistry 2019; 25:15805-15814. [PMID: 31486552 DOI: 10.1002/chem.201903077] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/11/2019] [Indexed: 01/13/2023]
Abstract
Reaction of Cu(ClO4 )2 ⋅6 H2 O with a tripodal 2N2O ligand, H2 Me2 NL, having a p-(dimethylamino)phenol moiety, in CH2 Cl2 /MeOH (1:1 v/v) under basic conditions under an inert gas atmosphere gave [Cu(Me2 NL)(H2 O)] (1). The same reaction carried out under aerobic conditions gave [Cu(Me2 NL)(MeOH)]ClO4 (2), which could be obtained also from the isolated complex 1 by reaction with O2 in CH2 Cl2 /MeOH. The X-ray crystal structures of 1 and 2 revealed similar square-pyramidal structures, but 2 showed the (dimethylamino)phenoxyl radical features. Complex 1 exhibits characteristic CuII EPR signals of the d x 2 - y 2 ground state in CH2 Cl2 /MeOH at 77 K, whereas 2 is EPR-silent. The EPR and X-ray absorption fine structure (XAFS) results suggest that 2 is assigned to the CuII -(dimethylamino)phenoxyl radical. However, complex 1 showed different features in the absence of MeOH. The EPR spectrum of the CH2 Cl2 solution of 1 exhibits distortion from the d x 2 - y 2 ground state and a temperature-dependent equilibrium between the CuII -(dimethylamino)phenolate and the CuI -(dimethylamino)phenoxyl radical. From these results, CuII -phenoxyl radical complex 2 is concluded to be formed by the reaction of 1 with O2 via the CuI -phenoxyl radical species.
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Affiliation(s)
- Takashi Suzuki
- Graduate School of Science and Engineering, Ibaraki University, Mito, 310-8512, Japan
| | - Hiromi Oshita
- Faculty of Chemistry of Functional Molecules, Konan University, Higashinada-ku, Kobe, 658-8501, Japan
| | - Tatsuo Yajima
- Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka, 564-8680, Japan
| | - Fumito Tani
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-Ku, Fukuoka, 819-0395, Japan
| | - Hitoshi Abe
- Institute of Materials Structure Science (IMSS), High Energy Accelerator Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan.,Department of Materials Structure Science, School of High Energy Accelerator Science, SOKENDAI (Graduate University for Advanced Studies), 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan
| | - Yuichi Shimazaki
- Graduate School of Science and Engineering, Ibaraki University, Mito, 310-8512, Japan
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Tóth EN, May NV, Rockenbauer A, Peintler G, Gyurcsik B. Exploring the boundaries of direct detection and characterization of labile isomers - a case study of copper(ii)-dipeptide systems. Dalton Trans 2017; 46:8157-8166. [PMID: 28607997 DOI: 10.1039/c7dt00884h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The investigation of the linkage isomers of biologically essential and kinetically labile metal complexes in aqueous solutions poses a challenge, as these microspecies cannot be separately studied. Therefore, derivatives are commonly used to initially determine the stability or spectral characteristics of at least one of the isomers. Here we directly detect the isomers, describe the metal ion coordination sphere, speciation and thermodynamic parameters by a synergistic application of temperature dependent EPR and CD spectroscopic measurements in copper(ii)-dipeptide systems including His-Gly and His-Ala ligands. The ΔH = (-23 ± 4) kJ mol-1 value of the standard enthalpy change corresponding to the peptide-type to histamine-type isomerisation equilibrium of the [CuL]+ complex was corroborated by several techniques. The preferential coordination of the side-chains was observed at lower temperatures, whereas, metal-binding of the backbone atoms became favourable upon increasing temperature. This study exemplifies the necessity of using temperature dependent multiple methodologies for a reliable description of similar systems for upstream applications.
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Affiliation(s)
- Eszter N Tóth
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary. and PhD Program in Human Biology, School of Integrative and Global Majors, University of Tsukuba, Japan
| | - Nóra V May
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary
| | - Antal Rockenbauer
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary and Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Spintronics Research Group (PROSPIN), P.O. Box 91, H-1521 Budapest, Hungary
| | - Gábor Peintler
- Department of Physical Chemistry and Material Sciences, University of Szeged, Aradi Vértanuk tere 1, H-6720 Szeged, Hungary
| | - Béla Gyurcsik
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary.
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Bhaumik PK, Chattopadhyay S. A novel polymeric copper(II) compound containing peripheral nitro oxygen bridge and μ-OH core: An unprecedented tetradentate bonding mode of a potentially tridentate Schiff base. INORG CHEM COMMUN 2012. [DOI: 10.1016/j.inoche.2012.05.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chiarella GM, Cotton FA, Dalal NS, Murillo CA, Wang Z, Young MD. Direct evidence from electron paramagnetic resonance for additional configurations in uncommon paddlewheel Re2(7+) units surrounded by an unsymmetrical bicyclic guanidinate. Inorg Chem 2012; 51:5257-63. [PMID: 22506487 DOI: 10.1021/ic300169f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Three rare compounds have been synthesized and structurally characterized; these species have paddlewheel structures and Re(2)(7+) cores surrounded by four bicyclic guanidinates and two axial ligands along the Re-Re axis. Each possesses a formal bond order of 3.5 and a σ(2)π(4)δ(1) electronic configuration that entails the presence of one unpaired electron for each compound. The guanidinate ligands characterized by having CH(2) entities and a central C(N)(3) unit that joins two cyclic units--one having two fused 6-membered rings (hpp) and the other having a 5- and a 6-membered ring fused together (tbn)--allowed the isolation of [Re(2)(tbn)(4)Cl(2)]PF(6), 1, [Re(2)(tbn)(4)Cl(2)]Cl, 2, and [Re(2)(hpp)(4)(O(3)SCF(3))(2)](O(3)SCF(3)), 3. Because of the larger bite angle of the tbn relative to the hpp ligand, the Re-Re bond distances in 1 and 2 (2.2691(14) and 2.2589(14) Å, respectively) are much longer than that in 3 (2.1804(8) Å). Importantly, electron paramagnetic resonance (EPR) studies at both X-band (~9.4 GHz) and W-band (112 GHz) in the solid and in frozen solution show unusually low g-values (~1.75) and the absence of zero-field splitting, providing direct evidence for the presence of one metal-based unpaired electron for both 1 and 3. These spectroscopic data suggest that the unsymmetrical 5-/6-membered ligand leads to the formation of isomers, as shown by significantly broader EPR signals for 1 than for 3, even though both compounds possess what appears to be similar ideal crystallographic axial symmetry on the X-ray time scale.
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Affiliation(s)
- Gina M Chiarella
- Department of Chemistry, Texas A&M University, P.O. Box 3012, College Station, Texas 77842-3012, USA
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Fainerman-Melnikova M, Clegg JK, Pakchung AAH, Jensen P, Codd R. Structural diversity of complexes between Cu(ii) or Ni(ii) and endocyclic oxygen- or nitrogen-containing ligands: synthesis, X-ray structure determinations and circular dichroism spectra. CrystEngComm 2010. [DOI: 10.1039/c0ce00323a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Price KA, Crouch PJ, Donnelly PS, Masters CL, White AR, Curtain CC. Membrane-targeted strategies for modulating APP and Abeta-mediated toxicity. J Cell Mol Med 2009; 13:249-61. [PMID: 19278455 PMCID: PMC3823352 DOI: 10.1111/j.1582-4934.2008.00642.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by numerous pathological features including the accumulation of neurotoxic amyloid-β (Aβ) peptide. There is currently no effective therapy for AD, but the development of therapeutic strategies that target the cell membrane is gaining increased interest. The amyloid precursor protein (APP) from which Aβ is formed is a membrane-bound protein, and Aβ production and toxicity are both membrane mediated events. This review describes the critical role of cell membranes in AD with particular emphasis on how the composition and structure of the membrane and its specialized regions may influence toxic or benign Aβ/APP pathways in AD. The putative role of copper (Cu) in AD is also discussed, and we highlight how targeting the cell membrane with Cu complexes has therapeutic potential in AD.
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Affiliation(s)
- Katherine A Price
- Department of Pathology, The University of Melbourne, Victoria, Australia.
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Hong JH, Duncan SE, O’Keefe SF, Dietrich AM. Ultrafiltration as a tool to study binding of copper to salivary proteins. Food Chem 2009. [DOI: 10.1016/j.foodchem.2008.07.065] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Šípoš R, Szabó-Plánka T, Rockenbauer A, Nagy NV, Šima J, Melník M, Nagypál I. Equilibria of 3-Pyridylmethanol with Copper(II). A Comparative Electron Spin Resonance Study by the Decomposition of Spectra in Liquid and Frozen Solutions. J Phys Chem A 2008; 112:10280-6. [DOI: 10.1021/jp805210v] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rastislav Šípoš
- Department of Inorganic Chemistry, Slovak Technical University, Bratislava, Slovakia, Department of Physical Chemistry, University of Szeged, Rerrich Béla tér 1, H-6720 Szeged, Hungary, and Chemical Research Center, Institute of Structural Chemistry, Hungarian Academy of Sciences, Budapest, Hungary
| | - Terézia Szabó-Plánka
- Department of Inorganic Chemistry, Slovak Technical University, Bratislava, Slovakia, Department of Physical Chemistry, University of Szeged, Rerrich Béla tér 1, H-6720 Szeged, Hungary, and Chemical Research Center, Institute of Structural Chemistry, Hungarian Academy of Sciences, Budapest, Hungary
| | - Antal Rockenbauer
- Department of Inorganic Chemistry, Slovak Technical University, Bratislava, Slovakia, Department of Physical Chemistry, University of Szeged, Rerrich Béla tér 1, H-6720 Szeged, Hungary, and Chemical Research Center, Institute of Structural Chemistry, Hungarian Academy of Sciences, Budapest, Hungary
| | - Nóra Veronika Nagy
- Department of Inorganic Chemistry, Slovak Technical University, Bratislava, Slovakia, Department of Physical Chemistry, University of Szeged, Rerrich Béla tér 1, H-6720 Szeged, Hungary, and Chemical Research Center, Institute of Structural Chemistry, Hungarian Academy of Sciences, Budapest, Hungary
| | - Jozef Šima
- Department of Inorganic Chemistry, Slovak Technical University, Bratislava, Slovakia, Department of Physical Chemistry, University of Szeged, Rerrich Béla tér 1, H-6720 Szeged, Hungary, and Chemical Research Center, Institute of Structural Chemistry, Hungarian Academy of Sciences, Budapest, Hungary
| | - Milan Melník
- Department of Inorganic Chemistry, Slovak Technical University, Bratislava, Slovakia, Department of Physical Chemistry, University of Szeged, Rerrich Béla tér 1, H-6720 Szeged, Hungary, and Chemical Research Center, Institute of Structural Chemistry, Hungarian Academy of Sciences, Budapest, Hungary
| | - István Nagypál
- Department of Inorganic Chemistry, Slovak Technical University, Bratislava, Slovakia, Department of Physical Chemistry, University of Szeged, Rerrich Béla tér 1, H-6720 Szeged, Hungary, and Chemical Research Center, Institute of Structural Chemistry, Hungarian Academy of Sciences, Budapest, Hungary
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