1
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Kumarage ND, Marts AR, Grindle MP, Kaine JC, Crandall LA, Chen WY, Ziegler CJ, Tierney DL. Field- and Temperature-Dependent Paramagnetic Relaxation Enhancements in Co(II) Trispyrazolylmethanes. Inorg Chem 2023; 62:15952-15962. [PMID: 37725578 DOI: 10.1021/acs.inorgchem.3c02028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
A comprehensive field- and temperature-dependent examination of nuclear magnetic resonance paramagnetic relaxation enhancements (PREs) for the constitutive protons of [Co(Tpm)2][BF4]2 is presented. Data for an apically substituted derivative clearly establish that bis-Tpm complexes of Co(II) undergo Jahn-Teller dynamics about the molecular threefold axis. PREs from the parent Tpm complex were used to numerically extract the electron relaxation times (T1e). The Tpm complex showed field-dependent behavior, with an approximately 40% higher activation barrier than the related trispyrazolylborate (Tp) complex, based on fits to the T1e vs T, B0 data. Analysis of the field-dependent line widths revealed a surprisingly large contribution from susceptibility (Curie) relaxation (20-35% at the highest field), and a molecular radius (9.5 Å) that is consistent with a tightly associated counterion slowing rotation in solution. Density functional theory showed a shared vibration that is consistent with the Jahn-Teller and appears proportionately higher in energy in [Co(Tpm)2]2+. Complete active-space self-consistent field calculations support ascribing electron relaxation to enhanced mixing of the two Eg orbital sets that accompanies the tetragonal distortion and the differences in electron correlation times to the higher Jahn-Teller activation barrier in [Co(Tpm)2]2+.
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Affiliation(s)
- Nuwanthika D Kumarage
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Amy R Marts
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Matthew P Grindle
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Joshua C Kaine
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Laura A Crandall
- Department of Chemistry, University of Akron, Akron, Ohio 44325, United States
| | - Wei-Yuan Chen
- Department of Chemistry, University of Akron, Akron, Ohio 44325, United States
| | | | - David L Tierney
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
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2
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Harriswangler C, Lucio-Martínez F, Godec L, Soro LK, Fernández-Fariña S, Valencia L, Rodríguez-Rodríguez A, Esteban-Gómez D, Charbonnière LJ, Platas-Iglesias C. Effect of Magnetic Anisotropy on the 1H NMR Paramagnetic Shifts and Relaxation Rates of Small Dysprosium(III) Complexes. Inorg Chem 2023; 62:14326-14338. [PMID: 37602400 PMCID: PMC10481378 DOI: 10.1021/acs.inorgchem.3c01959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Indexed: 08/22/2023]
Abstract
We present a detailed analysis of the 1H NMR chemical shifts and transverse relaxation rates of three small Dy(III) complexes having different symmetries (C3, D2 or C2). The complexes show sizeable emission in the visible region due to 4F9/2 → 6HJ transitions (J = 15/2 to 11/2). Additionally, NIR emission is observed at ca. 850 (4F9/2 → 6H7/2), 930 (4F9/2 → 6H5/2), 1010 (4F9/2 → 6F9/2), and 1175 nm (4F9/2 → 6F7/2). Emission quantum yields of 1-2% were determined in aqueous solutions. The emission lifetimes indicate that no water molecules are present in the inner coordination sphere of Dy(III), which in the case of [Dy(CB-TE2PA)]+ was confirmed through the X-ray crystal structure. The 1H NMR paramagnetic shifts induced by Dy(III) were found to be dominated by the pseudocontact mechanism, though, for some protons, contact shifts are not negligible. The analysis of the pseudocontact shifts provided the magnetic susceptibility tensors of the three complexes, which were also investigated using CASSCF calculations. The transverse 1H relaxation data follow a good linear correlation with 1/r6, where r is the distance between the Dy(III) ion and the observed proton. This indicates that magnetic anisotropy is not significantly affecting the relaxation of 1H nuclei in the family of complexes investigated here.
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Affiliation(s)
- Charlene Harriswangler
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Fátima Lucio-Martínez
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Léna Godec
- Equipe
de Synthèse Pour l′Analyse (SynPA), Institut Pluridisciplinaire
Hubert Curien (IPHC), UMR 7178, CNRS, Université
de Strasbourg, ECPM, 25 rue Becquerel, 67087 Strasbourg Cedex, France
| | - Lohona Kevin Soro
- Equipe
de Synthèse Pour l′Analyse (SynPA), Institut Pluridisciplinaire
Hubert Curien (IPHC), UMR 7178, CNRS, Université
de Strasbourg, ECPM, 25 rue Becquerel, 67087 Strasbourg Cedex, France
| | - Sandra Fernández-Fariña
- Departamento
de Química Inorgánica, Facultade de Química,
Campus Vida, Universidade de Santiago de
Compostela, 15782 Santiago de Compostela, Spain
| | - Laura Valencia
- Departamento
de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain
| | - Aurora Rodríguez-Rodríguez
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - David Esteban-Gómez
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Loïc J. Charbonnière
- Equipe
de Synthèse Pour l′Analyse (SynPA), Institut Pluridisciplinaire
Hubert Curien (IPHC), UMR 7178, CNRS, Université
de Strasbourg, ECPM, 25 rue Becquerel, 67087 Strasbourg Cedex, France
| | - Carlos Platas-Iglesias
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
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3
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Parigi G, Ravera E, Piccioli M, Luchinat C. Paramagnetic NMR restraints for the characterization of protein structural rearrangements. Curr Opin Struct Biol 2023; 80:102595. [PMID: 37075534 DOI: 10.1016/j.sbi.2023.102595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 04/21/2023]
Abstract
Mobility is a common feature of biomacromolecules, often fundamental for their function. Thus, in many cases, biomacromolecules cannot be described by a single conformation, but rather by a conformational ensemble. NMR paramagnetic data demonstrated quite informative to monitor this conformational variability, especially when used in conjunction with data from different sources. Due to their long-range nature, paramagnetic data can, for instance, i) clearly demonstrate the occurrence of conformational rearrangements, ii) reveal the presence of minor conformational states, sampled only for a short time, iii) indicate the most representative conformations within the conformational ensemble sampled by the molecule, iv) provide an upper limit to the weight of each conformation.
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Affiliation(s)
- Giacomo Parigi
- Magnetic Resonance Center (CERM), University of Florence, Via Sacconi 6, Sesto Fiorentino, 50019, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, Sesto Fiorentino, 50019, Italy; Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), Via Sacconi 6, Sesto Fiorentino, 50019, Italy.
| | - Enrico Ravera
- Magnetic Resonance Center (CERM), University of Florence, Via Sacconi 6, Sesto Fiorentino, 50019, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, Sesto Fiorentino, 50019, Italy; Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), Via Sacconi 6, Sesto Fiorentino, 50019, Italy
| | - Mario Piccioli
- Magnetic Resonance Center (CERM), University of Florence, Via Sacconi 6, Sesto Fiorentino, 50019, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, Sesto Fiorentino, 50019, Italy; Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), Via Sacconi 6, Sesto Fiorentino, 50019, Italy.
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM), University of Florence, Via Sacconi 6, Sesto Fiorentino, 50019, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, Sesto Fiorentino, 50019, Italy; Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), Via Sacconi 6, Sesto Fiorentino, 50019, Italy.
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4
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Zalewski M, Janasik D, Wierzbicka A, Krawczyk T. Design Principles of Responsive Relaxometric 19F Contrast Agents: Evaluation from the Point of View of Relaxation Theory and Experimental Data. Inorg Chem 2022; 61:19524-19542. [DOI: 10.1021/acs.inorgchem.2c03451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Mariusz Zalewski
- Department of Chemical Organic Technology and Petrochemistry, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 4, 44-100Gliwice, Poland
| | - Dawid Janasik
- Department of Chemical Organic Technology and Petrochemistry, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 4, 44-100Gliwice, Poland
| | - Adrianna Wierzbicka
- Department of Chemical Organic Technology and Petrochemistry, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 4, 44-100Gliwice, Poland
| | - Tomasz Krawczyk
- Department of Chemical Organic Technology and Petrochemistry, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 4, 44-100Gliwice, Poland
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5
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Ravera E, Gigli L, Fiorucci L, Luchinat C, Parigi G. The evolution of paramagnetic NMR as a tool in structural biology. Phys Chem Chem Phys 2022; 24:17397-17416. [PMID: 35849063 DOI: 10.1039/d2cp01838a] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Paramagnetic NMR data contain extremely accurate long-range information on metalloprotein structures and, when used in the frame of integrative structural biology approaches, they allow for the retrieval of structural details to a resolution that is not achievable using other techniques. Paramagnetic data thus represent an extremely powerful tool to refine protein models in solution, especially when coupled to X-ray or cryoelectron microscopy data, to monitor the formation of complexes and determine the relative arrangements of their components, and to highlight the presence of conformational heterogeneity. More recently, theoretical and computational advancements in quantum chemical calculations of paramagnetic NMR observables are progressively opening new routes in structural biology, because they allow for the determination of the structure within the coordination sphere of the metal center, thus acting as a loupe on sites that are difficult to observe but very important for protein function.
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Affiliation(s)
- Enrico Ravera
- Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.,Department of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, 50019, Italy.,Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.
| | - Lucia Gigli
- Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.,Department of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, 50019, Italy.,Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.
| | - Letizia Fiorucci
- Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.,Department of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, 50019, Italy.,Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.,Department of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, 50019, Italy.,Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.,Department of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, 50019, Italy.,Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy.
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6
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Miao Q, Nitsche C, Orton H, Overhand M, Otting G, Ubbink M. Paramagnetic Chemical Probes for Studying Biological Macromolecules. Chem Rev 2022; 122:9571-9642. [PMID: 35084831 PMCID: PMC9136935 DOI: 10.1021/acs.chemrev.1c00708] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Indexed: 12/11/2022]
Abstract
Paramagnetic chemical probes have been used in electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopy for more than four decades. Recent years witnessed a great increase in the variety of probes for the study of biological macromolecules (proteins, nucleic acids, and oligosaccharides). This Review aims to provide a comprehensive overview of the existing paramagnetic chemical probes, including chemical synthetic approaches, functional properties, and selected applications. Recent developments have seen, in particular, a rapid expansion of the range of lanthanoid probes with anisotropic magnetic susceptibilities for the generation of structural restraints based on residual dipolar couplings and pseudocontact shifts in solution and solid state NMR spectroscopy, mostly for protein studies. Also many new isotropic paramagnetic probes, suitable for NMR measurements of paramagnetic relaxation enhancements, as well as EPR spectroscopic studies (in particular double resonance techniques) have been developed and employed to investigate biological macromolecules. Notwithstanding the large number of reported probes, only few have found broad application and further development of probes for dedicated applications is foreseen.
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Affiliation(s)
- Qing Miao
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
- School
of Chemistry &Chemical Engineering, Shaanxi University of Science & Technology, Xi’an710021, China
| | - Christoph Nitsche
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Henry Orton
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
- ARC
Centre of Excellence for Innovations in Peptide & Protein Science,
Research School of Chemistry, Australian
National University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Mark Overhand
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Gottfried Otting
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
- ARC
Centre of Excellence for Innovations in Peptide & Protein Science,
Research School of Chemistry, Australian
National University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Marcellus Ubbink
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
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7
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Wilharm RK, Ramakrishnam Raju MV, Hoefler JC, Platas-Iglesias C, Pierre VC. Exploiting the Fluxionality of Lanthanide Complexes in the Design of Paramagnetic Fluorine Probes. Inorg Chem 2022; 61:4130-4142. [PMID: 35196450 PMCID: PMC8966431 DOI: 10.1021/acs.inorgchem.1c03908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Fluorine-19 MRI is increasingly being considered as a tool for biomolecular imaging, but the very poor sensitivity of this technique has limited most applications. Previous studies have long established that increasing the sensitivity of 19F molecular probes requires increasing the number of fluorine nuclei per probe as well as decreasing their longitudinal relaxation time. The latter is easily achieved by positioning the fluorine atoms in close proximity to a paramagnetic metal ion such as a lanthanide(III). Increasing the number of fluorine atoms per molecule, however, is only useful inasmuch as all of the fluorine nuclei are chemically equivalent. Previous attempts to achieve this equivalency have focused on designing highly symmetric and rigid fluorinated macrocyclic ligands. A much simpler approach consists of exploiting highly fluxional lanthanide complexes with open coordination sites that have a high affinity for phosphated and phosphonated species. Computational studies indicate that LnIII-TREN-MAM is highly fluxional, rapidly interconverting between at least six distinct isomers. In neutral water at room temperature, LnIII-TREN-MAM binds two or three equivalents of fluorinated phosphonates. The close proximity of the 19F nuclei to the LnIII center in the ternary complex decreases the relaxation times of the fluorine nuclei up to 40-fold. Advantageously, the fluorophosphonate-bound lanthanide complex is also highly fluxional such that all 19F nuclei are chemically equivalent and display a single 19F signal with a small LIS. Dynamic averaging of fluxional fluorinated supramolecular assemblies thus produces effective 19F MR systems.
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Affiliation(s)
- Randall K Wilharm
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | | | - John C Hoefler
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas and Departamento de Quıímica, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia Spain
| | - Valérie C Pierre
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Müntener T, Joss D, Häussinger D, Hiller S. Pseudocontact Shifts in Biomolecular NMR Spectroscopy. Chem Rev 2022; 122:9422-9467. [PMID: 35005884 DOI: 10.1021/acs.chemrev.1c00796] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Paramagnetic centers in biomolecules, such as specific metal ions that are bound to a protein, affect the nuclei in their surrounding in various ways. One of these effects is the pseudocontact shift (PCS), which leads to strong chemical shift perturbations of nuclear spins, with a remarkably long range of 50 Å and beyond. The PCS in solution NMR is an effect originating from the anisotropic part of the dipole-dipole interaction between the magnetic momentum of unpaired electrons and nuclear spins. The PCS contains spatial information that can be exploited in multiple ways to characterize structure, function, and dynamics of biomacromolecules. It can be used to refine structures, magnify effects of dynamics, help resonance assignments, allows for an intermolecular positioning system, and gives structural information in sensitivity-limited situations where all other methods fail. Here, we review applications of the PCS in biomolecular solution NMR spectroscopy, starting from early works on natural metalloproteins, following the development of non-natural tags to chelate and attach lanthanoid ions to any biomolecular target to advanced applications on large biomolecular complexes and inside living cells. We thus hope to not only highlight past applications but also shed light on the tremendous potential the PCS has in structural biology.
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Affiliation(s)
- Thomas Müntener
- Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland
| | - Daniel Joss
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Daniel Häussinger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Sebastian Hiller
- Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland
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Santana FS, Perfetti M, Briganti M, Sacco F, Poneti G, Ravera E, Soares JF, Sessoli R. A dysprosium single molecule magnet outperforming current pseudocontact shift agents. Chem Sci 2022; 13:5860-5871. [PMID: 35685802 PMCID: PMC9132026 DOI: 10.1039/d2sc01619b] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/26/2022] [Indexed: 12/19/2022] Open
Abstract
A common criterion for designing performant single molecule magnets and pseudocontact shift tags is a large magnetic anisotropy. In this article we present a dysprosium complex chemically designed to exhibit strong easy-axis type magnetic anisotropy that is preserved in dichloromethane solution at room temperature. Our detailed theoretical and experimental studies on the magnetic properties allowed explaining several features typical of highly performant SMMs. Moreover, the NMR characterization shows remarkably large chemical shifts, outperforming the current state-of-the art PCS tags. A robust dysprosium(iii) single molecule magnet with large uniaxial magnetic anisotropy induces pseudocontact shifts at almost doubled distance compared to standard shift agents.![]()
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Affiliation(s)
- Francielli S. Santana
- Departamento de Química, Universidade Federal do Paraná, Centro Politécnico, 81530-900 Curitiba, PR, Brazil
| | - Mauro Perfetti
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019, Italy
- Research Unit Firenze, INSTM, I-50019 Sesto Fiorentino, Firenze, Italy
| | - Matteo Briganti
- Departamento de Química, Universidade Federal do Paraná, Centro Politécnico, 81530-900 Curitiba, PR, Brazil
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019, Italy
| | - Francesca Sacco
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019, Italy
- Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy
- Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine, Via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy
| | - Giordano Poneti
- Instituto de Química, Universidade Federal do Rio de Janeiro, Centro de Tecnologia – Cidade Universitária, Avenida Athos da Silveira Ramos, 149, 21941-909 Rio de Janeiro, Brazil
| | - Enrico Ravera
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019, Italy
- Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy
- Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine, Via Luigi Sacconi 6, Sesto Fiorentino, 50019, Italy
| | - Jaísa F. Soares
- Departamento de Química, Universidade Federal do Paraná, Centro Politécnico, 81530-900 Curitiba, PR, Brazil
| | - Roberta Sessoli
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019, Italy
- Research Unit Firenze, INSTM, I-50019 Sesto Fiorentino, Firenze, Italy
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10
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Indris S, Bredow T, Schwarz B, Eichhöfer A. Paramagnetic 7Li NMR Shifts and Magnetic Properties of Divalent Transition Metal Silylamide Ate Complexes [LiM{N(SiMe 3) 2} 3] (M 2+ = Mn, Fe, Co). Inorg Chem 2021; 61:554-567. [PMID: 34931842 DOI: 10.1021/acs.inorgchem.1c03237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
7Li NMR shifts and magnetic properties have been determined for three so-called ate complexes [LiM{N(SiMe3)2}3] (M2+ = Mn, Fe, Co; e.g., named lithium-tris(bis(trimethylsilylamide))-manganate(II) in accordance with a formally negative charge assigned to the complex fragment [M{N(SiMe3)2}3]-, which comprises the transition metal). They are formed by addition reactions of LiN(SiMe3)2 and [M{N(SiMe3)2}2] and stabilized by Lewis base/Lewis acid interactions. The results are compared to those of the related "ion-separated" complexes [Li(15-crown-5)][M{N(SiMe3)2}3]. The ate complexes with the lithium atoms connected to the 3d metal atoms manganese, iron, or cobalt via μ2 nitrogen bridges reveal strong 7Li NMR paramagnetic shifts of about -75, 125, and 171 ppm, respectively, whereas the shifts for the lithium ions coordinated by the 15-crown-5 ether are close to zero. The observed trends of the 7Li NMR shifts are confirmed by density-functional theory calculations. The magnetic dc and ac properties display distinct differences for the six compounds under investigation. Both manganese compounds, [LiMn{N(SiMe3)2}3] and [Li(15-crown-5)][Mn{N(SiMe3)2}3], display almost pure and ideal spin-only paramagnetic behavior of a 3d5 high-spin complex. In this respect slightly unexpected, both complexes show slow relaxation behavior at low temperatures under applied dc fields, which is especially pronounced for the ate complex [LiMn{N(SiMe3)2}3]. Dc magnetic properties of the iron complexes reveal moderate g-factor anisotropies with small values of the axial magnetic anisotropy parameter D and a larger E (transversal anisotropy). Both complexes display at low temperatures and, under external dc fields of up to 5000 Oe, only weak ac signals with no maxima in the frequency range from 1 to 1500 s-1. In contrast, the two cobalt complexes display strong g-factor anisotropies with large values of D and E. In addition, in both cases, the ac measurements at low temperatures and applied dc fields reveal two, in terms of their frequency range, well separated relaxation processes with maxima lying for the most part outside of the measurement range between 1 and 1500 s-1.
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Affiliation(s)
- Sylvio Indris
- Institute for Applied Materials - Energy Storage Systems (IAM-ESS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Thomas Bredow
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraße 4, 53115 Bonn, Germany
| | - Björn Schwarz
- Institute for Applied Materials - Energy Storage Systems (IAM-ESS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Andreas Eichhöfer
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Campus Nord, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.,Karlsruhe Nano Micro Facility (KNMF), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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11
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Venu AC, Nasser Din R, Rudszuck T, Picchetti P, Chakraborty P, Powell AK, Krämer S, Guthausen G, Ibrahim M. NMR Relaxivities of Paramagnetic Lanthanide-Containing Polyoxometalates. Molecules 2021; 26:7481. [PMID: 34946561 PMCID: PMC8703889 DOI: 10.3390/molecules26247481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 11/16/2022] Open
Abstract
The current trend for ultra-high-field magnetic resonance imaging (MRI) technologies opens up new routes in clinical diagnostic imaging as well as in material imaging applications. MRI selectivity is further improved by using contrast agents (CAs), which enhance the image contrast and improve specificity by the paramagnetic relaxation enhancement (PRE) mechanism. Generally, the efficacy of a CA at a given magnetic field is measured by its longitudinal and transverse relaxivities r1 and r2, i.e., the longitudinal and transverse relaxation rates T1-1 and T2-1 normalized to CA concentration. However, even though basic NMR sensitivity and resolution become better in stronger fields, r1 of classic CA generally decreases, which often causes a reduction of the image contrast. In this regard, there is a growing interest in the development of new contrast agents that would be suitable to work at higher magnetic fields. One of the strategies to increase imaging contrast at high magnetic field is to inspect other paramagnetic ions than the commonly used Gd(III)-based CAs. For lanthanides, the magnetic moment can be higher than that of the isotropic Gd(III) ion. In addition, the symmetry of electronic ground state influences the PRE properties of a compound apart from diverse correlation times. In this work, PRE of water 1H has been investigated over a wide range of magnetic fields for aqueous solutions of the lanthanide containing polyoxometalates [DyIII(H2O)4GeW11O39]5- (Dy-W11), [ErIII(H2O)3GeW11O39]5- (Er-W11) and [{ErIII(H2O)(CH3COO)(P2W17O61)}2]16- (Er2-W34) over a wide range of frequencies from 20 MHz to 1.4 GHz. Their relaxivities r1 and r2 increase with increasing applied fields. These results indicate that the three chosen POM systems are potential candidates for contrast agents, especially at high magnetic fields.
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Affiliation(s)
- Aiswarya Chalikunnath Venu
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
| | - Rami Nasser Din
- LNCMI-EMFL, CNRS, INSA-T and UPS, Université Grenoble Alpes, Boîte Postale 166, CEDEX 9, 38042 Grenoble, France;
| | - Thomas Rudszuck
- Karlsruhe Institute of Technology (KIT), MVM-VM, Adenauerring 20b, 76131 Karlsruhe, Germany;
| | - Pierre Picchetti
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
| | - Papri Chakraborty
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
| | - Annie K. Powell
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131 Karlsruhe, Germany
- Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Steffen Krämer
- LNCMI-EMFL, CNRS, INSA-T and UPS, Université Grenoble Alpes, Boîte Postale 166, CEDEX 9, 38042 Grenoble, France;
| | - Gisela Guthausen
- Karlsruhe Institute of Technology (KIT), MVM-VM, Adenauerring 20b, 76131 Karlsruhe, Germany;
- Karlsruhe Institute of Technology (KIT), EBI-WCWT, Adenauerring 20b, 76131 Karlsruhe, Germany
| | - Masooma Ibrahim
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
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12
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Cicolari D, Santanni F, Grassi L, Brero F, Filibian M, Recca T, Arosio P, Perfetti M, Mariani M, Sessoli R, Lascialfari A. Longitudinal and transverse NMR relaxivities of Ln(III)-DOTA complexes: A comprehensive investigation. J Chem Phys 2021; 155:214201. [PMID: 34879662 DOI: 10.1063/5.0072185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Longitudinal and transverse 1H nuclear magnetic resonance relaxivities of Ln(III)-DOTA complexes (with Ln = Gd, Tb, Dy, Er; DOTA = 1,4,7,10-tetraazacyclododecane-N,N',N″,N‴-tetraacetic acid) and Mn(II) aqueous solutions were measured in a wide range of frequencies, 10 kHz to 700 MHz. The experimental data were interpreted by means of models derived from the Solomon-Bloembergen-Morgan theory. The data analysis was performed assuming the orbital angular momentum L = 0 for Gd-DOTA and the aqua ion [Mn(H2O)6]2+ and L ≠ 0 for Dy-, Tb-, and Er-DOTA. A refined estimation of the zero-field-splitting barrier Δ and of the modulation correlation time τv was obtained for [Mn(H2O)6]2+ by extending the fitting of nuclear magnetic relaxation dispersion profiles to the low-field regime. The Gd-DOTA fitting parameters resulted in good agreement with the literature, and the fit of transverse relaxivity data confirmed the negligibility of the scalar interaction in the nuclear relaxation mechanism. Larger transverse relaxivities of Dy-DOTA and Tb-DOTA (∼10 mM-1 s-1) with respect to Er-DOTA (∼1 mM-1 s-1) were observed at 16 T. Such higher values are suggested to be due to a shorter residence time τm that is possibly linked to the fluctuations of the hyperfine interaction and the different shape of the magnetic anisotropy. The possible employment of Dy-DOTA, Tb-DOTA, and Er-DOTA as negative magnetic resonance imaging contrast agents for high-field applications was envisaged by collecting spin-echo images at 7 T. Particularly in Dy- and Tb-derivatives, the transverse relaxivity at 16 T is of the order of the Gd-one at 1.5 T.
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Affiliation(s)
- Davide Cicolari
- Department of Physics, University of Pavia, Via Bassi 6, Pavia (PV) 27100, Italy
| | - Fabio Santanni
- Department of Chemistry, University of Florence, Sesto Fiorentino (FI) 50019, Italy
| | - Leonardo Grassi
- Department of Chemistry, University of Florence, Sesto Fiorentino (FI) 50019, Italy
| | - Francesca Brero
- Department of Physics, University of Pavia, Via Bassi 6, Pavia (PV) 27100, Italy
| | - Marta Filibian
- INFN, Istituto Nazionale di Fisica Nucleare-Pavia Unit, Via Bassi 6, Pavia (PV) 27100, Italy
| | - Teresa Recca
- Centro Grandi Strumenti, University of Pavia, Via Bassi 21, Pavia (PV) 27100, Italy
| | - Paolo Arosio
- Department of Physics, University of Milan, Via Celoria 16, Milan (MI) 20133, Italy
| | - Mauro Perfetti
- Department of Chemistry, University of Florence, Sesto Fiorentino (FI) 50019, Italy
| | - Manuel Mariani
- Department of Physics, University of Pavia, Via Bassi 6, Pavia (PV) 27100, Italy
| | - Roberta Sessoli
- Department of Chemistry, University of Florence, Sesto Fiorentino (FI) 50019, Italy
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13
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Zapolotsky EN, Qu Y, Babailov SP. Lanthanide complexes with polyaminopolycarboxylates as prospective NMR/MRI diagnostic probes: peculiarities of molecular structure, dynamics and paramagnetic properties. J INCL PHENOM MACRO 2021; 102:1-33. [PMID: 34785985 PMCID: PMC8582344 DOI: 10.1007/s10847-021-01112-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/05/2021] [Indexed: 11/29/2022]
Abstract
The paramagnetic lanthanide complexes with polyaminopolycarboxylate (PAPC) ligands attract considerable attention from the standpoint of potential applications thereof as relaxation agents used in medical magnetic resonance imaging (MRI) and in luminescent materials, as well as owing to promising use thereof as paramagnetic labels for studying the properties of biopolymers since they exhibit thermodynamic stability, good solubility in aqueous media and moderate toxicity. For the last decades, the NMR methods have been used to determine the physical and chemical properties of paramagnetic Ln compounds. The studies concerning paramagnetic NMR lanthanide-induced shifts (LISs) in dissolved Ln complexes, as well as the analysis of band shape as a function of temperature make it possible to obtain valuable information on the structure, intra- and intermolecular dynamics and paramagnetic properties thereof. This review is devoted solely to the following features: firstly, the processes of intramolecular dynamics of lanthanide complexes with polyamino-polycarboxylate ligands such as DOTA, EDTA and DTPA and their derivatives studied by NMR; secondly, the LISs of lanthanide complexes with EDTA, DOTA, DTPA and some of their derivatives depending on temperature and pH. Moreover, in this review, for the first time, the dependence of the activation energy of molecular dynamics in complexes with polydentate ligands on the atomic number of the lanthanide cation is analyzed and a monotonic change in energy is detected, which is due to the effect of lanthanide contraction. It should be noted that this phenomenon is quite general and may also appear in the future in many other series of lanthanide complexes with both other multidentate ligands and with bidentate and monodentate ligands. In the future, it is possible to predict the dependence of the properties of certain lanthanide complexes on the ionic radius of the lanthanide cation based on the approaches presented in the review. In this review, we have also presented the dynamic NMR as the main research method widely used to analyze the processes of molecular dynamics, and the structural studies based on the NMR relaxation spectroscopy and LIS analysis.
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Affiliation(s)
- Eugeny N. Zapolotsky
- A.V. Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Av. Lavrentyev 3, Novosibirsk, Russia 630090
| | - Yanyang Qu
- Institute of Chemical Materials, CAEP, P. O. Box 919-311, Mianyang, 621900 Sichun China
| | - Sergey P. Babailov
- A.V. Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Av. Lavrentyev 3, Novosibirsk, Russia 630090
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14
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Ott JC, Suturina EA, Kuprov I, Nehrkorn J, Schnegg A, Enders M, Gade LH. Observability of Paramagnetic NMR Signals at over 10 000 ppm Chemical Shifts. Angew Chem Int Ed Engl 2021; 60:22856-22864. [PMID: 34351041 PMCID: PMC8518043 DOI: 10.1002/anie.202107944] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Indexed: 12/27/2022]
Abstract
We report an experimental observation of 31 P NMR resonances shifted by over 10 000 ppm (meaning percent range, and a new record for solutions), and similar 1 H chemical shifts, in an intermediate-spin square planar ferrous complex [tBu (PNP)Fe-H], where PNP is a carbazole-based pincer ligand. Using a combination of electronic structure theory, nuclear magnetic resonance, magnetometry, and terahertz electron paramagnetic resonance, the influence of magnetic anisotropy and zero-field splitting on the paramagnetic shift and relaxation enhancement is investigated. Detailed spin dynamics simulations indicate that, even with relatively slow electron spin relaxation (T1 ≈10-11 s), it remains possible to observe NMR signals of directly metal-bonded atoms because pronounced rhombicity in the electron zero-field splitting reduces nuclear paramagnetic relaxation enhancement.
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Affiliation(s)
- Jonas C. Ott
- Anorganisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27669120HeidelbergGermany
| | | | - Ilya Kuprov
- School of ChemistryUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Joscha Nehrkorn
- EPR Research GroupMPI for Chemical Energy ConversionStiftstrasse 34–3645470Mülheim RuhrGermany
| | - Alexander Schnegg
- EPR Research GroupMPI for Chemical Energy ConversionStiftstrasse 34–3645470Mülheim RuhrGermany
| | - Markus Enders
- Anorganisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27669120HeidelbergGermany
| | - Lutz H. Gade
- Anorganisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27669120HeidelbergGermany
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15
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Ott JC, Suturina EA, Kuprov I, Nehrkorn J, Schnegg A, Enders M, Gade LH. Observability of Paramagnetic NMR Signals at over 10 000 ppm Chemical Shifts. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202107944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jonas C. Ott
- Anorganisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 276 69120 Heidelberg Germany
| | | | - Ilya Kuprov
- School of Chemistry University of Southampton Southampton SO17 1BJ UK
| | - Joscha Nehrkorn
- EPR Research Group MPI for Chemical Energy Conversion Stiftstrasse 34–36 45470 Mülheim Ruhr Germany
| | - Alexander Schnegg
- EPR Research Group MPI for Chemical Energy Conversion Stiftstrasse 34–36 45470 Mülheim Ruhr Germany
| | - Markus Enders
- Anorganisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 276 69120 Heidelberg Germany
| | - Lutz H. Gade
- Anorganisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 276 69120 Heidelberg Germany
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16
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Abstract
Nuclear Magnetic Resonance is particularly sensitive to the electronic structure of matter and is thus a powerful tool to characterize in-depth the magnetic properties of a system. NMR is indeed increasingly recognized as an ideal tool to add precious structural information for the development of Single Ion Magnets, small complexes that are recently gaining much popularity due to their quantum computing and spintronics applications. In this review, we recall the theoretical principles of paramagnetic NMR, with particular attention to lanthanoids, and we give an overview of the recent advances in this field.
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17
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Tm-DOTA as responsive relaxation and shift probe for NMR local temperature monitoring at high magnetic fields. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.120153] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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18
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Sequence-specific assignments in NMR spectra of paramagnetic systems: A non-systematic approach. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.119984] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Dy-DTPA as supersensitive shifting and relaxational probe for NMR/MRI control of local temperature. Polyhedron 2021. [DOI: 10.1016/j.poly.2020.114908] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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20
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Trindade IB, Invernici M, Cantini F, Louro RO, Piccioli M. PRE-driven protein NMR structures: an alternative approach in highly paramagnetic systems. FEBS J 2020; 288:3010-3023. [PMID: 33124176 DOI: 10.1111/febs.15615] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 09/10/2020] [Accepted: 10/28/2020] [Indexed: 01/29/2023]
Abstract
Metalloproteins play key roles across biology, and knowledge of their structure is essential to understand their physiological role. For those metalloproteins containing paramagnetic states, the enhanced relaxation caused by the unpaired electrons often makes signal detection unfeasible near the metal center, precluding adequate structural characterization right where it is more biochemically relevant. Here, we report a protein structure determination by NMR where two different sets of restraints, one containing Nuclear Overhauser Enhancements (NOEs) and another containing Paramagnetic Relaxation Enhancements (PREs), are used separately and eventually together. The protein PioC from Rhodopseudomonas palustris TIE-1 is a High Potential Iron-Sulfur Protein (HiPIP) where the [4Fe-4S] cluster is paramagnetic in both oxidation states at room temperature providing the source of PREs used as alternative distance restraints. Comparison of the family of structures obtained using NOEs only, PREs only, and the combination of both reveals that the pairwise root-mean-square deviation (RMSD) between them is similar and comparable with the precision within each family. This demonstrates that, under favorable conditions in terms of protein size and paramagnetic effects, PREs can efficiently complement and eventually replace NOEs for the structural characterization of small paramagnetic metalloproteins and de novo-designed metalloproteins by NMR. DATABASES: The 20 conformers with the lowest target function constituting the final family obtained using the full set of NMR restraints were deposited to the Protein Data Bank (PDB ID: 6XYV). The 20 conformers with the lowest target function obtained using NOEs only (PDB ID: 7A58) and PREs only (PDB ID: 7A4L) were also deposited to the Protein Data Bank. The chemical shift assignments were deposited to the BMRB (code 34487).
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Affiliation(s)
- Inês B Trindade
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
| | - Michele Invernici
- Magnetic Resonance Center and Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
| | - Francesca Cantini
- Magnetic Resonance Center and Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
| | - Ricardo O Louro
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mario Piccioli
- Magnetic Resonance Center and Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
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21
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Paramagnetic NMR Spectroscopy Is a Tool to Address Reactivity, Structure, and Protein–Protein Interactions of Metalloproteins: The Case of Iron–Sulfur Proteins. MAGNETOCHEMISTRY 2020. [DOI: 10.3390/magnetochemistry6040046] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The study of cellular machineries responsible for the iron–sulfur (Fe–S) cluster biogenesis has led to the identification of a large number of proteins, whose importance for life is documented by an increasing number of diseases linked to them. The labile nature of Fe–S clusters and the transient protein–protein interactions, occurring during the various steps of the maturation process, make their structural characterization in solution particularly difficult. Paramagnetic nuclear magnetic resonance (NMR) has been used for decades to characterize chemical composition, magnetic coupling, and the electronic structure of Fe–S clusters in proteins; it represents, therefore, a powerful tool to study the protein–protein interaction networks of proteins involving into iron–sulfur cluster biogenesis. The optimization of the various NMR experiments with respect to the hyperfine interaction will be summarized here in the form of a protocol; recently developed experiments for measuring longitudinal and transverse nuclear relaxation rates in highly paramagnetic systems will be also reviewed. Finally, we will address the use of extrinsic paramagnetic centers covalently bound to diamagnetic proteins, which contributed over the last twenty years to promote the applications of paramagnetic NMR well beyond the structural biology of metalloproteins.
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22
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Di Mauro GM, Hardin NZ, Ramamoorthy A. Lipid-nanodiscs formed by paramagnetic metal chelated polymer for fast NMR data acquisition. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2020; 1862:183332. [PMID: 32360741 PMCID: PMC7340147 DOI: 10.1016/j.bbamem.2020.183332] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/21/2020] [Accepted: 04/27/2020] [Indexed: 02/07/2023]
Abstract
Lipid-nanodiscs have been shown to be an exciting innovation as a membrane-mimicking system for studies on membrane proteins by a variety of biophysical techniques, including NMR spectroscopy. Although NMR spectroscopy is unique in enabling the atomic-resolution investigation of dynamic structures of membrane-associated molecules, it, unfortunately, suffers from intrinsically low sensitivity. The long data acquisition often used to enhance the sensitivity is not desirable for sensitive membrane proteins. Instead, paramagnetic relaxation enhancement (PRE) has been used to reduce NMR data acquisition time or to reduce the amount of sample required to acquire an NMR spectra. However, the PRE approach involves the introduction of external paramagnetic probes in the system, which can induce undesired changes in the sample and on the observed NMR spectra. For example, the addition of paramagnetic ions, as frequently used, can denature the protein via direct interaction and also through sample heating. In this study, we show how the introduction of paramagnetic tags on the outer belt of polymer-nanodiscs can be used to speed-up data acquisition by significantly reducing the spin-lattice relaxation (T1) times with minimum-to-no alteration of the spectral quality. Our results also demonstrate the feasibility of using different types of paramagnetic ions (Eu3+, Gd3+, Dy3+, Er3+, Yb3+) for NMR studies on lipid-nanodiscs. Experimental results characterizing the formation of lipid-nanodiscs by the metal-chelated polymer, and their increased tolerance toward metal ions are also reported.
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Affiliation(s)
- Giacomo M Di Mauro
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Nathaniel Z Hardin
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Biophysics and Chemistry Department, The University of Michigan, Ann Arbor, MI 48109-1055, USA; Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA; Biomedical Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA.
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23
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Parker D, Suturina EA, Kuprov I, Chilton NF. How the Ligand Field in Lanthanide Coordination Complexes Determines Magnetic Susceptibility Anisotropy, Paramagnetic NMR Shift, and Relaxation Behavior. Acc Chem Res 2020; 53:1520-1534. [PMID: 32667187 PMCID: PMC7467575 DOI: 10.1021/acs.accounts.0c00275] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Indexed: 01/27/2023]
Abstract
Complexes of lanthanide(III) ions are being actively studied because of their unique ground and excited state properties and the associated optical and magnetic behavior. In particular, they are used as emissive probes in optical spectroscopy and microscopy and as contrast agents in magnetic resonance imaging (MRI). However, the design of new complexes with specific optical and magnetic properties requires a thorough understanding of the correlation between molecular structure and electric and magnetic susceptibilities, as well as their anisotropies. The traditional Judd-Ofelt-Mason theory has failed to offer useful guidelines for systematic design of emissive lanthanide optical probes. Similarly, Bleaney's theory of magnetic anisotropy and its modifications fail to provide accurate detail that permits new paramagnetic shift reagents to be designed rather than discovered.A key determinant of optical and magnetic behavior in f-element compounds is the ligand field, often considered as an electrostatic field at the lanthanide created by the ligands. The resulting energy level splitting is a sensitive function of several factors: the nature and polarizability of the whole ligand and its donor atoms; the geometric details of the coordination polyhedron; the presence and extent of solvent interactions; specific hydrogen bonding effects on donor atoms and the degree of supramolecular order in the system. The relative importance of these factors can vary widely for different lanthanide ions and ligands. For nuclear magnetic properties, it is both the ligand field splitting and the magnetic susceptibility tensor, notably its anisotropy, that determine paramagnetic shifts and nuclear relaxation enhancement.We review the factors that control the ligand field in lanthanide complexes and link these to aspects of their utility in magnetic resonance and optical emission spectroscopy and imaging. We examine recent progress in this area particularly in the theory of paramagnetic chemical shift and relaxation enhancement, where some long-neglected effects of zero-field splitting, magnetic susceptibility anisotropy, and spatial distribution of lanthanide tags have been accommodated in an elegant way.
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Affiliation(s)
- David Parker
- Department
of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K.
| | | | - Ilya Kuprov
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K.
| | - Nicholas F. Chilton
- Department
of Chemistry, School of Natural Sciences, The University of Manchester, Manchester M13 9PL, U.K.
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24
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Webber BC, Payne KM, Rust LN, Cassino C, Carniato F, McCormick T, Botta M, Woods M. Analysis of the Relaxometric Properties of Extremely Rapidly Exchanging Gd 3+ Chelates: Lessons from a Comparison of Four Isomeric Chelates. Inorg Chem 2020; 59:9037-9046. [PMID: 32536158 DOI: 10.1021/acs.inorgchem.0c00905] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Relaxometric analyses and in particular the use of fast-field cycling techniques have become routine in the study of paramagnetic metal complexes. The field dependence of the solvent proton relaxation properties (nuclear magnetic relaxation dispersion, NMRD) can provide unparalleled insights into the chemistry of these complexes. However, analyzing NMRD data is a multiparametric problem, and some sets of variables are mutually compensatory. Specifically, when fitting NMRD profiles, the metal-proton distance and the rotational correlation time constant have a push-pull relationship in which a change to one causes a predictable compensation in the other. A relaxometric analysis of four isomeric chelates highlights the pitfalls that await when fitting the NMRD profiles of chelates for which dissociative water exchange is extremely rapid. In the absence of independently verified values for one of these parameters, NMRD profiles can be fitted to multiple parameter sets. This means that NMRD fitting can inadvertently be used to buttress a preconceived notion of how the complex should behave when a different parameter set may more accurately describe the actual behavior. These findings explain why the effect of very rapid dissociative exchange on the hydration state of Gd3+ has remained obscured until only recently.
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Affiliation(s)
- Benjamin C Webber
- Department of Chemistry, Portland State University, 1719 SW 10th Avenue, Portland, Oregon 97201, United States
| | - Katherine M Payne
- Department of Chemistry, Portland State University, 1719 SW 10th Avenue, Portland, Oregon 97201, United States
| | - Lauren N Rust
- Department of Chemistry, Portland State University, 1719 SW 10th Avenue, Portland, Oregon 97201, United States
| | - Claudio Cassino
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro″, Viale T. Michel 11, I-15121 Alessandria, Italy
| | - Fabio Carniato
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro″, Viale T. Michel 11, I-15121 Alessandria, Italy
| | - Theresa McCormick
- Department of Chemistry, Portland State University, 1719 SW 10th Avenue, Portland, Oregon 97201, United States
| | - Mauro Botta
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro″, Viale T. Michel 11, I-15121 Alessandria, Italy
| | - Mark Woods
- Department of Chemistry, Portland State University, 1719 SW 10th Avenue, Portland, Oregon 97201, United States.,Advanced Imaging Research Center, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
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25
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Yu M, Xie D, Kadakia RT, Wang W, Que EL. Harnessing chemical exchange: 19F magnetic resonance OFF/ON zinc sensing with a Tm(iii) complex. Chem Commun (Camb) 2020; 56:6257-6260. [PMID: 32373870 DOI: 10.1039/d0cc01876g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A fluorinated, thulium(iii) complex (Tm-PFZ-1) serves as an off-on 19F magnetic resonance probe for Zn(ii). Rapid exchange among different conformations combined with paramagnetic relaxation and chemical shift effects of Tm(iii) effectively eliminate the 19F NMR/MRI signal in Tm-PFZ-1. Chelation of Zn(ii) induces increased structural rigidity and reduces exchange rate, affording a robust 19F NMR/MRI signal. Tm-PFZ-1 represents a first-in-class paramagnetic 19F MR agent that exploits a novel sensing mechanism for Zn(ii) and is the first 19F MR-based scaffold to provide an "off-on" response to Zn(ii) in aqueous solution.
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Affiliation(s)
- Meng Yu
- Department of Chemistry, The University of Texas at Austin, 105 E. 24th St Stop A5300, Austin, Texas 78712, USA.
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26
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Peters JA, Djanashvili K, Geraldes CF, Platas-Iglesias C. The chemical consequences of the gradual decrease of the ionic radius along the Ln-series. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2019.213146] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Orton H, Huber T, Otting G. Paramagpy: software for fitting magnetic susceptibility tensors using paramagnetic effects measured in NMR spectra. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2020; 1:1-12. [PMID: 37904891 PMCID: PMC10500712 DOI: 10.5194/mr-1-1-2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/20/2020] [Indexed: 11/01/2023]
Abstract
Paramagnetic metal ions with fast-relaxing electrons generate pseudocontact shifts (PCSs), residual dipolar couplings (RDCs), paramagnetic relaxation enhancements (PREs) and cross-correlated relaxation (CCR) in the nuclear magnetic resonance (NMR) spectra of the molecules they bind to. These effects offer long-range structural information in molecules equipped with binding sites for such metal ions. Here we present the new open-source software Paramagpy, which has been written in Python 3 with a graphic user interface. Paramagpy combines the functionalities of different currently available programs to support the fitting of magnetic susceptibility tensors using PCS, RDC, PRE and CCR data and molecular coordinates in Protein Data Bank (PDB) format, including a convenient graphical user interface. Paramagpy uses efficient fitting algorithms to avoid local minima and supports corrections to back-calculated PCS and PRE data arising from cross-correlation effects with chemical shift tensors. The source code is available from 10.5281/zenodo.3594568 .
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Affiliation(s)
- Henry William Orton
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Thomas Huber
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Gottfried Otting
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
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Parigi G, Ravera E, Luchinat C. Magnetic susceptibility and paramagnetism-based NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2019; 114-115:211-236. [PMID: 31779881 DOI: 10.1016/j.pnmrs.2019.06.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/17/2019] [Accepted: 06/17/2019] [Indexed: 05/18/2023]
Abstract
The magnetic interactions between the nuclear magnetic moment and the magnetic moment of unpaired electron(s) depend on the structure and dynamics of the molecules where the paramagnetic center is located and of their partners. The long-range nature of the magnetic interactions is thus a reporter of invaluable information for structural biology studies, when other techniques often do not provide enough data for the atomic-level characterization of the system. This precious information explains the flourishing of paramagnetism-assisted NMR studies in recent years. Many paramagnetic effects are related to the magnetic susceptibility of the paramagnetic metal. Although these effects have been known for more than half a century, different theoretical models and new approaches have been proposed in the last decade. In this review, we have summarized the consequences for NMR spectroscopy of magnetic interactions between nuclear and electron magnetic moments, and thus of the presence of a magnetic susceptibility due to metals, and we do so using a unified notation.
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Affiliation(s)
- Giacomo Parigi
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Enrico Ravera
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy; Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy.
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Harris M, Biju S, Parac‐Vogt TN. High‐Field MRI Contrast Agents and their Synergy with Optical Imaging: the Evolution from Single Molecule Probes towards Nano‐architectures. Chemistry 2019; 25:13838-13847. [DOI: 10.1002/chem.201901141] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/03/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Michael Harris
- Department of ChemistryKU Leuven Celestijnenlaan 200F Heverlee 3001 Belgium
| | - Silvanose Biju
- Department of ChemistryGovt. Arts College Thiruvananthapuram Kerala 695014 India
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Harnden AC, Suturina EA, Batsanov AS, Senanayake PK, Fox MA, Mason K, Vonci M, McInnes EJL, Chilton NF, Parker D. Unravelling the Complexities of Pseudocontact Shift Analysis in Lanthanide Coordination Complexes of Differing Symmetry. Angew Chem Int Ed Engl 2019; 58:10290-10294. [DOI: 10.1002/anie.201906031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Alice C. Harnden
- Department of ChemistryDurham University South Road Durham DH1 3LE UK
| | | | | | | | - Mark A. Fox
- Department of ChemistryDurham University South Road Durham DH1 3LE UK
| | - Kevin Mason
- Department of ChemistryDurham University South Road Durham DH1 3LE UK
| | - Michele Vonci
- School of Chemistry and Photon Science InstituteThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Eric J. L. McInnes
- School of Chemistry and Photon Science InstituteThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Nicholas F. Chilton
- School of Chemistry and Photon Science InstituteThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - David Parker
- Department of ChemistryDurham University South Road Durham DH1 3LE UK
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Babailov SP, Zapolotsky EN, Basova TV. Holmium-DOTA as a responsive relaxation paramagnetic probe for NMR/MRI control of local temperature at high magnetic fields. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2019.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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32
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Harnden AC, Suturina EA, Batsanov AS, Senanayake PK, Fox MA, Mason K, Vonci M, McInnes EJL, Chilton NF, Parker D. Unravelling the Complexities of Pseudocontact Shift Analysis in Lanthanide Coordination Complexes of Differing Symmetry. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201906031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Alice C. Harnden
- Department of ChemistryDurham University South Road Durham DH1 3LE UK
| | | | | | | | - Mark A. Fox
- Department of ChemistryDurham University South Road Durham DH1 3LE UK
| | - Kevin Mason
- Department of ChemistryDurham University South Road Durham DH1 3LE UK
| | - Michele Vonci
- School of Chemistry and Photon Science InstituteThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Eric J. L. McInnes
- School of Chemistry and Photon Science InstituteThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Nicholas F. Chilton
- School of Chemistry and Photon Science InstituteThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - David Parker
- Department of ChemistryDurham University South Road Durham DH1 3LE UK
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Rust L, Payne KM, Carniato F, Botta M, Woods M. Differences in the Relaxometric Properties of Regioisomeric Benzyl-DOTA Bifunctional Chelators: Implications for Molecular Imaging. Bioconjug Chem 2019; 30:1530-1538. [PMID: 31050414 DOI: 10.1021/acs.bioconjchem.9b00223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The bifunctional chelator S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane- N, N', N″, N‴-1,4,7,10-tetraacetate (IB-DOTA) is on paper the most attractive of the commercially available bifunctional chelators for magnetic resonance imaging (MRI) applications. The preserved DOTA scaffold is known to produce extremely kinetically and thermodynamically robust chelates with the Gd3+ ion. Also, ligation through four acetate pendant arms should ensure that the rapid water exchange kinetics so, crucial to the function of an MRI contrast agent are retained. However, upon ligation of the Gd3+ ion, IB-DOTA differentiates into two distinct isomers defined by the positions of the benzylic substituent (corner or side). A relaxometric analysis of these two isomers revealed marked differences in the property and behavior of the two chelates. Most notably the side isomer is found to be substantially more likely to aggregate in aqueous solution than its corner counterpart. This aggregation results in higher relaxivity for the side isomer versus the corner isomer, an observation that potentially obscures the impact of differences in water exchange kinetics between the two isomers. The side isomer is composed of a significant fraction of a twisted square antiprismatic coordination geometry that exchanges water more rapidly than optimal (τM = 7 ns) for maximizing relaxivity. The impact of this excessively fast exchange is not observed in the relaxivity of the side isomer only because in isolation this chelate tumbles much more slowly than the corner isomer. However, this situation is not expected to persist when the chelate is employed in a typical bioconjugate. These results imply that the corner isomer of IB-DOTA may represent a better choice of bifunctional chelator for bioconjugation applications in which a large macromolecule is to be tagged for MRI applications.
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Affiliation(s)
- Lauren Rust
- Department of Chemistry , Portland State University , 1719 SW 10th Avenue , Portland , Oregon 97201 , United States
| | - Katherine M Payne
- Department of Chemistry , Portland State University , 1719 SW 10th Avenue , Portland , Oregon 97201 , United States
| | - Fabio Carniato
- Dipartimento di Scienze e Innovazione Tecnologica , Università del Piemonte Orientale "Amedeo Avogadro" , Viale T. Michel 11 , I-15121 Alessandria , Italy
| | - Mauro Botta
- Dipartimento di Scienze e Innovazione Tecnologica , Università del Piemonte Orientale "Amedeo Avogadro" , Viale T. Michel 11 , I-15121 Alessandria , Italy
| | - Mark Woods
- Department of Chemistry , Portland State University , 1719 SW 10th Avenue , Portland , Oregon 97201 , United States.,Advanced Imaging Research Center , Oregon Health and Science University , 3181 SW Sam Jackson Park Road , Portland , Oregon 97239 , United States
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Ott JC, Wadepohl H, Enders M, Gade LH. Taking Solution Proton NMR to Its Extreme: Prediction and Detection of a Hydride Resonance in an Intermediate-Spin Iron Complex. J Am Chem Soc 2018; 140:17413-17417. [PMID: 30486649 DOI: 10.1021/jacs.8b11330] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Guided by DFT based modeling the chemical shift range of a hydride resonance in the proton nuclear magnetic resonance (NMR) spectrum of the intermediate-spin, square planar iron complex tBu(PNP)Fe-H was predicted and detected as a broad resonance at -3560 ppm (295 K) with a temperature dependent shift of approximately 2000 ppm between 223 and 383 K. The first detection of a metal-bonded hydrogen atom by solution NMR in a complex with a paramagnetic ground state illustrates the interplay of theory and experiment for the characterization of key components in paramagnetic base metal catalysis.
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Affiliation(s)
- Jonas C Ott
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
| | - Markus Enders
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
| | - Lutz H Gade
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
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Ravera E, Takis PG, Fragai M, Parigi G, Luchinat C. NMR Spectroscopy and Metal Ions in Life Sciences. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800875] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Enrico Ravera
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP); Via L. Sacconi 6 50019 Sesto Fiorentino Italy
- Department of Chemistry “Ugo Schiff”; University of Florence; Via della Lastruccia 3 50019 Sesto Fiorentino Italy
| | - Panteleimon G. Takis
- Giotto Biotech S.R.L.; Via Madonna del Piano 6 50019 Sesto Fiorentino (FI) Italy
| | - Marco Fragai
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP); Via L. Sacconi 6 50019 Sesto Fiorentino Italy
- Department of Chemistry “Ugo Schiff”; University of Florence; Via della Lastruccia 3 50019 Sesto Fiorentino Italy
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP); Via L. Sacconi 6 50019 Sesto Fiorentino Italy
- Department of Chemistry “Ugo Schiff”; University of Florence; Via della Lastruccia 3 50019 Sesto Fiorentino Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) and Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP); Via L. Sacconi 6 50019 Sesto Fiorentino Italy
- Department of Chemistry “Ugo Schiff”; University of Florence; Via della Lastruccia 3 50019 Sesto Fiorentino Italy
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