1
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Liu W, Tao O, Chen L, Ling Y, Zeng M, Jin H, Jiang D. Synthesis and characterization of a Cu(ii) coordination-containing TAM radical as a nitroxyl probe. RSC Adv 2022; 12:15980-15985. [PMID: 35733682 PMCID: PMC9138401 DOI: 10.1039/d1ra07511j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 04/14/2022] [Indexed: 11/21/2022] Open
Abstract
Nitroxyl (HNO) has been identified as an important signaling molecule in biological systems, and it plays critical roles in many physiological processes. However, its detection remains challenging because of the limited sensitivity and/or specificity of existing detection methods. Low-frequency electron paramagnetic resonance (EPR) spectroscopy and imaging, coupled with the use of exogenous paramagnetic probes, have been indispensable techniques for the in vivo measurement of various physiological parameters owing to their specificity, noninvasiveness and good depth of magnetic field penetration in animal tissues. However, the in vivo detection of HNO levels by EPR spectroscopy and imaging is limited due to the need for improved probes. We report the first "turn on-response" EPR probe for HNO utilizing a Cu(ii) coordination-containing TAM radical (denoted as CuII[TD1]). Upon reaction with HNO, CuII[TD1] shows a 16.1-fold turn-on in EPR signal with a low detection limit of 1.95 μM. Moreover, low-temperature EPR spectroscopic and ESI-MS studies showed that the sensing mechanism relies on the reduction of Cu(ii) by HNO. Lastly, CuII[TD1] is selective for HNO over other reactive nitrogen and oxygen species except for some reductants (Cys and Asc). This new Cu(ii) coordination-containing TAM radical shows great potential for in vivo EPR HNO applications in the absence of reducing agents and provides insights into developing improved and targeted EPR HNO probes for biomedical applications.
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Affiliation(s)
- Wenbo Liu
- School of Pharmacy and Life Sciences, Jiujiang University Jiujiang 332000 China
| | - Ouyang Tao
- School of Pharmacy and Life Sciences, Jiujiang University Jiujiang 332000 China
| | - Li Chen
- School of Public Health, TianJin Medical University China
| | - Yun Ling
- School of Pharmacy and Life Sciences, Jiujiang University Jiujiang 332000 China
| | - Ming Zeng
- School of Pharmacy and Life Sciences, Jiujiang University Jiujiang 332000 China
| | - Hongguang Jin
- School of Pharmacy and Life Sciences, Jiujiang University Jiujiang 332000 China
| | - Dengzhao Jiang
- School of Pharmacy and Life Sciences, Jiujiang University Jiujiang 332000 China
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2
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Moore W, Yao R, Liu Y, Eaton SS, Eaton GR. Spin-spin interaction and relaxation in two trityl-nitroxide diradicals. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 332:107078. [PMID: 34649176 PMCID: PMC8592039 DOI: 10.1016/j.jmr.2021.107078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/24/2021] [Accepted: 08/30/2021] [Indexed: 05/11/2023]
Abstract
Trityl-nitroxides show substantial promise as polarizing agents in solid state dynamic nuclear polarization. To optimize performance it is important to understand the impact of spin-spin interactions on relaxation times of the diradicals. CW spectra and electron spin relaxation were measured for two trityl-nitroxides that differ in the substituents on the amide linker and have different strengths of the exchange interaction J. Analysis of the EPR spectra in terms of overlapping AB spin-spin splitting patterns explains the impact of J on various regions of the spectra. Even modest values of J are large relative to the separation between trityl and nitroxide resonances for some nitrogen nuclear spin state. Two conformations for each diradical were observed in CW spectra in fluid solution at X-band and Q-band. For one diradical J = 15 G (83%) and 5 G (17%) at 293 K, and J = 27 G (67%) and 3 G (33%) with interspin distances of 16 Å and 12 Å, respectively, at 80 K. For the second diradical the exchange interaction is stronger: the two conformations in fluid solution at 293 K had J = 113 G (67%) and 59 G (33%) and at 80 K the value of J was 43 G and there were two conformations with interspin distances of 13 and 11.5 Å. The observation of two conformations for each diradical, with different values of J, demonstrates the dependence of their exchange interactions on through-bond orbital interactions. X-band values of spin relaxation rates 1/T1 and 1/Tm at 80 to 120 K for the trityl-nitroxides are similar to values for nitroxide mono-radicals, and faster than for trityl radicals. These observations show that even for a relatively small value of J, the nitroxide is very effective in enhancing the relaxation of the more slowly relaxing trityl.
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Affiliation(s)
- Whylder Moore
- Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80210, United States
| | - Ru Yao
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, PR China
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, PR China.
| | - Sandra S Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80210, United States
| | - Gareth R Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80210, United States.
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3
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Chen L, Wu L, Tan X, Rockenbauer A, Song Y, Liu Y. Synthesis and Redox Properties of Water-Soluble Asymmetric Trityl Radicals. J Org Chem 2021; 86:8351-8364. [PMID: 34043350 DOI: 10.1021/acs.joc.1c00766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tetrathiatriarylmethyl (trityl) radicals have been recently shown to react with biological oxidoreductants including glutathione (GSH), ascorbic acid (Asc), and superoxide anion radical (O2•-). However, how the substituents affect the reactivity of trityl radicals is still unknown. In this work, five asymmetric trityl radicals were synthesized and their reactivities with GSH, Asc, and O2•- investigated. Under aerobic conditions, GSH induces fast decays for the thioether- (TSA) and N-methyleneglycine-substituted (TGA) derivatives and slow decay for the 4-carboxyphenyl-containing one (TPA). Under anaerobic conditions, the direct reduction of these radicals by GSH also occurs with rate constants (kGSH) from 1.8 × 10-4 M-1 s-1 for TPA to 1.0 × 10-2 M-1 s-1 for TGA. Moreover, these radicals can also react with O2•- with rate constants (kSO) from 1.2 × 103 M-1 s-1 for ET-01 to 1.6 × 104 M-1 s-1 for TGA. Surprisingly, these radicals are completely inert to Asc in both aerobic and anaerobic conditions. Additionally, the substituents exert an important effect on redox potentials of these trityl radicals. This work demonstrates that the redox properties of the trityl radicals strongly depend on their substituents, and TPA with high stability toward GSH shows great potential for intracellular applications.
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Affiliation(s)
- Li Chen
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, Department of Medicinal Chemistry, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Lanlan Wu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, Department of Medicinal Chemistry, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Xiaoli Tan
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, Department of Medicinal Chemistry, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Antal Rockenbauer
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Hungary.,Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111 Budapest, Hungary
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, Department of Medicinal Chemistry, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, Department of Medicinal Chemistry, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
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4
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Zhai W, Lucini Paioni A, Cai X, Narasimhan S, Medeiros-Silva J, Zhang W, Rockenbauer A, Weingarth M, Song Y, Baldus M, Liu Y. Postmodification via Thiol-Click Chemistry Yields Hydrophilic Trityl-Nitroxide Biradicals for Biomolecular High-Field Dynamic Nuclear Polarization. J Phys Chem B 2020; 124:9047-9060. [PMID: 32961049 DOI: 10.1021/acs.jpcb.0c08321] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Dynamic nuclear polarization (DNP) is a powerful method to enhance nuclear magnetic resonance (NMR) signal intensities, enabling unprecedented applications in life and material science. An ultimate goal is to expand the use of DNP-enhanced solid-state NMR to ultrahigh magnetic fields where optimal spectral resolution and sensitivity are integrated. Trityl-nitroxide (TN) biradicals have attracted significant interest in high-field DNP, but their application to complex (bio)molecules has so far been limited. Here we report a novel postmodification strategy for synthesis of hydrophilic TN biradicals in order to improve their use in biomolecular applications. Initially, three TN biradicals (referred to as NATriPols 1-3) with amino-acid linkers were synthesized. EPR studies showed that the α-position of the amino-acid linkers is an ideal modification site for these biradicals since their electron-electron magnetic interactions are marginally affected by the substituents at this position. On the basis of this finding, we synthesized NATriPol-4 with pyridine disulfide appended at the α-position. Postmodification of NATriPol-4 via thiol-click chemistry resulted in various TN biradicals including hydrophilic NATriPol-5 in a quantitative manner. Interestingly, DNP enhancements at 18.8 T of NATriPols for 13C,15N-proline in a glycerol/water matrix are inversely correlated with their hydrophobicity. Importantly, applications of hydrophilic NATriPol-5 and NATriPol-3 to biomolecules including a globular soluble protein and a membrane targeting peptide reveal significantly improved performance compared to TEMTriPol-1 and AMUPol. Our work provides an efficient approach for one-step synthesis of new polarizing agents with tunable physicochemical properties, thus expediting optimization of new biradicals for biomolecular applications at ultrahigh magnetic fields.
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Affiliation(s)
- Weixiang Zhai
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Alessandra Lucini Paioni
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Xinyi Cai
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Siddarth Narasimhan
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - João Medeiros-Silva
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Wenxiao Zhang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Antal Rockenbauer
- Institute of Materials and Environmental Chemistry, Hungarian Academy of Sciences, and Department of Physics, Budapest University of Technology and Economics, Budafokiut 8, 1111 Budapest, Hungary
| | - Markus Weingarth
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
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5
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Demay-Drouhard P, Ching HYV, Decroos C, Guillot R, Li Y, Tabares LC, Policar C, Bertrand HC, Un S. Understanding the g-tensors of perchlorotriphenylmethyl and Finland-type trityl radicals. Phys Chem Chem Phys 2020; 22:20792-20800. [PMID: 32909565 DOI: 10.1039/d0cp03626a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The 285 GHz EPR spectra of perchlorotriphenylmethyl and tetrathiatriarylmethyl radicals in frozen solution have been accurately measured. The relationship between their molecular structures and their g-tensors has been investigated with the aid of DFT calculations, revealing that the degree of spin density delocalization away from the central methylene carbon is an important determining factor of the g-anisotropy. In particular, the small amount of spin densities on the Cl or S heteroatoms at the 2 and 6 positions with respect to the central carbon have the strongest influence. Furthermore, the amount of spin densities on these heteroatoms and thus the anisotropy can be modulated by the protonation (esterification) state of the carboxylate groups at the 4 position. These results provide unique insights into the g-anisotropy of persistent trityl radicals and how it can be tuned.
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Affiliation(s)
- Paul Demay-Drouhard
- Laboratoire des Biomolécules, LBM, Département de Chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
| | - H Y Vincent Ching
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
| | - Christophe Decroos
- Aix Marseille Université, CNRS, Centrale Marseille, iSm2, Marseille, France
| | - Régis Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud, CNRS UMR 8182, Université Paris-Saclay, 91405 Orsay, France
| | - Yun Li
- Laboratoire de Chimie des Processus Biologiques, CNRS UMR 8229, Collège de France, PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Leandro C Tabares
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
| | - Clotilde Policar
- Laboratoire des Biomolécules, LBM, Département de Chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
| | - Helene C Bertrand
- Laboratoire des Biomolécules, LBM, Département de Chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
| | - Sun Un
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
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6
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Wang X, Peng C, He K, Ji K, Tan X, Han G, Liu Y, Liu Y, Song Y. Intracellular delivery of liposome-encapsulated Finland trityl radicals for EPR oximetry. Analyst 2020; 145:4964-4971. [PMID: 32510063 DOI: 10.1039/d0an00108b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Tetrathiatriarylmethyl (TAM, trityl) radicals have found wide applications in electron paramagnetic resonance (EPR) oximetry. However, the biomedical applications of TAM radicals were exclusively limited to an extracellular region owing to their negatively charged nature. The intracellular delivery of TAM radicals still remains a challenge. In the present work, we report a liposome-based method to encapsulate the water-soluble Finland trityl radical CT-03 for its intracellular delivery. Using the thin lipid film hydration method, CT-03-loaded liposomes were prepared from DSPC/cholesterol/DOTAP with a mean size of 167.5 ± 2.4 nm and a zeta potential of 27.8 ± 0.8 mV. EPR results showed that CT-03 was entrapped into the liposomes and still exhibited good oxygen (O2) sensitivity. Moreover, CT-03 was successfully delivered into HepG2 cells and HUVECs using the CT-03-loaded liposomes. Importantly, the combination of the liposome-encapsulated radical CT-03 and the other TAM radical CT02-H enabled simultaneous measurements of the intracellular and extracellular O2 concentrations and O2 consumption rates in HepG2 cells. Our present study provides a new approach for intracellular delivery of TAM radicals and could significantly expand their biomedical applications.
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Affiliation(s)
- Xing Wang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China.
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7
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Tan X, Ji K, Wang X, Yao R, Han G, Villamena FA, Zweier JL, Song Y, Rockenbauer A, Liu Y. Discriminative Detection of Biothiols by Electron Paramagnetic Resonance Spectroscopy using a Methanethiosulfonate Trityl Probe. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201912832] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Xiaoli Tan
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Kaiyun Ji
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Xing Wang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Ru Yao
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Guifang Han
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Frederick A. Villamena
- Department of Biological Chemistry and PharmacologyCollege of MedicineThe Ohio State University Columbus OH 43210 USA
| | - Jay L. Zweier
- Center for Biomedical EPR Spectroscopy and ImagingThe Davis Heart and Lung Research Institutethe Division of Cardiovascular MedicineDepartment of Internal MedicineThe Ohio State University Columbus OH 43210 USA
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Antal Rockenbauer
- Institute of Materials and Environmental ChemistryResearch Centre for Natural SciencesHungarian Academy of Sciences 1117 Budapest Hungary
- Department of PhysicsBudapest University of Technology and Economics Budafoki ut 8 1111 Budapest Hungary
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
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8
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Tan X, Ji K, Wang X, Yao R, Han G, Villamena FA, Zweier JL, Song Y, Rockenbauer A, Liu Y. Discriminative Detection of Biothiols by Electron Paramagnetic Resonance Spectroscopy using a Methanethiosulfonate Trityl Probe. Angew Chem Int Ed Engl 2019; 59:928-934. [PMID: 31657108 DOI: 10.1002/anie.201912832] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Indexed: 12/30/2022]
Abstract
Biothiols, such as glutathione (GSH), homocysteine (Hcy), and cysteine (Cys), coexist in biological systems with diverse biological roles. Thus, analytical techniques that can detect, quantify, and distinguish between multiple biothiols are desirable but challenging. Herein, we demonstrate the simultaneous detection and quantitation of multiple biothiols, including up to three different biothiols in a single sample, using electron paramagnetic resonance (EPR) spectroscopy and a trityl-radical-based probe (MTST). We term this technique EPR thiol-trapping. MTST could trap thiols through its methanethiosulfonate group to form the corresponding disulfide conjugate with an EPR spectrum characteristic of the trapped thiol. MTST was used to investigate effects of l-buthionine sulfoximine (BSO) and pyrrolidine dithiocarbamate (PDTC) on the efflux of GSH and Cys from HepG2 cells.
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Affiliation(s)
- Xiaoli Tan
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Kaiyun Ji
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Xing Wang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Ru Yao
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Guifang Han
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Frederick A Villamena
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Jay L Zweier
- Center for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung Research Institute, the Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Antal Rockenbauer
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117, Budapest, Hungary.,Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111, Budapest, Hungary
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
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Li Y, Zhai W, Liao Y, Nie J, Han G, Song Y, Li S, Hou J, Liu Y. Synthesis of Central Chirality-Containing Triarylmethanols and Triarylmethyl Radicals with Extraordinarily Stable Configurations. J Org Chem 2019; 84:11774-11782. [PMID: 31454244 DOI: 10.1021/acs.joc.9b01675] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Triarylmethanol adopts a propeller-shaped conformation with either right-handed (P) or left-handed (M) configuration. Herein, new triarylmethanols with two chiral centers were obtained via introduction of two cis-hydroxyl groups on the side chains, affording four stereoisomers. These four stereoisomers were easily separated by silica gel column chromatography into two pairs of propeller-shaped enantiomers, as shown by NMR and X-ray crystallographic studies. High-performance liquid chromatography (HPLC) studies showed that the configurations of the hydroxyl-bearing triarylmethanols are much more stable than those of the bulky tert-butyldimethylsilyl-protected precursors, inconsistent with the general strategy in which the steric repulsion is largely responsible for the configurational stability. Similarly, two hydroxyl-bearing tetrathiatriarylmethyl (TAM) radicals also exhibit excellent configurational stability and are thus separable by CS-HPLC into four stereoisomers. Interestingly, both helical chirality from triaryl group (M or P) and central chirality (R and S) on the side chain have little effect on their electron paramagnetic resonance properties. Our present study provides a new strategy to construct configurationally stable triaryl compounds and demonstrates that the side chain on TAM radicals is a new site for their structural modifications.
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Affiliation(s)
- Yingchun Li
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
| | - Weixiang Zhai
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
| | - Yongfang Liao
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
| | - Jiangping Nie
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
| | - Guifang Han
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
| | - Shaoyong Li
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
| | - Jingli Hou
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China
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10
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Site Selective and Efficient Spin Labeling of Proteins with a Maleimide-Functionalized Trityl Radical for Pulsed Dipolar EPR Spectroscopy. Molecules 2019; 24:molecules24152735. [PMID: 31357628 PMCID: PMC6696014 DOI: 10.3390/molecules24152735] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 01/18/2023] Open
Abstract
Pulsed dipolar electron paramagnetic resonance spectroscopy (PDS) in combination with site-directed spin labeling (SDSL) of proteins and oligonucleotides is a powerful tool in structural biology. Instead of using the commonly employed gem-dimethyl-nitroxide labels, triarylmethyl (trityl) spin labels enable such studies at room temperature, within the cells and with single-frequency electron paramagnetic resonance (EPR) experiments. However, it has been repeatedly reported that labeling of proteins with trityl radicals led to low labeling efficiencies, unspecific labeling and label aggregation. Therefore, this work introduces the synthesis and characterization of a maleimide-functionalized trityl spin label and its corresponding labeling protocol for cysteine residues in proteins. The label is highly cysteine-selective, provides high labeling efficiencies and outperforms the previously employed methanethiosulfonate-functionalized trityl label. Finally, the new label is successfully tested in PDS measurements on a set of doubly labeled Yersinia outer protein O (YopO) mutants.
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11
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Li C, Huang Z, Gao N, Zheng J, Guan J. Injectable, thermosensitive, fast gelation, bioeliminable, and oxygen sensitive hydrogels. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 99:1191-1198. [PMID: 30889653 PMCID: PMC7368179 DOI: 10.1016/j.msec.2019.02.075] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/06/2019] [Accepted: 02/20/2019] [Indexed: 01/09/2023]
Abstract
The decrease of tissue oxygen content due to pathological conditions leads to severe cell death and tissue damage. Restoration of tissue oxygen content is the primary treatment goal. To accurately and efficiently assess efficacy of a treatment, minimally invasive, and long-term detection of oxygen concentration in the same tissue location represents a clinically attractive strategy. Among the different oxygen concentration measurement approaches, electron paramagnetic resonance (EPR) has the potential to accomplish this. Yet there lacks injectable EPR probes that can maintain a consistent concentration at the same tissue location during treatment period to acquire a stable EPR signal, and can finally be eliminated from body without retrieval. Herein, we developed injectable and bioeliminable hydrogel-based polymeric EPR probes that exhibited fast gelation rate, slow weight loss rate, and high oxygen sensitivity. The probe was based on N-Isopropylacrylamide (NIPAAm), 2-hydroxyethyl methacrylate (HEMA), dimethyl-γ-butyrolactone acrylate (DBA), and tetrathiatriarylmethyl (TAM) radical. The injectable probes can be implanted into tissues using a minimally invasive injection approach. The high gelation rate (~10 s) allowed the probes to quickly solidify upon injection to have a high retention in tissues. The polymeric probes overcame the toxicity issue of current small molecule EPR probes. The probes can be gradually hydrolyzed. Upon complete hydrolysis, the probes became water soluble at 37 °C, thus having the potential to be removed from the body by urinary system. The probes showed slow weight loss rate so as to maintain EPR signal intensity for extended periods while retaining in a certain tissue location. The probes remained their high oxygen sensitivity after in vitro hydrolysis and in vivo implantation for 4 weeks. These hydrogel-based EPR probes have attractive properties for in vivo oxygen detection.
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Affiliation(s)
- Chao Li
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Zheng Huang
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Ning Gao
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA; Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jie Zheng
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jianjun Guan
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA; Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO 63130, USA.
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12
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Qu Y, Li Y, Tan X, Zhai W, Han G, Hou J, Liu G, Song Y, Liu Y. Synthesis and Characterization of Hydrophilic Trityl Radical TFO for Biomedical and Biophysical Applications. Chemistry 2019; 25:7888-7895. [PMID: 30972843 DOI: 10.1002/chem.201900262] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Indexed: 12/18/2022]
Abstract
Tetrathiatriarylmethyl (TAM, trityl) radicals have found wide applications as spin probes/labels for EPR spectroscopy and imaging, and as polarizing agents for dynamic nuclear polarization. The high hydrophilicity of TAM radicals is essential for their biomedical applications. However, the synthesis of hydrophilic TAM radicals (e.g., OX063) is extremely challenging and has only been reported in the patent literature, to date. Herein, an efficient synthesis of a highly water-soluble TAM radical bis(8-carboxyl-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']bis([1,3]dithiol-4-yl)-mono-(8-carboxyl-2,2,6,6-tetrakis(2-hydroxyethyl)benzo[1,2-d:4,5-d']bis([1,3]dithiol-4-yl)methyl (TFO), which contains four additional hydroxylethyl groups, relative to the Finland trityl radical CT-03, is reported. Similar to OX063, TFO exhibits excellent properties, including high water solubility in phosphate buffer, low log P, low pKa , long relaxation times, and negligible binding with bovine serum albumin. On the other hand, TFO has a sharper EPR line and higher O2 sensitivity than those of OX063. Therefore, in combination with its facile synthesis, TFO should find wide applications in magnetic resonance related fields and this synthetic approach would shed new light on the synthesis of other hydrophilic TAM radicals.
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Affiliation(s)
- Yuying Qu
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P.R. China
| | - Yingchun Li
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P.R. China
| | - Xiaoli Tan
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P.R. China
| | - Weixiang Zhai
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P.R. China
| | - Guifang Han
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P.R. China
| | - Jingli Hou
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P.R. China
| | - Guoquan Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, P.R. China
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P.R. China
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P.R. China
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13
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Hintz H, Vanas A, Klose D, Jeschke G, Godt A. Trityl Radicals with a Combination of the Orthogonal Functional Groups Ethyne and Carboxyl: Synthesis without a Statistical Step and EPR Characterization. J Org Chem 2019; 84:3304-3320. [DOI: 10.1021/acs.joc.8b03234] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Henrik Hintz
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
| | - Agathe Vanas
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Daniel Klose
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Adelheid Godt
- Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
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14
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Giannoulis A, Yang Y, Gong YJ, Tan X, Feintuch A, Carmieli R, Bahrenberg T, Liu Y, Su XC, Goldfarb D. DEER distance measurements on trityl/trityl and Gd(iii)/trityl labelled proteins. Phys Chem Chem Phys 2019; 21:10217-10227. [DOI: 10.1039/c8cp07249c] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Trityl–trityl and trityl–Gd(iii) DEER distance measurements in proteins are performed using a new trityl spin label affording thioether–protein conjugation.
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Affiliation(s)
- Angeliki Giannoulis
- Department of Chemical and Biological Physics
- Weizmann Institute of Science
- Rehovot 76100
- Israel
| | - Yin Yang
- Department of Chemical and Biological Physics
- Weizmann Institute of Science
- Rehovot 76100
- Israel
| | - Yan-Jun Gong
- State Key Laboratory of Elemento-organic Chemistry
- Collaborative Innovation Center of Chemical Science and Engineering
- Nankai University
- Tianjin 300071
- China
| | - Xiaoli Tan
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics
- School of Pharmacy
- Tianjin Medical University
- Tianjin 300070
- China
| | - Akiva Feintuch
- Department of Chemical and Biological Physics
- Weizmann Institute of Science
- Rehovot 76100
- Israel
| | - Raanan Carmieli
- Department of Chemical Research Support
- Weizmann Institute of Science
- Rehovot 76100
- Israel
| | - Thorsten Bahrenberg
- Department of Chemical and Biological Physics
- Weizmann Institute of Science
- Rehovot 76100
- Israel
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics
- School of Pharmacy
- Tianjin Medical University
- Tianjin 300070
- China
| | - Xun-Cheng Su
- State Key Laboratory of Elemento-organic Chemistry
- Collaborative Innovation Center of Chemical Science and Engineering
- Nankai University
- Tianjin 300071
- China
| | - Daniella Goldfarb
- Department of Chemical and Biological Physics
- Weizmann Institute of Science
- Rehovot 76100
- Israel
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15
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Zhai W, Feng Y, Liu H, Rockenbauer A, Mance D, Li S, Song Y, Baldus M, Liu Y. Diastereoisomers of l-proline-linked trityl-nitroxide biradicals: synthesis and effect of chiral configurations on exchange interactions. Chem Sci 2018; 9:4381-4391. [PMID: 29896379 PMCID: PMC5958346 DOI: 10.1039/c8sc00969d] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/05/2018] [Indexed: 01/08/2023] Open
Abstract
The chiral configuration of the two radical parts is a crucial factor controlling the exchange interactions and DNP properties of trityl-nitroxide biradicals.
The exchange (J) interaction of organic biradicals is a crucial factor controlling their physiochemical properties and potential applications and can be modulated by changing the nature of the linker. In the present work, we for the first time demonstrate the effect of chiral configurations of radical parts on the J values of trityl-nitroxide (TN) biradicals. Four diastereoisomers (TNT1, TNT2, TNL1 and TNL2) of TN biradicals were synthesized and purified by the conjugation of a racemic (R/S) nitroxide with the racemic (M/P) trityl radical vial-proline. The absolute configurations of these diastereoisomers were assigned by comparing experimental and calculated electronic circular dichroism (ECD) spectra as (M, S, S) for TNT1, (P, S, S) for TNT2, (M, S, R) for TNL1 and (P, S, R) for TNL2. Electron paramagnetic resonance (EPR) results showed that the configuration of the nitroxide part instead of the trityl part is dominant in controlling the exchange interactions and the order of the J values at room temperature is TNT1 (252 G) > TNT2 (127 G) ≫ TNL2 (33 G) > TNL1 (14 G). Moreover, the J values of TNL1/TNL2 with the S configuration in the nitroxide part vary with temperature and the polarity of solvents due to their flexible linker, whereas the J values of TNT1/TNT2 are almost insensitive to these two factors due to the rigidity of their linkers. The distinct exchange interactions between TNT1,2 and TNL1,2 in the frozen state led to strongly different high-field dynamic nuclear polarization (DNP) enhancements with ε = 7 for TNT1,2 and 40 for TNL1,2 under 800 MHz DNP conditions.
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Affiliation(s)
- Weixiang Zhai
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics , School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China . ;
| | - Yalan Feng
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics , School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China . ;
| | - Huiqiang Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics , School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China . ;
| | - Antal Rockenbauer
- Institute of Materials and Environmental Chemistry , Hungarian Academy of Sciences , Department of Physics , Budapest University of Technology and Economics , Budafoki ut 8 , 1111 Budapest , Hungary .
| | - Deni Mance
- NMR Spectroscopy , Bijvoet Center for Biomolecular Research , Utrecht University , 3584 CH Utrecht , The Netherlands
| | - Shaoyong Li
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics , School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China . ;
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics , School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China . ;
| | - Marc Baldus
- NMR Spectroscopy , Bijvoet Center for Biomolecular Research , Utrecht University , 3584 CH Utrecht , The Netherlands
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics , School of Pharmacy , Tianjin Medical University , Tianjin 300070 , P. R. China . ;
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16
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Fleck N, Schnakenburg G, Filippou AC, Schiemann O. Tris[2,2,6,6-tetra-methyl-8-(tri-methyl-sil-yl)benzo[1,2- d;4,5- d']bis-(1,3-di-thiol)-4-yl]methanol diethyl ether monosolvate. Acta Crystallogr E Crystallogr Commun 2018; 74:539-542. [PMID: 29765762 PMCID: PMC5946984 DOI: 10.1107/s2056989018004516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 03/17/2018] [Indexed: 11/20/2022]
Abstract
The title compound, a tri-aryl-methanol, C46H64OS12Si31, was synthesized via li-thia-tion of tris-2,2,6,6-tetra-methyl-benzo[1,2-d;4,5-d']bis-[1,3]di-thiol-4-yl-methanol, 2, and electrophilic quenching with tri-methyl-silyl chloride. The current crystal structure reveals information about the reactivity of this compound and compares well with the structure reported for the unsubstituted parent compound 2 [Driesschaert et al. (2012 ▸). Eur. J. Org. Chem.33, 6517-6525]. The title compound 1 forms mol-ecular propellers and crystallizes in P [Formula: see text], featuring an unusually long Si-Car bond of 1.910 (3) Å. Moreover, the geometry at the central quaternary carbon is rather trigonal-pyramidal than tetra-hedral due to vast intra-molecular stress. One tri-methyl-silyl group is disordered over two positions in a 0.504 (4):0.496 (4) ratio and one S atom is disordered over two positions in a 0.509 (7):0.491 (7) ratio. The contribution of disordered diethyl ether solvent mol-ecule(s) was removed using the PLATON SQUEEZE (Spek, 2015 ▸) solvent masking procedure. These solvent mol-ecules are not considered in the given chemical formula and other crystal data.
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Affiliation(s)
- Nico Fleck
- University of Bonn, Institute of Physical and Theoretical Chemistry, Wegelerstrasse 12, 53115 Bonn, Germany
| | - Gregor Schnakenburg
- University of Bonn, Institute of Inorganic Chemistry, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Alexander C. Filippou
- University of Bonn, Institute of Inorganic Chemistry, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Olav Schiemann
- University of Bonn, Institute of Physical and Theoretical Chemistry, Wegelerstrasse 12, 53115 Bonn, Germany
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17
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Jassoy JJ, Meyer A, Spicher S, Wuebben C, Schiemann O. Synthesis of Nanometer Sized Bis- and Tris-trityl Model Compounds with Different Extent of Spin-Spin Coupling. Molecules 2018; 23:E682. [PMID: 29562622 PMCID: PMC6017437 DOI: 10.3390/molecules23030682] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/12/2018] [Accepted: 03/16/2018] [Indexed: 12/29/2022] Open
Abstract
Tris(2,3,5,6-tetrathiaaryl)methyl radicals, so-called trityl radicals, are emerging as spin labels for distance measurements in biological systems based on Electron Paramagnetic Resonance (EPR). Here, the synthesis and characterization of rigid model systems carrying either two or three trityl moieties is reported. The monofunctionalized trityl radicals are connected to the molecular bridging scaffold via an esterification reaction employing the Mukaiyama reagent 2-chloro-methylpyridinium iodide. The bis- and tris-trityl compounds exhibit different inter-spin distances, strength of electron-electron exchange and dipolar coupling and can give rise to multi-spin effects. They are to serve as benchmark systems in comparing EPR distance measurement methods.
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Affiliation(s)
- J Jacques Jassoy
- Institute of Physical and Theoretical Chemistry, University of Bonn, 53115 Bonn, Germany.
| | - Andreas Meyer
- Institute of Physical and Theoretical Chemistry, University of Bonn, 53115 Bonn, Germany.
| | - Sebastian Spicher
- Institute of Physical and Theoretical Chemistry, University of Bonn, 53115 Bonn, Germany.
| | - Christine Wuebben
- Institute of Physical and Theoretical Chemistry, University of Bonn, 53115 Bonn, Germany.
| | - Olav Schiemann
- Institute of Physical and Theoretical Chemistry, University of Bonn, 53115 Bonn, Germany.
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18
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Tan X, Chen L, Song Y, Rockenbauer A, Villamena FA, Zweier JL, Liu Y. Thiol-Dependent Reduction of the Triester and Triamide Derivatives of Finland Trityl Radical Triggers O2-Dependent Superoxide Production. Chem Res Toxicol 2017; 30:1664-1672. [DOI: 10.1021/acs.chemrestox.7b00086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Xiaoli Tan
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Li Chen
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Yuguang Song
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Antal Rockenbauer
- Institute
of Materials and Environmental Chemistry, Hungarian Academy of Sciences,
Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111 Budapest, Hungary
| | - Frederick A. Villamena
- Department
of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jay L. Zweier
- Center
for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung
Research Institute, The Division of Cardiovascular Medicine, Department
of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Yangping Liu
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
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19
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Lawless MJ, Shimshi A, Cunningham TF, Kinde MN, Tang P, Saxena S. Analysis of Nitroxide-Based Distance Measurements in Cell Extracts and in Cells by Pulsed ESR Spectroscopy. Chemphyschem 2017; 18:1653-1660. [PMID: 28295910 DOI: 10.1002/cphc.201700115] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Indexed: 11/10/2022]
Abstract
Measurements of distances in cells by pulsed ESR spectroscopy afford tremendous opportunities to study proteins in native environments that are irreproducible in vitro. However, the in-cell environment is harsh towards the typical nitroxide radicals used in double electron-electron resonance (DEER) experiments. A systematic examination is performed on the loss of the DEER signal, including contributions from nitroxide decay and nitroxide side-chain cleavage. In addition, the possibility of extending the lifetime of the nitroxide radical by use of an oxidizing agent is investigated. Using this oxidizing agent, DEER distance measurements are performed on doubly nitroxide-labeled GB1, the immunoglobulin-binding domain of protein G, at varying incubation times in the cellular environment. It is found that, by comparison of the loss of DEER signal to the loss of the CW spectrum, cleavage of the nitroxide side chain contributes to the loss of DEER signal, which is significantly greater in cells than in cell extracts. Finally, local spin concentrations are monitored at varying incubation times to show the time required for molecular diffusion of a small globular protein within the cellular milieu.
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Affiliation(s)
- Matthew J Lawless
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA, 15260, USA
| | - Amit Shimshi
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA, 15260, USA
| | - Timothy F Cunningham
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA, 15260, USA.,Current address: Department of Chemistry, Hanover College, 484 Ball Dr, Hanover, IN, 47243, USA
| | - Monica N Kinde
- Department of Anesthesiology, University of Pittsburgh School of Medicine, 3501 5th Avenue, Pittsburgh, PA, 15213, USA.,Current address: Division of Basic Sciences, Kansas City University of Medicine and Biosciences, 2901 St. John's Blvd., Joplin, MO, 64804, USA
| | - Pei Tang
- Department of Anesthesiology, University of Pittsburgh School of Medicine, 3501 5th Avenue, Pittsburgh, PA, 15213, USA
| | - Sunil Saxena
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA, 15260, USA
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20
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Kuzhelev AA, Tormyshev VM, Rogozhnikova OY, Trukhin DV, Troitskaya TI, Strizhakov RK, Krumkacheva OA, Fedin MV, Bagryanskaya EG. Triarylmethyl Radicals: EPR Study of 13C Hyperfine Coupling Constants. Z PHYS CHEM 2017; 231:777-794. [PMID: 28539703 PMCID: PMC5439964 DOI: 10.1515/zpch-2016-0811] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Triarylmethyl (TAM) radicals are widely used in Electron Paramagnetic Resonance (EPR) spectroscopy as spin labels and in EPR imaging as spin probes for in vivo oxymetry. One of the key advantages of TAMs is extremely narrow EPR line, especially in case of deuterated analogues (~5 μT). Another advantage is their slow spin relaxation even at physiological temperatures allowing, in particular, application of pulsed dipolar EPR methods for distance measurements in biomolecules. In this paper a large series of TAM radicals and their deuterated analogues is synthesized, and corresponding spectroscopic parameters including 13C hyperfine constants are obtained for the first time. The negligible dependence of 13C hyperfine constants on solvent, as well as on structure and number of substituents at para-C atoms of aromatic rings, has been found. In addition, we have demonstrated that 13C signals at natural abundance can be employed for successful room-temperature distance measurements using Pulsed Electron Double Resonance (PELDOR or DEER).
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Affiliation(s)
- Andrey A. Kuzhelev
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Victor M. Tormyshev
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Olga Yu. Rogozhnikova
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Dmitry V. Trukhin
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Tatiana I. Troitskaya
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Rodion K. Strizhakov
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
| | - Olesya A. Krumkacheva
- International Tomography Center SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Matvey V. Fedin
- International Tomography Center SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Elena G. Bagryanskaya
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
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21
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Liu W, Nie J, Tan X, Liu H, Yu N, Han G, Zhu Y, Villamena FA, Song Y, Zweier JL, Liu Y. Synthesis and Characterization of PEGylated Trityl Radicals: Effect of PEGylation on Physicochemical Properties. J Org Chem 2016; 82:588-596. [DOI: 10.1021/acs.joc.6b02590] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Wenbo Liu
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Jiangping Nie
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Xiaoli Tan
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Huiqiang Liu
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Nannan Yu
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Guifang Han
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Yutian Zhu
- State
Key
Laboratory of Polymer Physics and Chemistry, Changchun Institute of
Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Frederick A. Villamena
- Department
of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Yuguang Song
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
| | - Jay L. Zweier
- Center
for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung
Research Institute, the Division of Cardiovascular Medicine, Department
of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Yangping Liu
- Tianjin
Key Laboratory on Technologies Enabling Development of Clinical Therapeutics
and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, P. R. China
- Center
for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung
Research Institute, the Division of Cardiovascular Medicine, Department
of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, United States
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22
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Jassoy JJ, Berndhäuser A, Duthie F, Kühn SP, Hagelueken G, Schiemann O. Versatile Trityl Spin Labels for Nanometer Distance Measurements on Biomolecules In Vitro and within Cells. Angew Chem Int Ed Engl 2016; 56:177-181. [PMID: 27918126 DOI: 10.1002/anie.201609085] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/03/2016] [Indexed: 01/04/2023]
Abstract
Structure determination of biomacromolecules under in-cell conditions is a relevant yet challenging task. Electron paramagnetic resonance (EPR) distance measurements in combination with site-directed spin labeling (SDSL) are a valuable tool in this endeavor but the usually used nitroxide spin labels are not well-suited for in-cell measurements. In contrast, triarylmethyl (trityl) radicals are highly persistent, exhibit a long relaxation time and a narrow spectral width. Here, the synthesis of a versatile collection of trityl spin labels and their application in in vitro and in-cell trityl-iron distance measurements on a cytochrome P450 protein are described. The trityl labels show similar labeling efficiencies and better signal-to-noise ratios (SNR) as compared to the popular methanethiosulfonate spin label (MTSSL) and enabled a successful in-cell measurement.
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Affiliation(s)
- J Jacques Jassoy
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Andreas Berndhäuser
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Fraser Duthie
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Sebastian P Kühn
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Gregor Hagelueken
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Olav Schiemann
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
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23
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Jassoy JJ, Berndhäuser A, Duthie F, Kühn SP, Hagelueken G, Schiemann O. Versatile Trityl Spin Labels for Nanometer Distance Measurements on Biomolecules In Vitro and within Cells. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201609085] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- J. Jacques Jassoy
- Institute of Physical and Theoretical Chemistry University of Bonn Wegelerstr. 12 53115 Bonn Germany
| | - Andreas Berndhäuser
- Institute of Physical and Theoretical Chemistry University of Bonn Wegelerstr. 12 53115 Bonn Germany
| | - Fraser Duthie
- Institute of Physical and Theoretical Chemistry University of Bonn Wegelerstr. 12 53115 Bonn Germany
| | - Sebastian P. Kühn
- Institute of Physical and Theoretical Chemistry University of Bonn Wegelerstr. 12 53115 Bonn Germany
| | - Gregor Hagelueken
- Institute of Physical and Theoretical Chemistry University of Bonn Wegelerstr. 12 53115 Bonn Germany
| | - Olav Schiemann
- Institute of Physical and Theoretical Chemistry University of Bonn Wegelerstr. 12 53115 Bonn Germany
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24
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Dhimitruka I, Alzarie YA, Hemann C, Samouilov A, Zweier JL. Trityl radicals in perfluorocarbon emulsions as stable, sensitive, and biocompatible oximetry probes. Bioorg Med Chem Lett 2016; 26:5685-5688. [PMID: 27836400 DOI: 10.1016/j.bmcl.2016.10.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 10/20/2016] [Accepted: 10/21/2016] [Indexed: 10/20/2022]
Abstract
EPR oximetry with the use of trityl radicals can enable sensitive O2 measurement in biological cells and tissues. However, in vitro cellular and in vivo biological applications are limited by rapid trityl probe degradation or biological clearance and the need to enhance probe O2 sensitivity. We synthesized novel perfluorocarbon (PFC) emulsions, ∼200nm droplet size, containing esterified perchlorinated triphenyl methyl (PTM) radicals dispersed in physiological aqueous buffers. These formulations exhibit excellent EPR signal stability, over 20-fold greater than free PTM probes, with high oxygen sensitivity ∼17mG/mmHg enabling pO2 measurement in aqueous solutions or cell suspensions with sensitivity >0.5mmHg. Thus, PFC-PTM probes hold great promise to enable combined O2 delivery and sensing as needed to restore or enhance tissue oxygenation in disease.
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Affiliation(s)
- Ilirian Dhimitruka
- Department of Internal Medicine, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Yasmin Alsayed Alzarie
- Department of Internal Medicine, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Craig Hemann
- Department of Internal Medicine, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Alexandre Samouilov
- Department of Internal Medicine, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Jay L Zweier
- Department of Internal Medicine, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
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25
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Roser P, Schmidt MJ, Drescher M, Summerer D. Site-directed spin labeling of proteins for distance measurements in vitro and in cells. Org Biomol Chem 2016; 14:5468-76. [DOI: 10.1039/c6ob00473c] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We here review strategies for site-directed spin labeling (SDSL) of proteins and discuss their potential for EPR distance measurements to study protein function in vitro and in cells.
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Affiliation(s)
- P. Roser
- Department of Chemistry
- Zukunftskolleg
- and Konstanz Research School Chemical Biology
- University of Konstanz
- 78457 Konstanz
| | - M. J. Schmidt
- Department of Chemistry
- Zukunftskolleg
- and Konstanz Research School Chemical Biology
- University of Konstanz
- 78457 Konstanz
| | - M. Drescher
- Department of Chemistry
- Zukunftskolleg
- and Konstanz Research School Chemical Biology
- University of Konstanz
- 78457 Konstanz
| | - D. Summerer
- Department of Chemistry and Chemical Biology
- Technical University of Dortmund
- 44227 Dortmund
- Germany
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26
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Frank J, Elewa M, Said MM, El Shihawy HA, El-Sadek M, Müller D, Meister A, Hause G, Drescher S, Metz H, Imming P, Mäder K. Synthesis, Characterization, and Nanoencapsulation of Tetrathiatriarylmethyl and Tetrachlorotriarylmethyl (Trityl) Radical Derivatives—A Study To Advance Their Applicability as in Vivo EPR Oxygen Sensors. J Org Chem 2015; 80:6754-66. [PMID: 26020133 DOI: 10.1021/acs.joc.5b00918] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tissue oxygenation plays an important role in the pathophysiology of various diseases and is often a marker of prognosis and therapeutic response. EPR (ESR) is a suitable noninvasive oximetry technique. However, to reliably deploy soluble EPR probes as oxygen sensors in complex biological systems, there is still a need to investigate and improve their specificity, sensitivity, and stability. We reproducibly synthesized various derivatives of tetrathiatriarylmethyl and tetrachlorotriarylmethyl (trityl) radicals. Hydrophilic radicals were investigated in aqueous solution mimicking physiological conditions by, e.g., variation of viscosity and ionic strength. Their specificity was satisfactory, but the oxygen sensitivity was low. To enhance the capability of trityl radicals as oxygen sensors, encapsulation into oily core nanocapsules was performed. Thus, different lipophilic triesters were prepared and characterized in oily solution employing oils typically used in drug formulations, i.e., middle-chain triglycerides and isopropyl myristate. Our screening identified the deuterated ethyl ester of D-TAM (radical 13) to be suitable. It had an extremely narrow single EPR line under anoxic conditions and excellent oxygen sensitivity. After encapsulation, it retained its oxygen responsiveness and was protected against reduction by ascorbic acid. These biocompatible and highly sensitive nanosensors offer great potential for future EPR oximetry applications in preclinical research.
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Affiliation(s)
- Juliane Frank
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Marwa Elewa
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany.,‡Faculty of Pharmacy, Suez Canal University, P.O. 41522, Ismailia, Egypt
| | - Mohamed M Said
- ‡Faculty of Pharmacy, Suez Canal University, P.O. 41522, Ismailia, Egypt
| | - Hosam A El Shihawy
- ‡Faculty of Pharmacy, Suez Canal University, P.O. 41522, Ismailia, Egypt
| | | | - Diana Müller
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Annette Meister
- ⊥Center for Structure and Dynamics of Proteins (MZP), Biocenter Martin-Luther-Universität (MLU) Halle-Wittenberg, Weinbergweg 22, 06120 Halle (Saale), Germany
| | - Gerd Hause
- #Biocenter Martin-Luther-Universität (MLU) Halle-Wittenberg, Weinbergweg 22, 06120 Halle (Saale), Germany
| | - Simon Drescher
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Hendrik Metz
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Peter Imming
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Karsten Mäder
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
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27
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Jagtap AP, Krstic I, Kunjir NC, Hänsel R, Prisner TF, Sigurdsson ST. Sterically shielded spin labels for in-cell EPR spectroscopy: Analysis of stability in reducing environment. Free Radic Res 2014; 49:78-85. [DOI: 10.3109/10715762.2014.979409] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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28
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Shevelev GY, Krumkacheva OA, Lomzov AA, Kuzhelev AA, Rogozhnikova OY, Trukhin DV, Troitskaya TI, Tormyshev VM, Fedin MV, Pyshnyi DV, Bagryanskaya EG. Physiological-temperature distance measurement in nucleic acid using triarylmethyl-based spin labels and pulsed dipolar EPR spectroscopy. J Am Chem Soc 2014; 136:9874-7. [PMID: 24963806 DOI: 10.1021/ja505122n] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Resolving the nanometer-scale structure of biomolecules in natural conditions still remains a challenging task. We report the first distance measurement in nucleic acid at physiological temperature using electron paramagnetic resonance (EPR). The model 10-mer DNA duplex has been labeled with reactive forms of triarylmethyl radicals and then immobilized on a sorbent in water solution and investigated by double quantum coherence EPR. We succeeded in development of optimal triarylmethyl-based labels, approach for site-directed spin labeling and efficient immobilization procedure that, working together, allowed us to measure as long distances as ~4.6 nm with high accuracy at 310 K (37 °C).
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Affiliation(s)
- Georgiy Yu Shevelev
- Institute of Chemical Biology and Fundamental Medicine, §International Tomography Center, and #N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of the Sciences (SB RAS) , Novosibirsk 630090, Russia
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29
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Tormyshev VM, Rogozhnikova OY, Bowman MK, Trukhin DV, Troitskaya TI, Vasiliev VG, Shundrin LA, Halpern HJ. Preparation of Diversely Substituted Triarylmethyl Radicals by the Quenching of Tris(2,3,5,6-tetrathiaaryl)methyl Cations with C-, N-, P-, and S-Nucleophiles. European J Org Chem 2014; 2014:371-380. [PMID: 24883040 PMCID: PMC4038673 DOI: 10.1002/ejoc.201301161] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Indexed: 11/08/2022]
Abstract
C-, N-, P-, and S-nucleophiles reacted with symmetrical tris(2,3,5,6-tetrathiaaryl)methyl cations, generated from the corresponding triarylmethanols by strong acids, to give a variety of asymmetrical monosubstituted persistent triaryl-methyl (TAM) radicals as the major products. The only byproducts were symmetrical TAMs.
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Affiliation(s)
- Victor M. Tormyshev
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Acad. M.A. Lavrentjev Ave., Novosibirsk 630090, Russia, http://www.nioch.nsc.ru/eng/labs/mcg_e.htm
- Department of Natural Sciences, National Research University, Novosibirsk State University, 2 Pirogov St., Novosibirsk 630090, Russia
| | - Olga Yu. Rogozhnikova
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Acad. M.A. Lavrentjev Ave., Novosibirsk 630090, Russia, http://www.nioch.nsc.ru/eng/labs/mcg_e.htm
| | - Michael K. Bowman
- Department of Chemistry, The University of Alabama, Box 870336, Tuscaloosa, Alabama 35487-0336, USA
| | - Dmitry V. Trukhin
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Acad. M.A. Lavrentjev Ave., Novosibirsk 630090, Russia, http://www.nioch.nsc.ru/eng/labs/mcg_e.htm
| | - Tatiana I. Troitskaya
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Acad. M.A. Lavrentjev Ave., Novosibirsk 630090, Russia, http://www.nioch.nsc.ru/eng/labs/mcg_e.htm
| | - Vladimir G. Vasiliev
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Acad. M.A. Lavrentjev Ave., Novosibirsk 630090, Russia, http://www.nioch.nsc.ru/eng/labs/mcg_e.htm
| | - Leonid A. Shundrin
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Acad. M.A. Lavrentjev Ave., Novosibirsk 630090, Russia, http://www.nioch.nsc.ru/eng/labs/mcg_e.htm
| | - Howard J. Halpern
- The Center for EPR Imaging in vivo Physiology, Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL 60637, USA, http://epri.uchicago.edu/
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30
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Song Y, Liu Y, Liu W, Villamena FA, Zweier JL. Characterization of the Binding of the Finland Trityl Radical with Bovine Serum Albumin. RSC Adv 2014; 4:47649-47656. [PMID: 26257888 DOI: 10.1039/c4ra04616a] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Understanding the interactions of trityl radicals with proteins is required to expand their biomedical applications. In this work, we demonstrate that the Finland trityl radical CT-03 binds to bovine serum albumin (BSA) in aqueous solution. Upon binding with BSA, CT-03 exhibits a much broader electron paramagnetic resonance (EPR) signal and this line broadening can be reversed by proteolysis of the BSA. The binding induces a red-shift of the maximal UV-Vis absorbance wavelength of CT-03 around 470 nm, likely due to localization of CT-03 in the relatively hydrophobic region of the protein. The interaction between CT-03 and BSA is driven by a hydrophobic interaction with an estimated binding constant of 2.18 ×105 M-1 at 298 K. Furthermore, only one CT-03 is bound to each molecule of BSA and the binding site is determined to be the sub-domain IIA (Sudlow's site I). This protein binding of the trityl probe to albumin can be used to study the structure and function of albumin and also must be considered for its use as an in vivo imaging agent or spin label.
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Affiliation(s)
- Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China ; The Davis Heart and Lung Research Institute, the Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio43210, United States
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China ; The Davis Heart and Lung Research Institute, the Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio43210, United States
| | - Wenbo Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China
| | - Frederick A Villamena
- The Davis Heart and Lung Research Institute, the Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio43210, United States ; Department of Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jay L Zweier
- The Davis Heart and Lung Research Institute, the Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio43210, United States
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31
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Kunjir NC, Reginsson GW, Schiemann O, Sigurdsson ST. Measurements of short distances between trityl spin labels with CW EPR, DQC and PELDOR. Phys Chem Chem Phys 2013; 15:19673-85. [PMID: 24135783 DOI: 10.1039/c3cp52789a] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Trityl based spin labels are emerging as a complement to nitroxides in nanometer distance measurements using EPR methods. The narrow spectral width of the trityl radicals prompts us to ask the question at which distance between these spin centers, the pseudo-secular part of the dipolar coupling and spin density delocalization have to be taken into account. For this, two trityl-trityl and one trityl-nitroxide model compounds were synthesized with well-defined interspin distances. Continuous wave (CW) EPR, double quantum coherence (DQC) and pulsed electron-electron double resonance (PELDOR) spectra were acquired from these compounds at commercial X-band frequencies. The data analysis shows that two of the compounds, with distances of up to 25 Å, fall into the strong coupling regime and that precise distances can only be obtained if both the spin density delocalization and the pseudo-secular part of the dipolar coupling are included in the analysis.
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Affiliation(s)
- Nitin C Kunjir
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavík, Iceland.
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32
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Decroos C, Balland V, Boucher JL, Bertho G, Xu-Li Y, Mansuy D. Toward stable electron paramagnetic resonance oximetry probes: synthesis, characterization, and metabolic evaluation of new ester derivatives of a tris-(para-carboxyltetrathiaaryl)methyl (TAM) radical. Chem Res Toxicol 2013; 26:1561-9. [PMID: 24010758 DOI: 10.1021/tx400250a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tris(p-carboxyltetrathiaaryl)methyl (TAM) radicals, such as 1a ("Finland" radical), are useful EPR probes for oximetry. However, they are rapidly metabolized by liver microsomes in the presence of NADPH, with the formation of diamagnetic quinone-methide metabolites resulting from an oxidative decarboxylation of one of their carboxylate substituents. In an effort to obtain TAM derivatives potentially more metabolically stable in vivo, we have synthesized four new TAM radicals in which the carboxylate substituents of 1a have been replaced with esters groups bearing various alkyl chains designed to render them water-soluble. The new compounds were completely characterized by UV-vis and EPR spectroscopies, high resolution mass spectrometry (HRMS), and electrochemistry. Two of them were water-soluble enough to undergo detailed microsomal metabolic studies in comparison with 1a. They were found to be stable in the presence of the esterases present in rat liver microsomes and cytosol, and, contrary to 1a, stable to oxidation in the presence of NADPH-supplemented microsomes. A careful study of their possible microsomal reduction under anaerobic or aerobic conditions showed that they were more easily reduced than 1a, in agreement with their higher reduction potentials. They were reduced into the corresponding anions not only under anaerobic conditions but also in the presence of dioxygen. These anions were much more stable than that of 1a and could be characterized by UV-vis spectroscopy, MS, and at the level of their protonated product. However, they were oxidized by O₂, giving back to the starting ester radicals and catalyzing a futile cycle of O₂ reduction. Such reactions should be considered in the design of future stable EPR probes for oximetry in vivo.
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Affiliation(s)
- Christophe Decroos
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601 CNRS, Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75270 Paris, France
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33
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Müller D, Adelsberger K, Imming P. Organic Preparations with Molar Amounts of Volatile Malodorous Thiols. SYNTHETIC COMMUN 2013. [DOI: 10.1080/00397911.2011.640968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Diana Müller
- a Institut für Pharmazie, Martin-Luther-Universität , Halle , Germany
| | - Klaus Adelsberger
- b Luft- und Thermotechnik Bayreuth GmbH & Co. , Goldkronach , Germany
| | - Peter Imming
- a Institut für Pharmazie, Martin-Luther-Universität , Halle , Germany
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34
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Song Y, Liu Y, Hemann C, Villamena FA, Zweier JL. Esterified Dendritic TAM Radicals with Very High Stability and Enhanced Oxygen Sensitivity. J Org Chem 2013; 78:1371-6. [DOI: 10.1021/jo301849k] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Yuguang Song
- The
Davis Heart and Lung Research Institute, the Division of Cardiovascular
Medicine, Department of Internal Medicine, and‡Department of Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Yangping Liu
- The
Davis Heart and Lung Research Institute, the Division of Cardiovascular
Medicine, Department of Internal Medicine, and‡Department of Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Craig Hemann
- The
Davis Heart and Lung Research Institute, the Division of Cardiovascular
Medicine, Department of Internal Medicine, and‡Department of Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Frederick A. Villamena
- The
Davis Heart and Lung Research Institute, the Division of Cardiovascular
Medicine, Department of Internal Medicine, and‡Department of Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jay L. Zweier
- The
Davis Heart and Lung Research Institute, the Division of Cardiovascular
Medicine, Department of Internal Medicine, and‡Department of Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
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35
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Liu Y, Villamena FA, Rockenbauer A, Song Y, Zweier JL. Structural factors controlling the spin-spin exchange coupling: EPR spectroscopic studies of highly asymmetric trityl-nitroxide biradicals. J Am Chem Soc 2013; 135:2350-6. [PMID: 23320522 DOI: 10.1021/ja311571v] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Highly asymmetric exchange-coupled biradicals, e.g., the trityl-nitroxides (TNs), possess particular magnetic properties that have opened new possibilities for their application in biophysical, physicochemical, and biological studies. In the present work, we investigated the effect of the linker length on the spin-spin coupling interaction (J) in TN biradicals using the newly synthesized biradicals CT02-GT, CT02-AT, CT02-VT, and CT02-PPT as well as the previously reported biradicals TNN14 and TN1. The results show that the magnitude of J can be easily tuned from ~4 G (conformer 1 in CT02-PPT) to >1200 G (in TNN14) by varying the linker separating the two radical moieties and changing the temperature. Computer simulations of EPR spectra were carried out to estimate J values of the TN biradicals directly. In addition to the spin-spin coupling interaction of TN biradicals, their g, hyperfine-splitting, and zero-field-splitting interactions were explored at low temperature (220 K). Our present study clearly shows that varying the spin-spin interaction as a function of linker distance and temperature provides an effective strategy for the development of new TN biradicals that can find wide applications in relevant fields.
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Affiliation(s)
- Yangping Liu
- Center for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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36
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Liu Y, Song Y, De Pascali F, Liu X, Villamena FA, Zweier JL. Tetrathiatriarylmethyl radical with a single aromatic hydrogen as a highly sensitive and specific superoxide probe. Free Radic Biol Med 2012; 53:2081-2091. [PMID: 23000244 PMCID: PMC4118678 DOI: 10.1016/j.freeradbiomed.2012.09.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 09/04/2012] [Accepted: 09/13/2012] [Indexed: 01/09/2023]
Abstract
Superoxide (O(2)(•-)) plays crucial roles in normal physiology and disease; however, its measurement remains challenging because of the limited sensitivity and/or specificity of prior detection methods. We demonstrate that a tetrathiatriarylmethyl (TAM) radical with a single aromatic hydrogen (CT02-H) can serve as a highly sensitive and specific O(2)(•-) probe. CT02-H is an analogue of the fully substituted TAM radical CT-03 (Finland trityl) with an electron paramagnetic resonance (EPR) doublet signal due to its aromatic hydrogen. Owing to the neutral nature and negligible steric hindrance of the hydrogen, O(2)(•-) preferentially reacts with CT02-H at this site with production of the diamagnetic quinone methide via oxidative dehydrogenation. Upon reaction with O(2)(•-), CT02-H loses its EPR signal and this EPR signal decay can be used to quantitatively measure O(2)(•-). This is accompanied by a change in color from green to purple, with the quinone methide product exhibiting a unique UV-Vis absorbance (ε=15,900 M(-1) cm(-1)) at 540 nm, providing an additional O(2)(•-) detection method. More than five-fold higher reactivity of CT02-H for O(2)(•-) relative to CT-03 was demonstrated, with a second-order rate constant of 1.7×10(4) M(-1) s(-1) compared to 3.1×10(3) M(-1) s(-1) for CT-03. CT02-H exhibited high specificity for O(2)(•-) as evidenced by its inertness to other oxidoreductants. The O(2)(•-) generation rates detected by CT02-H from xanthine/xanthine oxidase were consistent with those measured by cytochrome c reduction but detection sensitivity was 10- to 100-fold higher. EPR detection of CT02-H enabled measurement of very low O(2)(•-) flux with a detection limit of 0.34 nM/min over 120 min. HPLC in tandem with electrochemical detection was used to quantitatively detect the stable quinone methide product and is a highly sensitive and specific method for measurement of O(2)(•-), with a sensitivity limit of ~2×10(-13) mol (10 nM with 20-μl injection volume). Based on the O(2)-dependent linewidth broadening of its EPR spectrum, CT02-H also enables simultaneous measurement of O(2) concentration and O(2)(•-) generation and was shown to provide sensitive detection of extracellular O(2)(•-) generation in endothelial cells stimulated either by menadione or with anoxia/reoxygenation. Thus, CT02-H is a unique probe that provides very high sensitivity and specificity for measurement of O(2)(•-) by either EPR or HPLC methods.
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Affiliation(s)
- Yangping Liu
- Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Yuguang Song
- Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Francesco De Pascali
- Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Xiaoping Liu
- Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Frederick A. Villamena
- Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
- Department of Pharmacology, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Jay L. Zweier
- Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
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37
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Reginsson GW, Kunjir NC, Sigurdsson ST, Schiemann O. Trityl radicals: spin labels for nanometer-distance measurements. Chemistry 2012; 18:13580-4. [PMID: 22996284 DOI: 10.1002/chem.201203014] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Indexed: 12/11/2022]
Abstract
Spin labelling with trityls: to gather information about the structure and dynamics of trityl radicals, spin-labelled polymers were measured with pulsed electron-electron double resonance (PELDOR) and double-quantum coherence (DQC). This study demonstrates that trityl radicals have great potential as spin labels that eliminate some limitations of nitroxide spin labels.
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Affiliation(s)
- Gunnar W Reginsson
- Biomedical Sciences Research Complex, Centre of Magnetic Resonance, St. Andrews, UK
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38
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Haze O, Corzilius B, Smith AA, Griffin RG, Swager TM. Water-soluble narrow-line radicals for dynamic nuclear polarization. J Am Chem Soc 2012; 134:14287-90. [PMID: 22917088 DOI: 10.1021/ja304918g] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of air-stable, highly water-soluble organic radicals containing a 1,3-bis(diphenylene)-2-phenylallyl (BDPA) core is reported. A sulfonated derivative, SA-BDPA, retains the narrow electron paramagnetic resonance linewidth (<30 MHz at 5 T) of the parent BDPA in highly concentrated glycerol/water solutions (40 mM), which enables its use as polarizing agent for solid effect dynamic nuclear polarization (SE DNP). A sensitivity enhancement of 110 was obtained in high-field magic-angle-spinning (MAS) NMR experiments. The ease of synthesis and high maximum enhancements obtained with the BDPA-based radicals constitute a major advance over the trityl-type narrow-line polarization agents.
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Affiliation(s)
- Olesya Haze
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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39
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Yang Z, Liu Y, Borbat P, Zweier JL, Freed JH, Hubbell WL. Pulsed ESR dipolar spectroscopy for distance measurements in immobilized spin labeled proteins in liquid solution. J Am Chem Soc 2012; 134:9950-2. [PMID: 22676043 PMCID: PMC3409244 DOI: 10.1021/ja303791p] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pulsed electron spin resonance (ESR) dipolar spectroscopy (PDS) in combination with site-directed spin labeling is unique in providing nanometer-range distances and distributions in biological systems. To date, most of the pulsed ESR techniques require frozen solutions at cryogenic temperatures to reduce the rapid electron spin relaxation rate and to prevent averaging of electron-electron dipolar interaction due to the rapid molecular tumbling. To enable measurements in liquid solution, we are exploring a triarylmethyl (TAM)-based spin label with a relatively long relaxation time where the protein is immobilized by attachment to a solid support. In this preliminary study, TAM radicals were attached via disulfide linkages to substituted cysteine residues at positions 65 and 80 or 65 and 76 in T4 lysozyme immobilized on Sepharose. Interspin distances determined using double quantum coherence (DQC) in solution are close to those expected from models, and the narrow distance distribution in each case indicates that the TAM-based spin label is relatively localized.
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Affiliation(s)
- Zhongyu Yang
- Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
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40
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Mesa JA, Velázquez-Palenzuela A, Brillas E, Coll J, Torres JL, Juliá L. Preparation and Characterization of Persistent Maltose-Conjugated Triphenylmethyl Radicals. J Org Chem 2012; 77:1081-6. [DOI: 10.1021/jo202356u] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Juan Antonio Mesa
- Departament de Química
Biològica i Modelització Molecular, Institut de Química Avançada de Catalunya (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
| | | | - Enric Brillas
- Departament de Química
Física, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Josep Coll
- Departament de Química
Biològica i Modelització Molecular, Institut de Química Avançada de Catalunya (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Josep Lluís Torres
- Departament de Química
Biològica i Modelització Molecular, Institut de Química Avançada de Catalunya (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Luis Juliá
- Departament de Química
Biològica i Modelització Molecular, Institut de Química Avançada de Catalunya (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
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41
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Tormyshev VM, Genaev AM, Sal'nikov GE, Rogozhnikova OY, Troitskaya TI, Trukhin DV, Mamatyuk VI, Fadeev DS, Halpern HJ. Triarylmethanols bearing bulky aryl groups and the NOESY/EXSY experimental observation of two-ring-flip mechanism for helicity reversal of molecular propellers. European J Org Chem 2011; 2012. [PMID: 24294110 DOI: 10.1002/ejoc.201101243] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Triarylmethanols - the direct precursors of persistent trityl radicals - are racemic mixtures of chiral three-bladed molecular propellers. Depending on bulkiness of aryl groups they exhibit various liabilities to interconversion, the half- life time of room temperature racemization varying in a range between 8.4 hours and 1.32 years. NOESY/EXSY experiment performed on two representative models strongly supports the two-ring flip mechanism for the configurational interchange.
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Affiliation(s)
- Victor M Tormyshev
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Acad. M.A. Lavrentjev Ave., Novosibirsk 630090, Russia ; Department of Natural Sciences, Novosibirsk State University, 2 Pirogov St., Novosibirsk 630090, Russia
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42
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Liu Y, Song Y, Rockenbauer A, Sun J, Hemann C, Villamena FA, Zweier JL. Synthesis of trityl radical-conjugated disulfide biradicals for measurement of thiol concentration. J Org Chem 2011; 76:3853-60. [PMID: 21488696 DOI: 10.1021/jo200265u] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Measurement of thiol concentrations is of great importance for characterizing their critical role in normal metabolism and disease. Low-frequency electron paramagnetic resonance (EPR) spectroscopy and imaging, coupled with the use of exogenous paramagnetic probes, have been indispensable techniques for the in vivo measurement of various physiological parameters owing to the specificity, noninvasiveness and good depth of magnetic field penetration in animal tissues. However, in vivo detection of thiol levels by EPR spectroscopy and imaging is limited due to the need for improved probes. We report the first synthesis of trityl radical-conjugated disulfide biradicals (TSSN and TSST) as paramagnetic thiol probes. The use of trityl radicals in the construction of these biradicals greatly facilitates thiol measurement by EPR spectroscopy since trityls have extraordinary stability in living tissues with a single narrow EPR line that enables high sensitivity and resolution for in vivo EPR spectroscopy and imaging. Both biradicals exhibit broad characteristic EPR spectra at room temperature because of their intramolecular spin-spin interaction. Reaction of these biradicals with thiol compounds such as glutathione (GSH) and cysteine results in the formation of trityl monoradicals which exhibit high spectral sensitivity to oxygen. The moderately slow reaction between the biradicals and GSH (k(2) ∼ 0.3 M(-1) s(-1) for TSSN and 0.2 M(-1) s(-1) for TSST) allows for in vivo measurement of GSH concentration without altering the redox environment in biological systems. The GSH concentration in rat liver was determined to be 3.49 ± 0.14 mM by TSSN and 3.67 ± 0.24 mM by TSST, consistent with the value (3.71 ± 0.09 mM) determined by the Ellman's reagent. Thus, these trityl-based thiol probes exhibit unique properties enabling measurement of thiols in biological systems and should be of great value for monitoring redox metabolism.
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Affiliation(s)
- Yangping Liu
- Center for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung Research Institute, the Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
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43
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Decroos C, Prangé T, Mansuy D, Boucher JL, Li Y. Unprecedented ipso aromatic nucleophilic substitution upon oxidative decarboxylation of tris(p-carboxyltetrathiaaryl)methyl (TAM) radicals: a new access to diversely substituted TAM radicals. Chem Commun (Camb) 2011; 47:4805-7. [PMID: 21412549 DOI: 10.1039/c1cc10426h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new reaction of oxidative substitution of aromatic carboxyl groups on stable trityl radical derivatives (TAMs) by various nucleophiles is described; it leads to a wide variety of new persistent and diversely substituted TAM radicals.
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Affiliation(s)
- Christophe Decroos
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, UMR 8601 CNRS, 45 Rue des Saints Pères, 75270 Paris cedex 06, France
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44
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Driesschaert B, Robiette R, Lucaccioni F, Gallez B, Marchand-Brynaert J. Chiral properties of tetrathiatriarylmethyl spin probes. Chem Commun (Camb) 2011; 47:4793-5. [DOI: 10.1039/c1cc10988j] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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45
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Liu Y, Villamena FA, Song Y, Sun J, Rockenbauer A, Zweier JL. Synthesis of 14N- and 15N-labeled trityl-nitroxide biradicals with strong spin-spin interaction and improved sensitivity to redox status and oxygen. J Org Chem 2010; 75:7796-802. [PMID: 21028905 DOI: 10.1021/jo1016844] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Simultaneous evaluation of redox status and oxygenation in biological systems is of great importance for the understanding of biological functions. Electron paramagnetic resonance (EPR) spectroscopy coupled with the use of the nitroxide radicals have been an indispensable technique for this application but are still limited by low oxygen sensitivity and low EPR resolution in part due to the moderately broad EPR triplet and spin quenching through bioreduction. In this study, we showed that these drawbacks can be overcome through the use of trityl-nitroxide biradicals allowing for the simultaneous measurement of redox status and oxygenation. A new trityl-nitroxide biradical TNN14 composed of a pyrrolidinyl-nitroxide and a trityl and its isotopically labeled (15)N analogue TNN15 were synthesized and characterized. Both biradicals exhibited much stronger spin-spin interaction with J > 400 G compared with that of the previous synthesized trityl-nitroxide biradicals TN1 (∼160 G) and TN2 (∼52 G) with longer linker chain length. The enhanced stability of TNN14 was evaluated using ascorbate as reductant, and the effect of different types of cyclodextrins on its stability in the presence of ascorbate was also investigated. Both biradicals are sensitive to redox status, and their corresponding trityl-hydroxylamines resulting from the reduction of the biradicals by ascorbate share the same oxygen sensitivity. Of note is that the (15)N-labeled TNN15-H with an EPR doublet exhibits improved EPR signal amplitude as compared with that of TNN14-H with an EPR triplet. In addition, cyclic voltammetric studies verify the characteristic electrochemical behaviors of the trityl-nitroxide biradicals.
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Affiliation(s)
- Yangping Liu
- Center for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung Research Institute, the Division of Cardiovascular Medicine, Department of Internal Medicine
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46
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Dane EL, Swager TM. Synthesis of a water-soluble 1,3-bis(diphenylene)-2-phenylallyl radical. J Org Chem 2010; 75:3533-6. [PMID: 20420445 DOI: 10.1021/jo100577g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The design and synthesis of a water-soluble 1,3-bis(diphenylene)-2-phenylallyl (BDPA) radical via the conjugate addition of a derivatized fluorene nucelophile is described. The compound is designed for use in dynamic nuclear polarization NMR. Its 9 GHz EPR spectrum in glycerol/water is reported.
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Affiliation(s)
- Eric L Dane
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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47
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Ahmad R, Kuppusamy P. Theory, instrumentation, and applications of electron paramagnetic resonance oximetry. Chem Rev 2010; 110:3212-36. [PMID: 20218670 PMCID: PMC2868962 DOI: 10.1021/cr900396q] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Rizwan Ahmad
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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48
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Dhimitruka I, Grigorieva O, Zweier JL, Khramtsov VV. Synthesis, structure, and EPR characterization of deuterated derivatives of Finland trityl radical. Bioorg Med Chem Lett 2010; 20:3946-9. [PMID: 20537895 DOI: 10.1016/j.bmcl.2010.05.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 05/04/2010] [Indexed: 02/09/2023]
Abstract
Substituted trityl radicals are important spin probes for functional electron paramagnetic resonance spectroscopy and imaging including oxygen and pH mapping in vivo. Here we report the synthetic procedure for large scale synthesis of deuterated Finland trityl radical with superior EPR spectral properties and higher sensitivity towards oxygen concentrations in solution. Additionally Finland trityl radicals substituted with linkers suitable for attaching peptide, or other synthetic precursors have been synthesized. The effect of deutero-substitution on EPR spectra of homologous derivatives has been evaluated. The compounds are potential candidates for targeted spin probes in EPR imaging.
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Affiliation(s)
- Ilirian Dhimitruka
- Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, 43210, USA
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49
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Liu Y, Villamena FA, Rockenbauer A, Zweier JL. Trityl-nitroxide biradicals as unique molecular probes for the simultaneous measurement of redox status and oxygenation. Chem Commun (Camb) 2009; 46:628-30. [PMID: 20062884 DOI: 10.1039/b919279d] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel trityl-nitroxide biradicals were synthesized and exhibited enhanced sensitivity and stability for rapid and simultaneous measurement of redox status and oxygenation by electron paramagnetic resonance spectroscopy.
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Affiliation(s)
- Yangping Liu
- Center for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung Research Institute, The Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
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50
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Bobko AA, Dhimitruka I, Eubank TD, Marsh CB, Zweier JL, Khramtsov VV. Trityl-based EPR probe with enhanced sensitivity to oxygen. Free Radic Biol Med 2009; 47:654-8. [PMID: 19523513 PMCID: PMC2739013 DOI: 10.1016/j.freeradbiomed.2009.06.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Revised: 06/03/2009] [Accepted: 06/05/2009] [Indexed: 11/27/2022]
Abstract
An asymmetric derivative of the triarylmethyl radical, TAM-H, containing one aldehyde and two carboxyl groups, was synthesized. The electron paramagnetic resonance (EPR) spectrum of TAM-H is characterized by a doublet of narrow lines with a linewidth of 105 mG under anoxic conditions and hyperfine interaction constant of 245 mG. The partial overlap of the components of the doublet results in enhanced sensitivity of the spectral amplitudes ratio to oxygen compared with oxygen-induced linewidth broadening of a single line. Application of the TAM-H probe allows for EPR measurements in an extended range of oxygen pressures from atmospheric to 1 mm Hg, whereas the EPR spectrum linewidth of the popular TAM-based oxygen sensor Oxo63 is practically insensitive to oxygen partial pressures below 20 mm Hg. Enhanced sensitivity of the TAM-H probe relative to Oxo63 was demonstrated in the detection of oxygen consumption by Met-1 cancer cells. The TAM-H probe allowed prolonged measurements of oxygen depletion during the hypoxia stage and down to true anoxia (<or=1.5 mm Hg).
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Affiliation(s)
- Andrey A Bobko
- Dorothy M. Davis Heart & Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
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