1
|
Lu C, Cho E, Cui Z, Gao Y, Cao W, Brédas JL, Coropceanu V, Li F. Towards Efficient and Stable Donor-Acceptor Luminescent Radicals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208190. [PMID: 36417767 DOI: 10.1002/adma.202208190] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/01/2022] [Indexed: 06/16/2023]
Abstract
In contrast to closed-shell luminescent molecules, the electronic ground state and lowest excited state in organic luminescent radicals are both spin doublet, which results in spin-allowed radiative transitions. Most reported luminescent radicals with high photoluminescent quantum efficiency (PLQE) have a donor-acceptor (D-A•) chemical structure where an electron-donating group is covalently attached to an electron-withdrawing radical core (A•). Understanding the main factors that define the efficiency and stability of D-A• type luminescent radicals remains challenging. Here, we designed and synthesized a series of tri(2,4,6-trichlorophenyl)methyl (TTM) radical derivatives with donor substituents varying by their extent of conjugation and their number of imine-type nitrogen atoms. The experimental results suggest that the luminescence efficiency and stability of the radicals are proportional to the degree of conjugation but inversely proportional to the number of imine nitrogen atoms in the substituents. These experimental trends are very well reproduced by density functional theory calculations. The theoretical results indicate that both the luminescence efficiency and radical stability are related to the energy difference between the charge transfer (CT) and local-excitation (LE) states, which decreases as either the number of imine nitrogen atoms in the substituent increases or its conjugation length decreases.
Collapse
Affiliation(s)
- Chen Lu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Eunkyung Cho
- Department of Chemistry and Biochemistry, University of Arizona College of Science, Tucson, AZ, 85721-0088, USA
| | - Zhiyuan Cui
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yuhang Gao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Wenjuan Cao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Jean-Luc Brédas
- Department of Chemistry and Biochemistry, University of Arizona College of Science, Tucson, AZ, 85721-0088, USA
| | - Veaceslav Coropceanu
- Department of Chemistry and Biochemistry, University of Arizona College of Science, Tucson, AZ, 85721-0088, USA
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| |
Collapse
|
2
|
Mentink-Vigier F, Dubroca T, Van Tol J, Sigurdsson ST. The distance between g-tensors of nitroxide biradicals governs MAS-DNP performance: The case of the bTurea family. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 329:107026. [PMID: 34246883 PMCID: PMC8316413 DOI: 10.1016/j.jmr.2021.107026] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/14/2021] [Accepted: 06/16/2021] [Indexed: 05/20/2023]
Abstract
Bis-nitroxide radicals are common polarizing agents (PA), used to enhance the sensitivity of solid-state NMR experiments via Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP). These biradicals can increase the proton spin polarization through the Cross-Effect (CE) mechanism, which requires PAs with at least two unpaired electrons. The relative orientation of the bis-nitroxide moieties is critical to ensure efficient polarization transfer. Recently, we have defined a new quantity, the distance between g-tensors, that correlates the relative orientation of the nitroxides with the ability to polarize the surrounding nuclei. Here we analyse experimentally and theoretically a series of biradicals belonging to the bTurea family, namely bcTol, AMUPol and bcTol-M. They differ by the degree of substitution on the urea bridge that connects the two nitroxides. Using quantitative simulations developed for moderate MAS frequencies, we show that these modifications mostly affect the relative orientations of the nitroxide, i.e. the length and distribution of the distance between the g-tensors, that in turn impacts both the steady state nuclear polarization/depolarization as well as the build-up times. The doubly substituted urea bridge favours a large distance between the g-tensors, which enables bcTol-M to provide ∊on/off>200 at 14.1 T/600 MHz/395 GHz with build-up times of 3.8 s using a standard homogenous solution. The methodology described herein was used to show how the conformation of the spirocyclic rings flanking the nitroxide function in the recently described c- and o-HydrOPol affects the distance between the g-tensors and thereby polarization performance.
Collapse
Affiliation(s)
- Frédéric Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, United States.
| | - Thierry Dubroca
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, United States
| | - Johan Van Tol
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, United States
| | | |
Collapse
|
3
|
Zaytseva EV, Mazhukin DG. Spirocyclic Nitroxides as Versatile Tools in Modern Natural Sciences: From Synthesis to Applications. Part I. Old and New Synthetic Approaches to Spirocyclic Nitroxyl Radicals. Molecules 2021; 26:677. [PMID: 33525514 PMCID: PMC7865516 DOI: 10.3390/molecules26030677] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/19/2021] [Accepted: 01/25/2021] [Indexed: 12/19/2022] Open
Abstract
Spirocyclic nitroxyl radicals (SNRs) are stable paramagnetics bearing spiro-junction at a-, b-, or g-carbon atom of the nitroxide fragment, which is part of the heterocyclic system. Despite the fact that the first representatives of SNRs were obtained about 50 years ago, the methodology of their synthesis and their usage in chemistry and biochemical applications have begun to develop rapidly only in the last two decades. Due to the presence of spiro-function in the SNRs molecules, the latter have increased stability to various reducing agents (including biogenic ones), while the structures of the biradicals (SNBRs) comprises a rigid spiro-fused core that fixes mutual position and orientation of nitroxide moieties that favors their use in dynamic nuclear polarization (DNP) experiments. This first review on SNRs will give a glance at various strategies for the synthesis of spiro-substituted, mono-, and bis-nitroxides on the base of six-membered (piperidine, 1,2,3,4-tetrahydroquinoline, 9,9'(10H,10H')-spirobiacridine, piperazine, and morpholine) or five-membered (2,5-dihydro-1H-pyrrole, pyrrolidine, 2,5-dihydro-1H-imidazole, 4,5-dihydro-1H-imidazole, imidazolidine, and oxazolidine) heterocyclic cores.
Collapse
Affiliation(s)
| | - Dmitrii G. Mazhukin
- Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences (SB RAS), Academician Lavrentiev Ave. 9, 630090 Novosibirsk, Russia;
| |
Collapse
|
4
|
EPR Spectroscopy: A Powerful Tool to Analyze Supramolecular Host•Guest Complexes of Stable Radicals with Cucurbiturils. Molecules 2020; 25:molecules25040776. [PMID: 32054033 PMCID: PMC7070855 DOI: 10.3390/molecules25040776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/01/2020] [Accepted: 02/07/2020] [Indexed: 01/22/2023] Open
Abstract
Stable organic free radicals are increasingly studied compounds due to the multiple and unusual properties imparted by the single electron(s). However, being paramagnetic, classical methods such as NMR spectroscopy can hardly be used due to relaxation and line broadening effects. EPR spectroscopy is thus better suited to get information about the immediate surroundings of the single electrons. EPR has enabled obtaining useful data in the context of host•guest chemistry, and a classical example is reported here for the stable (2,2,6,6-tetramethyl-4-oxo-piperidin-1-yl)oxyl or 4-oxo-TEMPO nitroxide (TEMPONE) inside the macrocycle host cucurbit[7]uril (CB[7]). Generally and also observed here, a contraction of the spectrum is observed as a result of the reduced nitrogen coupling constant due to inclusion complexation in the hydrophobic cavity of the host. Simulations of EPR spectra allowed determining the corresponding binding constant pointing to a weaker affinity for CB[7], compared to TEMPO with CB[7]. We complement this work by the results of EPR spectroscopy of a biradical: bis-TEMPO-bis-ketal (bTbk) with cucurbit[8]uril (CB[8]). Initial investigations pointed to very weak effects on the spectrum of the guest and incorrectly led us to conclude an absence of binding. However, simulations of EPR spectra combined with NMR data of reduced bTbk allowed showing inclusion complexation. EPR titrations were performed, and the corresponding binding constant was determined. 1H NMR spectra with reduced bTbk suggested a shuttle mechanism, at nearly one equivalent of CB[8], for which the host moves rapidly between two stations.
Collapse
|
5
|
Mentink-Vigier F. Optimizing nitroxide biradicals for cross-effect MAS-DNP: the role of g-tensors' distance. Phys Chem Chem Phys 2020; 22:3643-3652. [PMID: 31998899 DOI: 10.1039/c9cp06201g] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nitroxide biradicals are common polarizing agents used to enhance the sensitivity of solid-state NMR experiments via Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP). These biradicals are used to increase the polarization of protons through the cross-effect mechanism, which requires two unpaired electrons with a Larmor frequency difference greater than that of the protons. From their early conception, the relative orientation of the nitroxide rings has been identified as a critical factor determining their MAS-DNP performance. However, the MAS leads to a complex DNP mechanism with time dependent energy level anti-crossings making it difficult to pinpoint the role of relative g-tensor orientation. In this article, a single parameter called "g-tensors' distance" is introduced to characterize the relative orientation's impact on the MAS-DNP field profiles. It is demonstrated for the first time how the g-tensors' distance determines the nuclear hyperpolarization and depolarization properties of a given biradical. This provides a new critical parameter that paves the way for more efficient bis-nitroxides for MAS-DNP.
Collapse
Affiliation(s)
- Frédéric Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr, Tallahassee, FL 32310, USA.
| |
Collapse
|
6
|
Exploring Protein Structures by DNP-Enhanced Methyl Solid-State NMR Spectroscopy. J Am Chem Soc 2019; 141:19888-19901. [DOI: 10.1021/jacs.9b11195] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
7
|
Rankin AGM, Trébosc J, Pourpoint F, Amoureux JP, Lafon O. Recent developments in MAS DNP-NMR of materials. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 101:116-143. [PMID: 31189121 DOI: 10.1016/j.ssnmr.2019.05.009] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/21/2019] [Accepted: 05/21/2019] [Indexed: 05/03/2023]
Abstract
Solid-state NMR spectroscopy is a powerful technique for the characterization of the atomic-level structure and dynamics of materials. Nevertheless, the use of this technique is often limited by its lack of sensitivity, which can prevent the observation of surfaces, defects or insensitive isotopes. Dynamic Nuclear Polarization (DNP) has been shown to improve by one to three orders of magnitude the sensitivity of NMR experiments on materials under Magic-Angle Spinning (MAS), at static magnetic field B0 ≥ 5 T, conditions allowing for the acquisition of high-resolution spectra. The field of DNP-NMR spectroscopy of materials has undergone a rapid development in the last ten years, spurred notably by the availability of commercial DNP-NMR systems. We provide here an in-depth overview of MAS DNP-NMR studies of materials at high B0 field. After a historical perspective of DNP of materials, we describe the DNP transfers under MAS, the transport of polarization by spin diffusion and the various contributions to the overall sensitivity of DNP-NMR experiments. We discuss the design of tailored polarizing agents and the sample preparation in the case of materials. We present the DNP-NMR hardware and the influence of key experimental parameters, such as microwave power, magnetic field, temperature and MAS frequency. We give an overview of the isotopes that have been detected by this technique, and the NMR methods that have been combined with DNP. Finally, we show how MAS DNP-NMR has been applied to gain new insights into the structure of organic, hybrid and inorganic materials with applications in fields, such as health, energy, catalysis, optoelectronics etc.
Collapse
Affiliation(s)
- Andrew G M Rankin
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France
| | - Julien Trébosc
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Univ. Lille, CNRS-FR2638, Fédération Chevreul, F-59000 Lille, France
| | - Frédérique Pourpoint
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France
| | - Jean-Paul Amoureux
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Bruker Biospin, 34 rue de l'industrie, F-67166, Wissembourg, France
| | - Olivier Lafon
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Institut Universitaire de France, 1 rue Descartes, F-75231, Paris, France.
| |
Collapse
|
8
|
Mentink-Vigier F, Barra AL, van Tol J, Hediger S, Lee D, De Paëpe G. De novo prediction of cross-effect efficiency for magic angle spinning dynamic nuclear polarization. Phys Chem Chem Phys 2019; 21:2166-2176. [PMID: 30644474 DOI: 10.1039/c8cp06819d] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Magic angle spinning dynamic nuclear polarization (MAS-DNP) has become a key approach to boost the intrinsic low sensitivity of NMR in solids. This method relies on the use of both stable radicals as polarizing agents (PAs) and suitable high frequency microwave irradiation to hyperpolarize nuclei of interest. Relating PA chemical structure to DNP efficiency has been, and is still, a long-standing problem. The complexity of the polarization transfer mechanism has so far limited the impact of analytical derivation. However, recent numerical approaches have profoundly improved the basic understanding of the phenomenon and have now evolved to a point where they can be used to help design new PAs. In this work, the potential of advanced MAS-DNP simulations combined with DFT calculations and high-field EPR to qualitatively and quantitatively predict hyperpolarization efficiency of particular PAs is analyzed. This approach is demonstrated on AMUPol and TEKPol, two widely-used bis-nitroxide PAs. The results notably highlight how the PA structure and EPR characteristics affect the detailed shape of the DNP field profile. We also show that refined simulations of this profile using the orientation dependency of the electron spin-lattice relaxation times can be used to estimate the microwave B1 field experienced by the sample. Finally, we show how modelling the nuclear spin-lattice relaxation times of close and bulk nuclei while accounting for PA concentration allows for a prediction of DNP enhancement factors and hyperpolarization build-up times.
Collapse
|
9
|
Cui Z, Ye S, Wang L, Guo H, Obolda A, Dong S, Chen Y, Ai X, Abdurahman A, Zhang M, Wang L, Li F. Radical-Based Organic Light-Emitting Diodes with Maximum External Quantum Efficiency of 10.6. J Phys Chem Lett 2018; 9:6644-6648. [PMID: 30398056 DOI: 10.1021/acs.jpclett.8b03019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A new luminescent radical, tris-2,4,6-trichlorophenylmethyl-1,5-diazarcarbazole (TTM-DACz), was synthesized and characterized. The photoluminescence quantum yield of TTM-DACz in solid 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene matrix film (5 wt %) is as high as 57.0%. Organic light-emitting diodes (OLEDs) employing TTM-DACz as the emitter were fabricated. By rational design of the device structure and host-guest doping system, external quantum efficiency (EQE) of up to 10.6% of the optimized device with a red CIE chromaticity of (0.62, 0.36) was obtained, which is among the highest values for red OLEDs using nonphosphorescent materials as the emitters. This work will accelerate the development of luminescent radical materials for high-performance OLEDs.
Collapse
Affiliation(s)
- Zhiyuan Cui
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Shaofeng Ye
- Wuhan National Laboratory for Optoelectronics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Lu Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Haoqing Guo
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Ablikim Obolda
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Shengzhi Dong
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Yingxin Chen
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Xin Ai
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Alim Abdurahman
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Ming Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| | - Lei Wang
- Wuhan National Laboratory for Optoelectronics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , Qianjin Avenue 2699 , Changchun 130012 , P.R. China
| |
Collapse
|
10
|
Soetbeer J, Gast P, Walish JJ, Zhao Y, George C, Yang C, Swager TM, Griffin RG, Mathies G. Conformation of bis-nitroxide polarizing agents by multi-frequency EPR spectroscopy. Phys Chem Chem Phys 2018; 20:25506-25517. [PMID: 30277229 PMCID: PMC7256712 DOI: 10.1039/c8cp05236k] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The chemical structure of polarizing agents critically determines the efficiency of dynamic nuclear polarization (DNP). For cross-effect DNP, biradicals are the polarizing agents of choice and the interaction and relative orientation of the two unpaired electrons should be optimal. Both parameters are affected by the molecular structure of the biradical in the frozen glassy matrix that is typically used for DNP/MAS NMR and likely differs from the structure observed with X-ray crystallography. We have determined the conformations of six bis-nitroxide polarizing agents, including the highly efficient AMUPol, in their DNP matrix with EPR spectroscopy at 9.7 GHz, 140 GHz, and 275 GHz. The multi-frequency approach in combination with an advanced fitting routine allows us to reliably extract the interaction and relative orientation of the nitroxide moieties. We compare the structures of six bis-nitroxides to their DNP performance at 500 MHz/330 GHz.
Collapse
Affiliation(s)
- Janne Soetbeer
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Peter Gast
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
| | - Joseph J Walish
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yanchuan Zhao
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Christy George
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Chen Yang
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Timothy M Swager
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Robert G Griffin
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Guinevere Mathies
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
11
|
Jagtap AP, Geiger MA, Stöppler D, Orwick-Rydmark M, Oschkinat H, Sigurdsson ST. bcTol : a highly water-soluble biradical for efficient dynamic nuclear polarization of biomolecules. Chem Commun (Camb) 2018; 52:7020-3. [PMID: 27161650 DOI: 10.1039/c6cc01813k] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic nuclear polarization (DNP) is an efficient method to overcome the inherent low sensitivity of magic-angle spinning (MAS) solid-state NMR. We report a new polarizing agent (), designed for biological applications, that yielded an enhancement value of 244 in a microcrystalline SH3 domain sample at 110 K.
Collapse
Affiliation(s)
- Anil P Jagtap
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland.
| | - Michel-Andreas Geiger
- NMR supported structural biology, Leibniz-Institut for Molecular Biology (FMP), Robert-Roessle-Str. 10, 13125 Berlin, Germany.
| | - Daniel Stöppler
- NMR supported structural biology, Leibniz-Institut for Molecular Biology (FMP), Robert-Roessle-Str. 10, 13125 Berlin, Germany.
| | - Marcella Orwick-Rydmark
- NMR supported structural biology, Leibniz-Institut for Molecular Biology (FMP), Robert-Roessle-Str. 10, 13125 Berlin, Germany.
| | - Hartmut Oschkinat
- NMR supported structural biology, Leibniz-Institut for Molecular Biology (FMP), Robert-Roessle-Str. 10, 13125 Berlin, Germany.
| | - Snorri Th Sigurdsson
- University of Iceland, Department of Chemistry, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland.
| |
Collapse
|
12
|
Lilly Thankamony AS, Wittmann JJ, Kaushik M, Corzilius B. Dynamic nuclear polarization for sensitivity enhancement in modern solid-state NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 102-103:120-195. [PMID: 29157490 DOI: 10.1016/j.pnmrs.2017.06.002] [Citation(s) in RCA: 273] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/03/2017] [Accepted: 06/08/2017] [Indexed: 05/03/2023]
Abstract
The field of dynamic nuclear polarization has undergone tremendous developments and diversification since its inception more than 6 decades ago. In this review we provide an in-depth overview of the relevant topics involved in DNP-enhanced MAS NMR spectroscopy. This includes the theoretical description of DNP mechanisms as well as of the polarization transfer pathways that can lead to a uniform or selective spreading of polarization between nuclear spins. Furthermore, we cover historical and state-of-the art aspects of dedicated instrumentation, polarizing agents, and optimization techniques for efficient MAS DNP. Finally, we present an extensive overview on applications in the fields of structural biology and materials science, which underlines that MAS DNP has moved far beyond the proof-of-concept stage and has become an important tool for research in these fields.
Collapse
Affiliation(s)
- Aany Sofia Lilly Thankamony
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Johannes J Wittmann
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Monu Kaushik
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Björn Corzilius
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany.
| |
Collapse
|
13
|
Viger-Gravel J, Berruyer P, Gajan D, Basset JM, Lesage A, Tordo P, Ouari O, Emsley L. Frozen Acrylamide Gels as Dynamic Nuclear Polarization Matrices. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201703758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Jasmine Viger-Gravel
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); 1015 Lausanne Switzerland
| | - Pierrick Berruyer
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - David Gajan
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - Jean-Marie Basset
- King Abdullah University of Science and Technology (KAUST); KAUST Catalysis Center (KCC); Thuwal 23955-6900 Saudi Arabia
| | - Anne Lesage
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - Paul Tordo
- Aix Marseille Uni, CNRS, ICR UMR 7273; 13397 Marseille France
| | - Olivier Ouari
- Aix Marseille Uni, CNRS, ICR UMR 7273; 13397 Marseille France
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); 1015 Lausanne Switzerland
| |
Collapse
|
14
|
Frozen Acrylamide Gels as Dynamic Nuclear Polarization Matrices. Angew Chem Int Ed Engl 2017; 56:8726-8730. [DOI: 10.1002/anie.201703758] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Indexed: 01/08/2023]
|
15
|
Silverio DL, van Kalkeren HA, Ong TC, Baudin M, Yulikov M, Veyre L, Berruyer P, Chaudhari S, Gajan D, Baudouin D, Cavaillès M, Vuichoud B, Bornet A, Jeschke G, Bodenhausen G, Lesage A, Emsley L, Jannin S, Thieuleux C, Copéret C. Tailored Polarizing Hybrid Solids with Nitroxide Radicals Localized in Mesostructured Silica Walls. Helv Chim Acta 2017. [DOI: 10.1002/hlca.201700101] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Daniel L. Silverio
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| | - Henri A. van Kalkeren
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Ta-Chung Ong
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| | - Mathieu Baudin
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
- Laboratoire des Biomolécules (LBM); Département de Chimie, Ecole Normale Supérieure; UPMC Université Paris 06; CNRS; PSL Research University; 24 rue Lhomond FR-75005 Paris
- Laboratoire des Biomolécules (LBM); Sorbonne Universités; UPMC Université Paris 06; Ecole Normale Supérieure; CNRS; FR-75005 Paris
| | - Maxim Yulikov
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| | - Laurent Veyre
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Pierrick Berruyer
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - Sachin Chaudhari
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - David Gajan
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - David Baudouin
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Matthieu Cavaillès
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Basile Vuichoud
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
| | - Aurélien Bornet
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
| | - Gunnar Jeschke
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| | - Geoffrey Bodenhausen
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
- Laboratoire des Biomolécules (LBM); Département de Chimie, Ecole Normale Supérieure; UPMC Université Paris 06; CNRS; PSL Research University; 24 rue Lhomond FR-75005 Paris
- Laboratoire des Biomolécules (LBM); Sorbonne Universités; UPMC Université Paris 06; Ecole Normale Supérieure; CNRS; FR-75005 Paris
| | - Anne Lesage
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
| | - Sami Jannin
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - Chloé Thieuleux
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| |
Collapse
|
16
|
Rogawski R, Sergeyev IV, Li Y, Ottaviani MF, Cornish V, McDermott AE. Dynamic Nuclear Polarization Signal Enhancement with High-Affinity Biradical Tags. J Phys Chem B 2017; 121:1169-1175. [PMID: 28099013 DOI: 10.1021/acs.jpcb.6b09021] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Dynamic nuclear polarization is an emerging technique for sensitizing solid-state NMR experiments by transferring polarization from electrons to nuclei. Stable biradicals, the polarization source for the cross effect mechanism, are typically codissolved at millimolar concentrations with proteins of interest. Here we describe the high-affinity biradical tag TMP-T, created by covalently linking trimethoprim, a nanomolar affinity ligand of dihydrofolate reductase (DHFR), to the biradical polarizing agent TOTAPOL. With TMP-T bound to DHFR, large enhancements of the protein spectrum are observed, comparable to when TOTAPOL is codissolved with the protein. In contrast to TOTAPOL, the tight binding TMP-T can be added stoichiometrically at radical concentrations orders of magnitude lower than in previously described preparations. Benefits of the reduced radical concentration include reduced spectral bleaching, reduced chemical perturbation of the sample, and the ability to selectively enhance signals for the protein of interest.
Collapse
Affiliation(s)
- Rivkah Rogawski
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Ivan V Sergeyev
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Yongjun Li
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - M Francesca Ottaviani
- Department of Pure and Applied Sciences, University of Urbino , Loc. Crocicchia, 61029 Urbino, Italy
| | - Virginia Cornish
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Ann E McDermott
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| |
Collapse
|
17
|
Liao WC, Ong TC, Gajan D, Bernada F, Sauvée C, Yulikov M, Pucino M, Schowner R, Schwarzwälder M, Buchmeiser MR, Jeschke G, Tordo P, Ouari O, Lesage A, Emsley L, Copéret C. Dendritic polarizing agents for DNP SENS. Chem Sci 2017; 8:416-422. [PMID: 28451187 PMCID: PMC5365053 DOI: 10.1039/c6sc03139k] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 08/19/2016] [Indexed: 01/22/2023] Open
Abstract
Dendrimer-shielded polarizing agents for the application of DNP SENS to reactive surfaces.
Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy (DNP SENS) is an effective method to significantly improve solid-state NMR investigation of solid surfaces. The presence of unpaired electrons (polarizing agents) is crucial for DNP, but it has drawbacks such as leading to faster nuclear spin relaxation, or even reaction with the substrate under investigation. The latter can be a particular problem for heterogeneous catalysts. Here, we present a series of carbosilane-based dendritic polarizing agents, in which the bulky dendrimer can reduce the interaction between the solid surface and the free radical. We thereby preserve long nuclear T′2 of the surface species, and even successfully enhance a reactive heterogeneous metathesis catalyst.
Collapse
Affiliation(s)
- Wei-Chih Liao
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 1-5 , 8093 Zürich , Switzerland .
| | - Ta-Chung Ong
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 1-5 , 8093 Zürich , Switzerland .
| | - David Gajan
- Centre de RMN à Très Hauts Champs , Institut de Sciences Analytiques (CNRS/ENS Lyon/UCB Lyon 1) , Université de Lyon , 69100 Villeurbanne , France
| | - Florian Bernada
- Aix-Marseille Univ , CNRS , ICR UMR 7273 , Marseille , 13013 , France
| | - Claire Sauvée
- Aix-Marseille Univ , CNRS , ICR UMR 7273 , Marseille , 13013 , France
| | - Maxim Yulikov
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 1-5 , 8093 Zürich , Switzerland .
| | - Margherita Pucino
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 1-5 , 8093 Zürich , Switzerland .
| | - Roman Schowner
- Institut für Polymerchemie , Universität Stuttgart , Pfaffenwaldring 55 , D-70569 Stuttgart , Germany
| | - Martin Schwarzwälder
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 1-5 , 8093 Zürich , Switzerland .
| | - Michael R Buchmeiser
- Institut für Polymerchemie , Universität Stuttgart , Pfaffenwaldring 55 , D-70569 Stuttgart , Germany
| | - Gunnar Jeschke
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 1-5 , 8093 Zürich , Switzerland .
| | - Paul Tordo
- Aix-Marseille Univ , CNRS , ICR UMR 7273 , Marseille , 13013 , France
| | - Olivier Ouari
- Aix-Marseille Univ , CNRS , ICR UMR 7273 , Marseille , 13013 , France
| | - Anne Lesage
- Centre de RMN à Très Hauts Champs , Institut de Sciences Analytiques (CNRS/ENS Lyon/UCB Lyon 1) , Université de Lyon , 69100 Villeurbanne , France
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques , Ecole Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne , Switzerland
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 1-5 , 8093 Zürich , Switzerland .
| |
Collapse
|
18
|
Scott MJ, Billiar TR, Stoyanovsky DA. N-tert-butylmethanimine N-oxide is an efficient spin-trapping probe for EPR analysis of glutathione thiyl radical. Sci Rep 2016; 6:38773. [PMID: 27941944 PMCID: PMC5150238 DOI: 10.1038/srep38773] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/10/2016] [Indexed: 12/29/2022] Open
Abstract
The electron spin resonance (EPR) spin-trapping technique allows detection of radical species with nanosecond half-lives. This technique is based on the high rates of addition of radicals to nitrones or nitroso compounds (spin traps; STs). The paramagnetic nitroxides (spin-adducts) formed as a result of reactions between STs and radical species are relatively stable compounds whose EPR spectra represent “structural fingerprints” of the parent radical species. Herein we report a novel protocol for the synthesis of N-tert-butylmethanimine N-oxide (EBN), which is the simplest nitrone containing an α-H and a tertiary α′-C atom. We present EPR spin-trapping proof that: (i) EBN is an efficient probe for the analysis of glutathione thiyl radical (GS•); (ii) β-cyclodextrins increase the kinetic stability of the spin-adduct EBN/•SG; and (iii) in aqueous solutions, EBN does not react with superoxide anion radical (O2−•) to form EBN/•OOH to any significant extent. The data presented complement previous studies within the context of synthetic accessibility to EBN and efficient spin-trapping analysis of GS•.
Collapse
Affiliation(s)
- Melanie J Scott
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Detcho A Stoyanovsky
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
19
|
Kaur H, Lakatos A, Spadaccini R, Vogel R, Hoffmann C, Becker-Baldus J, Ouari O, Tordo P, Mchaourab H, Glaubitz C. The ABC exporter MsbA probed by solid state NMR – challenges and opportunities. Biol Chem 2016; 396:1135-49. [PMID: 25849794 DOI: 10.1515/hsz-2015-0119] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/26/2015] [Indexed: 01/20/2023]
Abstract
ATP binding cassette (ABC) transporters form a superfamily of integral membrane proteins involved in translocation of substrates across the membrane driven by ATP hydrolysis. Despite available crystal structures and extensive biochemical data, many open questions regarding their transport mechanisms remain. Therefore, there is a need to explore spectroscopic techniques such as solid state NMR in order to bridge the gap between structural and mechanistic data. In this study, we investigate the feasibility of using Escherichia coli MsbA as a model ABC transporter for solid state NMR studies. We show that optimised solubilisation and reconstitution procedures enable preparing stable and homogenous protein samples. Depending on the duration of solubilisation, MsbA can be obtained in either an apo- or in a native lipid A bound form. Building onto these optimisations, the first promising MAS-NMR spectra with narrow lines have been recorded. However, further sensitivity improvements are required so that complex NMR experiments can be recorded within a reasonable amount of time. We therefore demonstrate the usability of paramagnetic doping for rapid data acquisition and explore dynamic nuclear polarisation as a method for general signal enhancement. Our results demonstrate that solid state NMR provides an opportunity to address important biological questions related to complex mechanisms of ABC transporters.
Collapse
|
20
|
Sauvée C, Casano G, Abel S, Rockenbauer A, Akhmetzyanov D, Karoui H, Siri D, Aussenac F, Maas W, Weber RT, Prisner T, Rosay M, Tordo P, Ouari O. Tailoring of Polarizing Agents in the bTurea Series for Cross-Effect Dynamic Nuclear Polarization in Aqueous Media. Chemistry 2016; 22:5598-606. [PMID: 26992052 DOI: 10.1002/chem.201504693] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Indexed: 11/10/2022]
Abstract
A series of 18 nitroxide biradicals derived from bTurea has been prepared, and their enhancement factors ɛ ((1)H) in cross-effect dynamic nuclear polarization (CE DNP) NMR experiments at 9.4 and 14.1 T and 100 K in a DNP-optimized glycerol/water matrix ("DNP juice") have been studied. We observe that ɛ ((1)H) is strongly correlated with the substituents on the polarizing agents, and its trend is discussed in terms of different molecular parameters: solubility, average e-e distance, relative orientation of the nitroxide moieties, and electron spin relaxation times. We show that too short an e-e distance or too long a T1e can dramatically limit ɛ ((1)H). Our study also shows that the molecular structure of AMUPol is not optimal and its ɛ ((1)H) could be further improved through stronger interaction with the glassy matrix and a better orientation of the TEMPO moieties. A new AMUPol derivative introduced here provides a better ɛ ((1)H) than AMUPol itself (by a factor of ca. 1.2).
Collapse
Affiliation(s)
- Claire Sauvée
- Aix-Marseille Université, CNRS, ICR UMR 7273, 13397, Marseille cedex 20, France
| | - Gilles Casano
- Aix-Marseille Université, CNRS, ICR UMR 7273, 13397, Marseille cedex 20, France
| | - Sébastien Abel
- Aix-Marseille Université, CNRS, ICR UMR 7273, 13397, Marseille cedex 20, France
| | - Antal Rockenbauer
- Institute of Materials and Environmental Chemistry, Hungarian Academy of Sciences, Department of Physics, Budapest University of Technology and Economics and MTA-BME Condensed Matter Research Group, Budafoki ut 8, 1111, Budapest, Hungary
| | - Dimitry Akhmetzyanov
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue Str. 7, 60438, Frankfurt-am-Main, Germany
| | - Hakim Karoui
- Aix-Marseille Université, CNRS, ICR UMR 7273, 13397, Marseille cedex 20, France
| | - Didier Siri
- Aix-Marseille Université, CNRS, ICR UMR 7273, 13397, Marseille cedex 20, France
| | - Fabien Aussenac
- Bruker BioSpin S.A.S., 34 rue de l'industrie, 67166, Wissembourg, France
| | - Werner Maas
- Bruker BioSpin Corporation, 15 Fortune Drive, Billerica, Massachusetts, 01821, USA
| | - Ralph T Weber
- Bruker BioSpin Corporation, 15 Fortune Drive, Billerica, Massachusetts, 01821, USA
| | - Thomas Prisner
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue Str. 7, 60438, Frankfurt-am-Main, Germany
| | - Mélanie Rosay
- Bruker BioSpin Corporation, 15 Fortune Drive, Billerica, Massachusetts, 01821, USA
| | - Paul Tordo
- Aix-Marseille Université, CNRS, ICR UMR 7273, 13397, Marseille cedex 20, France.
| | - Olivier Ouari
- Aix-Marseille Université, CNRS, ICR UMR 7273, 13397, Marseille cedex 20, France.
| |
Collapse
|
21
|
Salnikov ES, Aisenbrey C, Aussenac F, Ouari O, Sarrouj H, Reiter C, Tordo P, Engelke F, Bechinger B. Membrane topologies of the PGLa antimicrobial peptide and a transmembrane anchor sequence by Dynamic Nuclear Polarization/solid-state NMR spectroscopy. Sci Rep 2016; 6:20895. [PMID: 26876950 PMCID: PMC4753517 DOI: 10.1038/srep20895] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/11/2016] [Indexed: 12/23/2022] Open
Abstract
Dynamic Nuclear Polarization (DNP) has been introduced to overcome the sensitivity limitations of nuclear magnetic resonance (NMR) spectroscopy also of supported lipid bilayers. When investigated by solid-state NMR techniques the approach typically involves doping the samples with biradicals and their investigation at cryo-temperatures. Here we investigated the effects of temperature and membrane hydration on the topology of amphipathic and hydrophobic membrane polypeptides. Although the antimicrobial PGLa peptide in dimyristoyl phospholipids is particularly sensitive to topological alterations, the DNP conditions represent well its membrane alignment also found in bacterial lipids at ambient temperature. With a novel membrane-anchored biradical and purpose-built hardware a 17-fold enhancement in NMR signal intensity is obtained by DNP which is one of the best obtained for a truly static matrix-free system. Furthermore, a membrane anchor sequence encompassing 19 hydrophobic amino acid residues was investigated. Although at cryotemperatures the transmembrane domain adjusts it membrane tilt angle by about 10 degrees, the temperature dependence of two-dimensional separated field spectra show that freezing the motions can have beneficial effects for the structural analysis of this sequence.
Collapse
Affiliation(s)
| | - Christopher Aisenbrey
- University of Strasbourg/CNRS, UMR7177, Chemistry Institute, 67070 Strasbourg, France
| | - Fabien Aussenac
- Bruker BioSpin, 34, rue de l’Industrie, 67166 Wissembourg, France
| | - Olivier Ouari
- Aix-Marseille University, Institut de Chimie Radicalaire, UMR 7273, Faculté des Sciences, 13397 Marseille, Cédex 20, France
| | - Hiba Sarrouj
- University of Strasbourg/CNRS, UMR7177, Chemistry Institute, 67070 Strasbourg, France
- Bruker BioSpin, Silberstreifen, 76287 Rheinstetten, Germany
| | | | - Paul Tordo
- Aix-Marseille University, Institut de Chimie Radicalaire, UMR 7273, Faculté des Sciences, 13397 Marseille, Cédex 20, France
| | - Frank Engelke
- Bruker BioSpin, Silberstreifen, 76287 Rheinstetten, Germany
| | - Burkhard Bechinger
- University of Strasbourg/CNRS, UMR7177, Chemistry Institute, 67070 Strasbourg, France
| |
Collapse
|
22
|
Tan X, Song Y, Liu H, Zhong Q, Rockenbauer A, Villamena FA, Zweier JL, Liu Y. Supramolecular host-guest interaction of trityl-nitroxide biradicals with cyclodextrins: modulation of spin-spin interaction and redox sensitivity. Org Biomol Chem 2016; 14:1694-701. [PMID: 26700002 DOI: 10.1039/c5ob02450a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Supramolecular host-guest interactions of trityl-nitroxide (TN) biradicals CT02-VT, CT02-AT and CT02-GT with methyl-β-cyclodextrin (M-β-CD), hydroxypropyl-β-cyclodextrin (H-β-CD) and γ-cyclodextrin (γ-CD) were investigated by EPR spectroscopy. In the presence of cyclodextrins (i.e., γ-CD, M-β-CD and H-β-CD), host-guest complexes of CT02-VT are formed where the nitroxide and linker parts possibly interact with the cyclodextrins' cavities. Complexation with cyclodextrins leads to suppression of the intramolecular through-space spin-spin exchange coupling in CT02-VT, thus allowing the determination of the through-bond spin-spin exchange coupling which was calculated to be 1.6 G using EPR simulations. Different types of cyclodextrins have different binding affinities with CT02-VT in the order of γ-CD (95 M(-1)) > M-β-CD (70 M(-1)) > H-β-CD (32 M(-1)). In addition, the effect of the linkers in TN biradicals on the host-guest interactions was also investigated. Among the three TN biradicals studied, CT02-VT has the highest association constant with one designated cyclodextrin derivative. On the other hand, the complexes of CT02-GT (∼ 22 G) and CT02-AT (7.7-9.0 G) with cyclodextrins have much higher through-bond spin-spin exchange couplings than those of CT02-VT (1.6 G) due to the shorter linkers than those of CT02-VT. Furthermore, the stability of TN biradicals towards ascorbate was significantly enhanced after the complexation with CDs, with an almost 2-fold attenuation of the second-order rate constants for all the biradicals. Therefore, the supramolecular host-guest interactions with cyclodextrins will be an alternative method to modulate the magnitude of the spin-spin interactions and redox sensitivity of TN biradicals, and the resulting complexes are promising as highly efficient DNP polarizing agents as well as EPR redox probes.
Collapse
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.
| | - 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.
| | - 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.
| | - Qinwen Zhong
- The First Affiliated Hospital, Gannan Medical University, Jiangxi 341000, 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, Budafoki ut 8, 1111 Budapest, Hungary
| | - Frederick A Villamena
- 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, USA. and Department of Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio 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, Ohio 43210, USA.
| | - 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. and 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, USA.
| |
Collapse
|
23
|
Geiger MA, Orwick-Rydmark M, Märker K, Franks WT, Akhmetzyanov D, Stöppler D, Zinke M, Specker E, Nazaré M, Diehl A, van Rossum BJ, Aussenac F, Prisner T, Akbey Ü, Oschkinat H. Temperature dependence of cross-effect dynamic nuclear polarization in rotating solids: advantages of elevated temperatures. Phys Chem Chem Phys 2016; 18:30696-30704. [DOI: 10.1039/c6cp06154k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
DNP on proteins at 200 K.
Collapse
|
24
|
Zhang Y, Baker PJ, Casabianca LB. BDPA-Doped Polystyrene Beads as Polarization Agents for DNP-NMR. J Phys Chem B 2015; 120:18-24. [PMID: 26717243 DOI: 10.1021/acs.jpcb.5b08741] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The aromatic free radical BDPA (α,γ-bisdiphenylene-β-phenylallyl), which has been widely used as a polarizing agent for Dynamic Nuclear Polarization (DNP) of hydrophobic analytes, has been incorporated into nanometer-scale polystyrene latex beads. We have shown that the resulting BDPA-doped beads can be used to hyperpolarize (13)C and (7)Li nuclei in aqueous environments, without the need for a glassing cosolvent. DNP enhancement factors of between 20 and 100 were achieved with overall BDPA concentrations of 2 mM or less. These Highly-Effective Polymer/Radical Beads (HYPR-beads) have potential use as an inexpensive polarizing agent for water-soluble analytes, and also have applications as model nanoparticles in DNP studies.
Collapse
Affiliation(s)
- Yunzhi Zhang
- Department of Chemistry, Clemson University , Clemson, South Carolina 29634, United States
| | - Phillip J Baker
- Department of Chemistry, Clemson University , Clemson, South Carolina 29634, United States
| | - Leah B Casabianca
- Department of Chemistry, Clemson University , Clemson, South Carolina 29634, United States
| |
Collapse
|
25
|
Salnikov ES, Sarrouj H, Reiter C, Aisenbrey C, Purea A, Aussenac F, Ouari O, Tordo P, Fedotenko I, Engelke F, Bechinger B. Solid-State NMR/Dynamic Nuclear Polarization of Polypeptides in Planar Supported Lipid Bilayers. J Phys Chem B 2015; 119:14574-83. [PMID: 26487390 DOI: 10.1021/acs.jpcb.5b07341] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Dynamic nuclear polarization has been developed to overcome the limitations of the inherently low signal intensity of NMR spectroscopy. This technique promises to be particularly useful for solid-state NMR spectroscopy where the signals are broadened over a larger frequency range and most investigations rely on recording low gamma nuclei. To extend the range of possible investigations, a triple-resonance flat-coil solid-state NMR probe is presented with microwave irradiation capacities allowing the investigation of static samples at temperatures of 100 K, including supported lipid bilayers. The probe performance allows for two-dimensional separated local field experiments with high-power Lee-Goldberg decoupling and cross-polarization under simultaneous irradiation from a gyrotron microwave generator. Efficient cooling of the sample turned out to be essential for best enhancements and line shape and necessitated the development of a dedicated cooling chamber. Furthermore, a new membrane-anchored biradical is presented, and the geometry of supported membranes was optimized not only for good membrane alignment, handling, stability, and filling factor of the coil but also for heat and microwave dissipation. Enhancement factors of 17-fold were obtained, and a two-dimensional PISEMA spectrum of a transmembrane helical peptide was obtained in less than 2 h.
Collapse
Affiliation(s)
- Evgeniy S Salnikov
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177 , 67070 Strasbourg, France
| | - Hiba Sarrouj
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177 , 67070 Strasbourg, France.,Bruker BioSpin, Silberstreifen, 76287 Rheinstetten, Germany
| | | | - Christopher Aisenbrey
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177 , 67070 Strasbourg, France
| | - Armin Purea
- Bruker BioSpin, Silberstreifen, 76287 Rheinstetten, Germany
| | - Fabien Aussenac
- Bruker BioSpin, 34, rue de l'Industrie, 67166 Wissembourg, France
| | - Olivier Ouari
- Aix Marseille Université, CNRS , Institut de Chimie Radicalaire, UMR 7273, 13013 Marseille, France
| | - Paul Tordo
- Aix Marseille Université, CNRS , Institut de Chimie Radicalaire, UMR 7273, 13013 Marseille, France
| | - Illya Fedotenko
- Aix Marseille Université, CNRS , Institut de Chimie Radicalaire, UMR 7273, 13013 Marseille, France
| | - Frank Engelke
- Bruker BioSpin, Silberstreifen, 76287 Rheinstetten, Germany
| | - Burkhard Bechinger
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177 , 67070 Strasbourg, France
| |
Collapse
|
26
|
Mathies G, Caporini MA, Michaelis VK, Liu Y, Hu KN, Mance D, Zweier JL, Rosay M, Baldus M, Griffin RG. Efficient Dynamic Nuclear Polarization at 800 MHz/527 GHz with Trityl-Nitroxide Biradicals. Angew Chem Int Ed Engl 2015; 54:11770-4. [PMID: 26268156 PMCID: PMC5407364 DOI: 10.1002/anie.201504292] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/16/2015] [Indexed: 11/08/2022]
Abstract
Cross-effect (CE) dynamic nuclear polarization (DNP) is a rapidly developing technique that enhances the signal intensities in magic-angle spinning (MAS) NMR spectra. We report CE DNP experiments at 211, 600, and 800 MHz using a new series of biradical polarizing agents referred to as TEMTriPols, in which a nitroxide (TEMPO) and a trityl radical are chemically tethered. The TEMTriPol molecule with the optimal performance yields a record (1) H NMR signal enhancement of 65 at 800 MHz at a concentration of 10 mM in a glycerol/water solvent matrix. The CE DNP enhancement for the TEMTriPol biradicals does not decrease as the magnetic field is increased in the manner usually observed for bis-nitroxides. Instead, the relatively strong exchange interaction between the trityl and nitroxide moieties determines the magnetic field at which the optimum enhancement is observed.
Collapse
Affiliation(s)
- Guinevere Mathies
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139 (USA).
| | - Marc A Caporini
- Bruker BioSpin Corporation, 15 Fortune Drive, Billerica, MA 01821 (USA)
- Current address: Amgen Inc., 360 Binney Street, Cambridge, MA 02142 (USA)
| | - Vladimir K Michaelis
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139 (USA)
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070 (China).
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210 (USA).
| | - Kan-Nian Hu
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139 (USA)
- Current address: Vertex Pharmaceuticals Incorporated, 50 Northern Avenue, Boston, MA 02210 (USA)
| | - Deni Mance
- NMR Spectroscopy, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht (The Netherlands)
| | - Jay L Zweier
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210 (USA)
| | - Melanie Rosay
- Bruker BioSpin Corporation, 15 Fortune Drive, Billerica, MA 01821 (USA)
| | - Marc Baldus
- NMR Spectroscopy, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht (The Netherlands)
| | - Robert G Griffin
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139 (USA).
| |
Collapse
|
27
|
Ravera E, Michaelis VK, Ong TC, Keeler EG, Martelli T, Fragai M, Griffin RG, Luchinat C. Biosilica-Entrapped Enzymes Studied by Using Dynamic Nuclear-Polarization-Enhanced High-Field NMR Spectroscopy. Chemphyschem 2015; 16:2751-2754. [PMID: 26266832 PMCID: PMC4752418 DOI: 10.1002/cphc.201500549] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Indexed: 11/08/2022]
Abstract
Enzymes are used as environmentally friendly catalysts in many industrial applications, and are frequently immobilized in a matrix to improve their chemical stability for long-term storage and reusability. Recently, it was shown that an atomic-level description of proteins immobilized in a biosilica matrix can be attained by examining their magic-angle spinning (MAS) NMR spectra. However, even though MAS NMR is an excellent tool for determining structure, it is severely hampered by sensitivity. In this work we provide the proof of principle that NMR characterization of biosilica-entrapped enzymes could be assisted by high-field dynamic nuclear polarization (DNP).
Collapse
Affiliation(s)
- Enrico Ravera
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino (FI), Italy
| | - Vladimir K. Michaelis
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ta-Chung Ong
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Eric G. Keeler
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Tommaso Martelli
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino (FI), Italy
| | - Marco Fragai
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino (FI), Italy
| | - Robert G. Griffin
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino (FI), Italy
| |
Collapse
|
28
|
Mathies G, Caporini MA, Michaelis VK, Liu Y, Hu KN, Mance D, Zweier JL, Rosay M, Baldus M, Griffin RG. Efficient Dynamic Nuclear Polarization at 800 MHz/527 GHz with Trityl-Nitroxide Biradicals. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504292] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
29
|
van der Cruijsen EAW, Koers EJ, Sauvée C, Hulse RE, Weingarth M, Ouari O, Perozo E, Tordo P, Baldus M. Biomolecular DNP-Supported NMR Spectroscopy using Site-Directed Spin Labeling. Chemistry 2015; 21:12971-7. [DOI: 10.1002/chem.201501376] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Indexed: 12/24/2022]
|
30
|
Cellular solid-state NMR investigation of a membrane protein using dynamic nuclear polarization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:342-9. [PMID: 25017802 DOI: 10.1016/j.bbamem.2014.07.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/30/2014] [Accepted: 07/02/2014] [Indexed: 12/16/2022]
Abstract
While an increasing number of structural biology studies successfully demonstrate the power of high-resolution structures and dynamics of membrane proteins in fully understanding their function, there is considerable interest in developing NMR approaches to obtain such information in a cellular setting. As long as the proteins inside the living cell tumble rapidly in the NMR timescale, recently developed in-cell solution NMR approaches can provide 3D structural information. However, there are numerous challenges to study membrane proteins inside a cell. Research in our laboratory is focused on developing a combination of solid-state NMR and biological approaches to overcome these challenges in order to obtain high-resolution structural insights into electron transfer processes mediated by membrane-bound proteins like mammalian cytochrome-b5, cytochrome-P450 and cytochrome-P450-reductase. In this study, we demonstrate the feasibility of using dynamic nuclear polarization (DNP) magic angle spinning (MAS) NMR spectroscopy for in-cell studies on a membrane-anchored protein. Our experimental results obtained from ¹³C-labeled membrane-anchored cytochrome-b5 in native Escherichia coli cells show a ~16-fold DNP signal enhancement. Further, results obtained from a 2D ¹³C/¹³C chemical shift correlation MAS experiment demonstrate the feasibility of suppressing the background signals from other cellular contents for high-resolution structural studies on membrane proteins. We believe that this study would pave new avenues for high-resolution structural studies on a variety of membrane-associated proteins and their complexes in the cellular context to fully understand their functional roles in physiological processes.
Collapse
|
31
|
Kiesewetter MK, Michaelis VK, Walish JJ, Griffin RG, Swager TM. High field dynamic nuclear polarization NMR with surfactant sheltered biradicals. J Phys Chem B 2014; 118:1825-30. [PMID: 24506193 PMCID: PMC3983347 DOI: 10.1021/jp410387e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 01/28/2014] [Indexed: 12/27/2022]
Abstract
We illustrate the ability to place a water-insoluble biradical, bTbk, into a glycerol/water matrix with the assistance of a surfactant, sodium octyl sulfate (SOS). This surfactant approach enables a previously water insoluble biradical, bTbk, with favorable electron-electron dipolar coupling to be used for dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) experiments in frozen, glassy, aqueous media. Nuclear Overhauser enhancement (NOE) and paramagnetic relaxation enhancement (PRE) experiments are conducted to determine the distribution of urea and several biradicals within the SOS macromolecular assembly. We also demonstrate that SOS assemblies are an effective approach by which mixed biradicals are created through an assembly process.
Collapse
Affiliation(s)
- Matthew K Kiesewetter
- Department of Chemistry and ‡Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | | | | | | | | |
Collapse
|
32
|
Lelli M, Rossini AJ, Casano G, Ouari O, Tordo P, Lesage A, Emsley L. Hydrophobic radicals embedded in neutral surfactants for dynamic nuclear polarization of aqueous environments at 9.4 Tesla. Chem Commun (Camb) 2014; 50:10198-201. [DOI: 10.1039/c4cc02152e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Large DNP enhancements of NMR signals are demonstrated from hydrophobic radicals solubilised in aqueous environments by biologically compatible neutral amphiphiles.
Collapse
Affiliation(s)
- Moreno Lelli
- Centre de RMN à Trés Hauts Champs
- Institut de Sciences Analytiques (CNRS/ENS Lyon/UCB Lyon 1)
- Université de Lyon
- 69100 Villeurbanne, France
| | - Aaron J. Rossini
- Centre de RMN à Trés Hauts Champs
- Institut de Sciences Analytiques (CNRS/ENS Lyon/UCB Lyon 1)
- Université de Lyon
- 69100 Villeurbanne, France
| | - Gilles Casano
- Aix-Marseille Université
- CNRS, ICR UMR 7273
- 13397 Marseille, France
| | - Olivier Ouari
- Aix-Marseille Université
- CNRS, ICR UMR 7273
- 13397 Marseille, France
| | - Paul Tordo
- Aix-Marseille Université
- CNRS, ICR UMR 7273
- 13397 Marseille, France
| | - Anne Lesage
- Centre de RMN à Trés Hauts Champs
- Institut de Sciences Analytiques (CNRS/ENS Lyon/UCB Lyon 1)
- Université de Lyon
- 69100 Villeurbanne, France
| | - Lyndon Emsley
- Centre de RMN à Trés Hauts Champs
- Institut de Sciences Analytiques (CNRS/ENS Lyon/UCB Lyon 1)
- Université de Lyon
- 69100 Villeurbanne, France
| |
Collapse
|