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Movellan K, Wegstroth M, Overkamp K, Leonov A, Becker S, Andreas LB. Imidazole-Imidazole Hydrogen Bonding in the pH-Sensing Histidine Side Chains of Influenza A M2. J Am Chem Soc 2020; 142:2704-2708. [PMID: 31970979 PMCID: PMC7307898 DOI: 10.1021/jacs.9b10984] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Indexed: 12/28/2022]
Abstract
The arrangement of histidine side chains in influenza A M2 tetramer determines their pKa values, which define pH-controlled proton conduction critical to the virus lifecycle. Both water-associated and hydrogen-bonded imidazole-imidazolium histidine quaternary structures have been proposed, based on crystal structures and NMR chemical shifts, respectively. Here we show, using the conduction domain construct of M2 in lipid bilayers, that the imidazole rings are hydrogen bonded even at a pH of 7.8 in the neutral charge state. An intermolecular 8.9 ± 0.3 Hz 2hJNN hydrogen bond is observed between H37 Nε and Nδ recorded in a fully protonated sample with 100 kHz magic-angle spinning. This interaction could not be detected in the drug-bound sample.
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Affiliation(s)
- Kumar
Tekwani Movellan
- Department of NMR Based Structural
Biology, Max Planck Institute for Biophysical
Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Melanie Wegstroth
- Department of NMR Based Structural
Biology, Max Planck Institute for Biophysical
Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Kerstin Overkamp
- Department of NMR Based Structural
Biology, Max Planck Institute for Biophysical
Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Andrei Leonov
- Department of NMR Based Structural
Biology, Max Planck Institute for Biophysical
Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Stefan Becker
- Department of NMR Based Structural
Biology, Max Planck Institute for Biophysical
Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Loren B. Andreas
- Department of NMR Based Structural
Biology, Max Planck Institute for Biophysical
Chemistry, Am Fassberg 11, Göttingen 37077, Germany
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2
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Webber AL, Yates JR, Zilka M, Sturniolo S, Uldry AC, Corlett EK, Pickard CJ, Pérez-Torralba M, Angeles Garcia M, Santa Maria D, Claramunt RM, Brown SP. Weak Intermolecular CH···N Hydrogen Bonding: Determination of 13CH- 15N Hydrogen-Bond Mediated J Couplings by Solid-State NMR Spectroscopy and First-Principles Calculations. J Phys Chem A 2020; 124:560-572. [PMID: 31880451 DOI: 10.1021/acs.jpca.9b10726] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Weak hydrogen bonds are increasingly hypothesized to play key roles in a wide range of chemistry from catalysis to gelation to polymer structure. Here, 15N/13C spin-echo magic-angle spinning (MAS) solid-state nuclear magnetic resonance (NMR) experiments are applied to "view" intermolecular CH···N hydrogen bonding in two selectively labeled organic compounds, 4-[15N] cyano-4'-[13C2] ethynylbiphenyl (1) and [15N3,13C6]-2,4,6-triethynyl-1,3,5-triazine (2). The synthesis of 2-15N3,13C6 is reported here for the first time via a multistep procedure, where the key element is the reaction of [15N3]-2,4,6-trichloro-1,3,5-triazine (5) with [13C2]-[(trimethylsilyl)ethynyl]zinc chloride (8) to afford its immediate precursor [15N3,13C6]-2,4,6-tris[(trimethylsilyl)ethynyl]-1,3,5-triazine (9). Experimentally determined hydrogen-bond-mediated 2hJCN couplings (4.7 ± 0.4 Hz (1) and 4.1 ± 0.3 Hz (2)) are compared with density functional theory (DFT) gauge-including projector augmented wave (GIPAW) calculations, whereby species-independent coupling values 2hKCN (29.0 × 1019 kg m-2 s-2 A-2 (1) and 27.9 × 1019 kg m-2 s-2 A-2 (2)) quantitatively demonstrate the J couplings for these "weak" CH···N hydrogen bonds to be of a similar magnitude to those for conventionally observed NH···O hydrogen-bonding interactions in uracil (2hKNO: 28.1 and 36.8 × 1019 kg m-2 s-2 A-2). Moreover, the GIPAW calculations show a clear correlation between increasing 2hJCN (and 3hJCN) coupling and reducing C(H)···N and H···N hydrogen-bonding distances, with the Fermi contact term accounting for at least 98% of the isotropic 2hJCN coupling.
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Affiliation(s)
- Amy L Webber
- Department of Physics , University of Warwick , Coventry CV4 7AL , U.K
| | - Jonathan R Yates
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , U.K
| | - Miri Zilka
- Department of Physics , University of Warwick , Coventry CV4 7AL , U.K
| | - Simone Sturniolo
- Scientific Computing Department , Rutherford Appleton Laboratory , Chilton, Didcot , Oxfordshire OX11 0QX , U.K
| | - Anne-Christine Uldry
- Department for Biomedical Research , University of Bern , Freiburgstrasse 15 , Bern 3010 , Switzerland
| | - Emily K Corlett
- Department of Physics , University of Warwick , Coventry CV4 7AL , U.K
| | - Chris J Pickard
- Department of Materials Science and Metallurgy , University of Cambridge , 27 Charles Babbage Road , Cambridge CB3 0FS , U.K.,Advanced Institute for Materials Research , Tohoku University 2-1-1 Katahira , Aoba, Sendai 980-8577 , Japan
| | - Marta Pérez-Torralba
- Departamento de Química Orgánica y Bio-Orgánica , Facultad de Ciencias, UNED , Senda del Rey 9 , Madrid E-28040 , Spain
| | - M Angeles Garcia
- Departamento de Química Orgánica y Bio-Orgánica , Facultad de Ciencias, UNED , Senda del Rey 9 , Madrid E-28040 , Spain
| | - Dolores Santa Maria
- Departamento de Química Orgánica y Bio-Orgánica , Facultad de Ciencias, UNED , Senda del Rey 9 , Madrid E-28040 , Spain
| | - Rosa M Claramunt
- Departamento de Química Orgánica y Bio-Orgánica , Facultad de Ciencias, UNED , Senda del Rey 9 , Madrid E-28040 , Spain
| | - Steven P Brown
- Department of Physics , University of Warwick , Coventry CV4 7AL , U.K
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3
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Zhang W, Yoon MK, Meredith RJ, Zajicek J, Oliver AG, Hadad M, Frey MH, Carmichael I, Serianni AS. 13C- 13C spin-coupling constants in crystalline 13C-labeled saccharides: conformational effects interrogated by solid-state 13C NMR spectroscopy. Phys Chem Chem Phys 2019; 21:23576-23588. [PMID: 31621725 DOI: 10.1039/c9cp03228b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solid-state 13C NMR spectroscopy has been used in conjunction with selectively 13C-labeled mono- and disaccharides to measure 13C-13C spin-couplings (JCC) in crystalline samples. This experimental approach allows direct correlation of JCC values with specific molecular conformations since, in crystalline samples, molecular conformation is essentially static and can be determined by X-ray crystallography. JCC values measured in the solid-state in known molecular conformations can then be compared to corresponding JCC values calculated in the same conformations using density functional theory (DFT). The latter comparisons provide important validation of DFT-calculated J-couplings, which is not easily obtained by other approaches and is fundamental to obtaining reliable experiment-based conformational models from redundant J-couplings by MA'AT analysis. In this study, representative 1JCC, 2JCCC and 3JCOCC values were studied as either intra-residue couplings in the aldohexopyranosyl rings of monosaccharides or inter-residue (trans-glycoside) couplings in disaccharides. The results demonstrate that (a) accurate JCC values can be measured in crystalline saccharides that have been suitably labeled with 13C, and (b) DFT-calculated JCC values compare favorably with those determined by solid-state 13C NMR when molecular conformation is a constant in both determinations.
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Affiliation(s)
- Wenhui Zhang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556-5670, USA.
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4
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Advanced solid-state NMR methods for characterising structure and self-assembly in supramolecular chemistry, polymers and hydrogels. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.02.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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5
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Hughes CE, Reddy GNM, Masiero S, Brown SP, Williams PA, Harris KDM. Determination of a complex crystal structure in the absence of single crystals: analysis of powder X-ray diffraction data, guided by solid-state NMR and periodic DFT calculations, reveals a new 2'-deoxyguanosine structural motif. Chem Sci 2017; 8:3971-3979. [PMID: 28553539 PMCID: PMC5433513 DOI: 10.1039/c7sc00587c] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 03/15/2017] [Indexed: 12/20/2022] Open
Abstract
Derivatives of guanine exhibit diverse supramolecular chemistry, with a variety of distinct hydrogen-bonding motifs reported in the solid state, including ribbons and quartets, which resemble the G-quadruplex found in nucleic acids with sequences rich in guanine. Reflecting this diversity, the solid-state structural properties of 3',5'-bis-O-decanoyl-2'-deoxyguanosine, reported in this paper, reveal a hydrogen-bonded guanine ribbon motif that has not been observed previously for 2'-deoxyguanosine derivatives. In this case, structure determination was carried out directly from powder XRD data, representing one of the most challenging organic molecular structures (a 90-atom molecule) that has been solved to date by this technique. While specific challenges were encountered in the structure determination process, a successful outcome was achieved by augmenting the powder XRD analysis with information derived from solid-state NMR data and with dispersion-corrected periodic DFT calculations for structure optimization. The synergy of experimental and computational methodologies demonstrated in the present work is likely to be an essential feature of strategies to further expand the application of powder XRD as a technique for structure determination of organic molecular materials of even greater complexity in the future.
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Affiliation(s)
- Colan E Hughes
- School of Chemistry , Cardiff University , Park Place , Cardiff , CF10 3AT , UK .
| | | | - Stefano Masiero
- Dipartimento di Chimica "G. Ciamician" , Alma Mater Studiorum - Università di Bologna , via San Giacomo , 11-40126 Bologna , Italy
| | - Steven P Brown
- Department of Physics , University of Warwick , Coventry , CV4 7AL , UK
| | - P Andrew Williams
- School of Chemistry , Cardiff University , Park Place , Cardiff , CF10 3AT , UK .
| | - Kenneth D M Harris
- School of Chemistry , Cardiff University , Park Place , Cardiff , CF10 3AT , UK .
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6
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Moran RF, Dawson DM, Ashbrook SE. Exploiting NMR spectroscopy for the study of disorder in solids. INT REV PHYS CHEM 2017. [DOI: 10.1080/0144235x.2017.1256604] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Robert F. Moran
- School of Chemistry, EaStCHEM and St Andrews Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
| | - Daniel M. Dawson
- School of Chemistry, EaStCHEM and St Andrews Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
| | - Sharon E. Ashbrook
- School of Chemistry, EaStCHEM and St Andrews Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
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7
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Čoga L, Spindler L, Masiero S, Drevenšek-Olenik I. Molecular recognition of a lipophilic guanosine derivative in Langmuir films at the air-water interface. Biochim Biophys Acta Gen Subj 2016; 1861:1463-1470. [PMID: 27913187 DOI: 10.1016/j.bbagen.2016.11.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/25/2016] [Accepted: 11/26/2016] [Indexed: 11/26/2022]
Abstract
Molecular recognition of a lipophilic deoxyguanosine derivative at the air-water interface was investigated by film balance experiments and Brewster Angle Microscopy. Results showed that guanosine, despite strong tendency towards self-assembly, interacts with both complementary and noncomplementary liponucleosides (lipophilic derivatives of deoxycytidine and deoxythymidine). At surface pressures below 17mN/m, attractive and repulsive interactions were present in case of both mixed monolayers and were the strongest at guanosine molar fractions of 0.5 and 0.75. At higher values of surface pressure, deoxyguanosine-deoxycytidine interactions were strictly attractive and were present only for monolayers with guanosine molar fraction of 0.75. On the contrary, attractive and repulsive interactions remained present in case of deoxyguanosine-deoxythymidine mixed monolayers. This indicates that interactions between guanosine and cytidine are much stronger than guanosine-thymidine interactions. Interactions for none of the nucleoside pairs, however, are specific and π-stacking interactions between the aromatic planes of liponucleoside derivatives probably dominate over hydrogen bonding interactions. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.
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Affiliation(s)
- Lucija Čoga
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
| | - Lea Spindler
- Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia; Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
| | - Stefano Masiero
- Alma Mater Studiorum - Università di Bologna, Dipartimento "Giacomo Ciamician", Via San Giacomo 11, I-40126 Bologna, Italy
| | - Irena Drevenšek-Olenik
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia; Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
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8
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Fenniri H, Tikhomirov GA, Brouwer DH, Bouatra S, El Bakkari M, Yan Z, Cho JY, Yamazaki T. High Field Solid-State NMR Spectroscopy Investigation of 15N-Labeled Rosette Nanotubes: Hydrogen Bond Network and Channel-Bound Water. J Am Chem Soc 2016; 138:6115-8. [DOI: 10.1021/jacs.6b02420] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Hicham Fenniri
- 313 Snell
Engineering Center, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | | | - Darren H. Brouwer
- Department of Chemistry, Redeemer University College, 777 Garner Road East, Ancaster, Ontario L9K 1J4, Canada
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9
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Vioglio PC, Chierotti MR, Gobetto R. Solid-state nuclear magnetic resonance as a tool for investigating the halogen bond. CrystEngComm 2016. [DOI: 10.1039/c6ce02219g] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Märker K, Pingret M, Mouesca JM, Gasparutto D, Hediger S, De Paëpe G. A New Tool for NMR Crystallography: Complete 13C/15N Assignment of Organic Molecules at Natural Isotopic Abundance Using DNP-Enhanced Solid-State NMR. J Am Chem Soc 2015; 137:13796-9. [DOI: 10.1021/jacs.5b09964] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Katharina Märker
- Univ. Grenoble Alpes, INAC, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - Morgane Pingret
- Univ. Grenoble Alpes, INAC, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - Jean-Marie Mouesca
- Univ. Grenoble Alpes, INAC, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - Didier Gasparutto
- Univ. Grenoble Alpes, INAC, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
| | - Sabine Hediger
- Univ. Grenoble Alpes, INAC, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
- CNRS, SCIB, F-38000 Grenoble, France
| | - Gaël De Paëpe
- Univ. Grenoble Alpes, INAC, F-38000 Grenoble, France
- CEA, INAC, F-38000 Grenoble, France
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11
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Sanz Camacho P, Athukorala Arachchige KS, Slawin AMZ, Green TFG, Yates JR, Dawson DM, Woollins JD, Ashbrook SE. Unusual Intermolecular “Through-Space” J Couplings in P–Se Heterocycles. J Am Chem Soc 2015; 137:6172-5. [DOI: 10.1021/jacs.5b03353] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Paula Sanz Camacho
- School
of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St. Andrews, Fife, KY16 9ST, U.K
| | | | - Alexandra M. Z. Slawin
- School
of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St. Andrews, Fife, KY16 9ST, U.K
| | | | | | - Daniel M. Dawson
- School
of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St. Andrews, Fife, KY16 9ST, U.K
| | - J. Derek Woollins
- School
of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St. Andrews, Fife, KY16 9ST, U.K
| | - Sharon E. Ashbrook
- School
of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St. Andrews, Fife, KY16 9ST, U.K
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12
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Reddy GNM, Cook DS, Iuga D, Walton RI, Marsh A, Brown SP. An NMR crystallography study of the hemihydrate of 2', 3'-O-isopropylidineguanosine. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 65:41-48. [PMID: 25686689 DOI: 10.1016/j.ssnmr.2015.01.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 01/05/2015] [Accepted: 01/08/2015] [Indexed: 06/04/2023]
Abstract
An NMR crystallography study of the hemihydrate of 2', 3'-O-isopropylidineguanosine (Gace) is presented, together with powder X-ray diffraction and thermogravimetric analysis. (1)H double-quantum and (14)N-(1)H HMQC spectra recorded at 850MHz and 75kHz MAS (using a JEOL 1mm probe) are presented together with a (1)H-(13)C refocused INEPT spectrum recorded at 500MHz and 12.5kHz MAS using eDUMBO-122(1)H homonuclear decoupling. NMR chemical shieldings are calculated using the GIPAW (gauge-including projector augmented wave) method; good two-dimensional agreement between calculation and experiment is observed for (13)C and (1)H chemical shifts for directly bonded CH and CH3 peaks. There are two Gace molecules in the asymmetric unit cell: differences in specific (1)H chemical shifts are rationalised in terms of the strength of CH-π and intermolecular hydrogen bonding interactions.
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Affiliation(s)
| | - Daniel S Cook
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Dinu Iuga
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK
| | - Richard I Walton
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Andrew Marsh
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Steven P Brown
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
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13
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Bou Zerdan R, Cohn P, Puodziukynaite E, Baker MB, Voisin M, Sarun C, Castellano RK. Synthesis, optical properties, and electronic structures of nucleobase-containing π-conjugated oligomers. J Org Chem 2015; 80:1828-40. [PMID: 25581330 DOI: 10.1021/jo502773g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The molecular recognition properties of the nucleobases instruct the formation of complex three-dimensional architectures in natural and synthetic systems; relatively unexplored is their use as building blocks for π-conjugated materials where they might mutually tune electronic and supramolecular structures. Toward this goal, an introductory set (1a-d and 2a-d) of six purine-terminated and two pyrimidine-terminated π-conjugated oligomers has been synthesized and used to develop experimental electronic and photophysical structure-property trends. Unlike 2,2':5',2″-terthiophene (TTT) derivatives 2a-d, intramolecular charge transfer dominates oligomers 1a-d bearing a 4,7-bisthienylbenzothiadiazole (TBT) spacer due to the strong electron-accepting ability of its benzothiadiazole (BTD) ring. The resulting donor-acceptor-donor systems feature lower HOMO-LUMO gaps than the terthiophene-linked nucleobases (ΔE(g) ∼ 1.8 eV vs 2.4 eV based on electrochemical measurements), and the lowest so far for π-conjugated molecules that include nucleobases within the π-framework. Experiments reveal a dependence of photophysical and electronic structure on the nature of the nucleobase and are in good agreement with theoretical calculations performed at the B3LYP/6-31+G** level. Overall, the results show how nucleobase heterocycles can be installed within π-systems to tune optical and electronic properties. Future work will evaluate the consequences of these information-rich components on supramolecular π-conjugated structure.
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Affiliation(s)
- Raghida Bou Zerdan
- Department of Chemistry, University of Florida , P.O. Box 117200, Gainesville, Florida 32611, United States
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14
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Abstract
Recent applications of solid-state NMR spectroscopy to studies of nucleic acids and their components.
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Affiliation(s)
- Martin Dračínský
- Institute of Organic Chemistry and Biochemistry
- Prague
- Czech Republic
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15
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Wang L, Kong H, Zhang C, Sun Q, Cai L, Tan Q, Besenbacher F, Xu W. Formation of a G-quartet-Fe complex and modulation of electronic and magnetic properties of the Fe center. ACS NANO 2014; 8:11799-11805. [PMID: 25347538 DOI: 10.1021/nn5054156] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although the G-quartet structure has been extensively investigated due to its biological importance, the formation mechanism, in particular, the necessity of metal centers, of an isolated G-quartet on solid surfaces remains ambiguous. Here, by using scanning tunneling microscopy under well-controlled ultra-high-vacuum conditions and density functional theory calculations we have been able to clarify that besides the intraquartet hydrogen bonding a metal center is mandatory for the formation of an isolated G-quartet. Furthermore, by subtly perturbing the local coordination bonding schemes within the formed G-quartet complex via local nanoscale scanning tunneling microscopy manipulations, we succeed in modulating the d orbitals and the accompanying magnetic properties of the metal center. Our results demonstrate the feasibility of forming an isolated G-quartet complex on a solid surface and that the strategy of modulating electronic and magnetic properties of the metal center can be extended to other related systems such as molecular spintronics.
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Affiliation(s)
- Likun Wang
- Tongji-Aarhus Joint Research Center for Nanostructures and Functional Nanomaterials and College of Materials Science and Engineering, Tongji University , Caoan Road 4800, Shanghai 201804, People's Republic of China
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16
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Lamellar versus compact self-assembly of lipoguanosine derivatives in thin surface films. Colloids Surf B Biointerfaces 2014; 121:114-21. [DOI: 10.1016/j.colsurfb.2014.05.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 04/17/2014] [Accepted: 05/17/2014] [Indexed: 11/20/2022]
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17
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Čoga L, Ilc T, Devetak M, Masiero S, Gramigna L, Spada GP, Drevenšek-Olenik I. Liponucleoside thin films: The special behaviour of guanosine. Colloids Surf B Biointerfaces 2013. [DOI: 10.1016/j.colsurfb.2012.10.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Gonnelli A, Ortore MG, Baldassarri EJ, Spada GP, Pieraccini S, Perone RC, Funari SS, Mariani P. Small-angle X-ray scattering study of self-assembling lipophilic guanines in organic solvents: G-quadruplex formation and cation effects in cyclohexane. J Phys Chem B 2013; 117:1095-103. [PMID: 23294474 DOI: 10.1021/jp3121929] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Lipophilic guanilic derivatives (lipoGs) dissolved in organic solvents can undergo different self-assembly pathways based on different H-bonded motifs, e.g., the cyclic discrete G-quartet, which forms in the presence of alkali-metal ions, and the "infinite" tape-like G-ribbon observed in the absence of ions. Using in-solution small-angle X-ray scattering, we analyzed a series of lipoGs dissolved in cyclohexane in the presence of different salts. The formation of G-quartet based supramolecular aggregates has been confirmed, evidencing the coexistence equilibrium of octamers and noncovalent molecular nanowires (the so-called G-quadruplexes). By global fitting the scattering data, the concentration of the two kinds of particles as well as the nanowire length have been derived as a function of temperature for the different compounds and salts. The thermodynamic parameters show that the self-assembly aggregation process is enthalpy driven, while the observed enthalpy-entropy compensation suggests that similar stacking interactions control the self-assembly of the different compounds. However, the strength of the stacking interactions, and then the nanowire stability, depends on the nature of templating cations and on their capacity to fill the central cavity of quadruplexes, with the order Sr(+) < Na(+) ≲ K(+).
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Affiliation(s)
- A Gonnelli
- Dipartimento di Scienze della Vita e dell'Ambiente, Biophysics Research Group, Università Politecnica delle Marche, via Brecce Bianche, I-60131 Ancona, Italy
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Inui Y, Shiro M, Fukuzumi S, Kojima T. Quartet formation of a guanine derivative with an isopropyl group: crystal structures of “naked” G-quartets and thermodynamics of G-quartet formation. Org Biomol Chem 2013; 11:758-64. [DOI: 10.1039/c2ob26877a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Brown SP. Applications of high-resolution 1H solid-state NMR. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2012; 41:1-27. [PMID: 22177472 DOI: 10.1016/j.ssnmr.2011.11.006] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 11/15/2011] [Accepted: 11/16/2011] [Indexed: 05/25/2023]
Abstract
This article reviews the large increase in applications of high-resolution (1)H magic-angle spinning (MAS) solid-state NMR, in particular two-dimensional heteronuclear and homonuclear (double-quantum and spin-diffusion NOESY-like exchange) experiments, in the last five years. These applications benefit from faster MAS frequencies (up to 80 kHz), higher magnetic fields (up to 1 GHz) and pulse sequence developments (e.g., homonuclear decoupling sequences applicable under moderate and fast MAS). (1)H solid-state NMR techniques are shown to provide unique structural insight for a diverse range of systems including pharmaceuticals, self-assembled supramolecular structures and silica-based inorganic-organic materials, such as microporous and mesoporous materials and heterogeneous organometallic catalysts, for which single-crystal diffraction structures cannot be obtained. The power of NMR crystallography approaches that combine experiment with first-principles calculations of NMR parameters (notably using the GIPAW approach) are demonstrated, e.g., to yield quantitative insight into hydrogen-bonding and aromatic CH-π interactions, as well as to generate trial three-dimensional packing arrangements. It is shown how temperature-dependent changes in the (1)H chemical shift, linewidth and DQ-filtered signal intensity can be analysed to determine the thermodynamics and kinetics of molecular level processes, such as the making and breaking of hydrogen bonds, with particular application to proton-conducting materials. Other applications to polymers and biopolymers, inorganic compounds and bioinorganic systems, paramagnetic compounds and proteins are presented. The potential of new technological advances such as DNP methods and new microcoil designs is described.
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Affiliation(s)
- Steven P Brown
- Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
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21
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Webber AL, Masiero S, Pieraccini S, Burley JC, Tatton AS, Iuga D, Pham TN, Spada GP, Brown SP. Identifying guanosine self assembly at natural isotopic abundance by high-resolution 1H and 13C solid-state NMR spectroscopy. J Am Chem Soc 2011; 133:19777-95. [PMID: 22034827 DOI: 10.1021/ja206516u] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By means of the (1)H chemical shifts and the proton-proton proximities as identified in (1)H double-quantum (DQ) combined rotation and multiple-pulse spectroscopy (CRAMPS) solid-state NMR correlation spectra, ribbon-like and quartet-like self-assembly can be identified for guanosine derivatives without isotopic labeling for which it was not possible to obtain single crystals suitable for diffraction. Specifically, characteristic spectral fingerprints are observed for dG(C10)(2) and dG(C3)(2) derivatives, for which quartet-like and ribbon-like self-assembly has been unambiguously identified by (15)N refocused INADEQUATE spectra in a previous study of (15)N-labeled derivatives (Pham, T. N.; et al. J. Am. Chem. Soc.2005, 127, 16018). The NH (1)H chemical shift is observed to be higher (13-15 ppm) for ribbon-like self-assembly as compared to 10-11 ppm for a quartet-like arrangement, corresponding to a change from NH···N to NH···O intermolecular hydrogen bonding. The order of the two NH(2)(1)H chemical shifts is also inverted, with the NH(2) proton closest in space to the NH proton having a higher or lower (1)H chemical shift than that of the other NH(2) proton for ribbon-like as opposed to quartet-like self-assembly. For the dG(C3)(2) derivative for which a single-crystal diffraction structure is available, the distinct resonances and DQ peaks are assigned by means of gauge-including projector-augmented wave (GIPAW) chemical shift calculations. In addition, (14)N-(1)H correlation spectra obtained at 850 MHz under fast (60 kHz) magic-angle spinning (MAS) confirm the assignment of the NH and NH(2) chemical shifts for the dG(C3)(2) derivative and allow longer range through-space N···H proximities to be identified, notably to the N7 nitrogens on the opposite hydrogen-bonding face.
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Affiliation(s)
- Amy L Webber
- Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
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22
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Barrow NS, Yates JR, Feller SA, Holland D, Ashbrook SE, Hodgkinson P, Brown SP. Towards homonuclear J solid-state NMR correlation experiments for half-integer quadrupolar nuclei: experimental and simulated 11B MAS spin-echo dephasing and calculated 2JBB coupling constants for lithium diborate. Phys Chem Chem Phys 2011; 13:5778-89. [DOI: 10.1039/c0cp02343d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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23
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Yates JR. Prediction of NMR J-coupling in solids with the planewave pseudopotential approach. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2010; 48 Suppl 1:S23-S31. [PMID: 20625980 DOI: 10.1002/mrc.2646] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We review the calculation of NMR J-coupling in solid materials using the planewave pseudopotential formalism of Density Functional Theory. The methodology is briefly summarised and an account of recent applications is given. We discuss various aspects of the calculations which should be taken into account when comparing results with solid-state NMR experiments including anisotropy and orientation of the J tensors, the reduced coupling constant, and the relation between J and crystal structure.
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Affiliation(s)
- Jonathan R Yates
- Department of Materials, University of Oxford, Oxford OX1 3PH, UK.
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24
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Claramunt RM, Pérez-Torralba M, María DS, Sanz D, Elena B, Alkorta I, Elguero J. 15N-15N spin-spin coupling constants through intermolecular hydrogen bonds in the solid state. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 206:274-279. [PMID: 20716491 DOI: 10.1016/j.jmr.2010.07.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/13/2010] [Accepted: 07/25/2010] [Indexed: 05/29/2023]
Abstract
A 2hJNN intermolecular spin-spin coupling constant (SSCC) of 10.2±0.4 Hz has been measured for the powdered tetrachlorogallate salt of pyridinium solvated by pyridine (pyridine-H+⋯pyridine cation 3). Density Functional Theory (DFT) calculations at the B3LYP/6-311++G(d,p) level reproduced this value and two others reported in the literature for 2hJ intermolecular SSCCs, which were measured for complexes in solution.
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Affiliation(s)
- Rosa M Claramunt
- Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, UNED, Senda del Rey 9, E-28040 Madrid, Spain.
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25
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Schanda P, Huber M, Verel R, Ernst M, Meier BH. Direct detection of (3h)J(NC') hydrogen-bond scalar couplings in proteins by solid-state NMR spectroscopy. Angew Chem Int Ed Engl 2010; 48:9322-5. [PMID: 19894242 DOI: 10.1002/anie.200904411] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Paul Schanda
- Physical Chemistry, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland.
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26
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Schanda P, Huber M, Verel R, Ernst M, Meier B. Direct Detection of3hJNCâ²Hydrogen-Bond Scalar Couplings in Proteins by Solid-State NMR Spectroscopy. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200904411] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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27
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Brown SP. Recent Advances in Solid-State MAS NMR Methodology for Probing Structure and Dynamics in Polymeric and Supramolecular Systems. Macromol Rapid Commun 2009; 30:688-716. [DOI: 10.1002/marc.200800816] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Accepted: 02/06/2009] [Indexed: 01/12/2023]
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28
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Joyce SA, Yates JR, Pickard CJ, Brown SP. Density Functional Theory Calculations of Hydrogen-Bond-Mediated NMR J Coupling in the Solid State. J Am Chem Soc 2008; 130:12663-70. [DOI: 10.1021/ja800419m] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Siân A. Joyce
- Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., and Department of Physics, University of Warwick, Coventry CV4 7AL, U.K
| | - Jonathan R. Yates
- Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., and Department of Physics, University of Warwick, Coventry CV4 7AL, U.K
| | - Chris J. Pickard
- Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., and Department of Physics, University of Warwick, Coventry CV4 7AL, U.K
| | - Steven P. Brown
- Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., and Department of Physics, University of Warwick, Coventry CV4 7AL, U.K
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29
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O’Dell LA, Guerry P, Wong A, Abou Neel EA, Pham TN, Knowles JC, Brown SP, Smith ME. Quantification of crystalline phases and measurement of phosphate chain lengths in a mixed phase sample by 31P refocused INADEQUATE MAS NMR. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.02.070] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Griffin JM, Tripon C, Samoson A, Filip C, Brown SP. Low-load rotor-synchronised Hahn-echo pulse train (RS-HEPT) 1H decoupling in solid-state NMR: factors affecting MAS spin-echo dephasing times. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2007; 45 Suppl 1:S198-S208. [PMID: 18098353 DOI: 10.1002/mrc.2145] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Transverse dephasing times T(2)' in spin-echo MAS NMR using rotor-synchronised Hahn-echo pulse-train (RS-HEPT) low-load (1)H decoupling are evaluated. Experiments were performed at 300 and 600 MHz for (13)CH-labelled L-alanine and (15)NH(delta)-labelled L-histidine.HCl.H(2)O, together with SPINEVOLUTION simulations for a ten-spin system representing the crystal structure environment of the (13)CH carbon in L-alanine. For 30 kHz MAS and nu(1)((1)H) = 100 kHz at 300 MHz, a RS-HEPT T(2)' value of 17 +/- 1 ms was obtained for (13)CH-labelled L-alanine which is approximately 50% of the XiX T(2)' value of 33 +/- 2 ms. Optimum RS-HEPT decoupling performance is observed for a relative phase of alternate RS-HEPT pi-pulses, Deltaphi = phi'- phi, between 40 and 60 degrees . For experiments at 600 MHz and 30 kHz MAS with (13)CH-labelled L-alanine, the best RS-HEPT (nu(1)((1)H) = 100 kHz) T(2)' value was 3 times longer than that observed for low-power continuously applied sequences with nu(1)((1)H) < or =40 kHz, i.e. corresponding to the same average power dissipated in the probe. A marked improvement in RS-HEPT (1)H decoupling is observed for increasing MAS frequency: at 55.6 kHz MAS, a best RS-HEPT T(2)' value of 34 +/- 5 ms was recorded for (13)CH-labelled L-alanine. Much improved RS-HEPT broadband performance was also observed at 55.6 kHz MAS as compared to 30 kHz MAS.
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Affiliation(s)
- John M Griffin
- Department of Physics, University of Warwick, Coventry, UK
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31
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Cadars S, Sein J, Duma L, Lesage A, Pham TN, Baltisberger JH, Brown SP, Emsley L. The refocused INADEQUATE MAS NMR experiment in multiple spin-systems: interpreting observed correlation peaks and optimising lineshapes. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2007; 188:24-34. [PMID: 17588789 DOI: 10.1016/j.jmr.2007.05.016] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 05/18/2007] [Indexed: 05/12/2023]
Abstract
The robustness of the refocused INADEQUATE MAS NMR pulse sequence for probing through-bond connectivities has been demonstrated in a large range of solid-state applications. This pulse sequence nevertheless suffers from artifacts when applied to multispin systems, e.g. uniformly labeled (13)C solids, which distort the lineshapes and can potentially result in misleading correlation peaks. In this paper, we present a detailed account that combines product-operator analysis, numerical simulations and experiments of the behavior of a three-spin system during the refocused INADEQUATE pulse sequence. The origin of undesired anti-phase contributions to the spectral lineshapes are described, and we show that they do not interfere with the observation of long-range correlations (e.g. two-bond (13)C-(13)C correlations). The suppression of undesired contributions to the refocused INADEQUATE spectra is shown to require the removal of zero-quantum coherences within a z-filter. A method is proposed to eliminate zero-quantum coherences through dephasing by heteronuclear dipolar couplings, which leads to pure in-phase spectra.
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Affiliation(s)
- Sylvian Cadars
- Laboratoire de Chimie (UMR 5182 CNRS/ENS Lyon), Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France
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32
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Lena S, Cremonini MA, Federiconi F, Gottarelli G, Graziano C, Laghi L, Mariani P, Masiero S, Pieraccini S, Spada GP. The Supramolecular Helical Architecture of 8-Oxoinosine and 8-Oxoguanosine Derivatives. Chemistry 2007; 13:3441-9. [PMID: 17225218 DOI: 10.1002/chem.200601126] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The 8-oxoguanosine derivative 1 and the 8-oxoinosine derivative 2 b, with appropriate substituents on their ribose moieties, form hexagonal lyotropic mesophases in hydrocarbon solvents. Small-angle X-ray scattering analysis of a film of 1 and of the mesophase of 2 b, and NMR and CD spectra of isotropic solutions of 2 b, indicate that in both cases the supramolecular structures adopted are continuous helices formed by a hydrogen-bond network between the heterocyclic bases. Notably, while derivative 2 b, which bears large substituents on its ribose moiety, undergoes self-assembly and mesophase formation, oxoinosine 2 a, with only decanoyl groups on its ribose moiety, does not. This may be ascribed to the reduced amphiphilic properties of the latter and the absence of aromatic groups.
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Affiliation(s)
- Stefano Lena
- Alma Mater Studiorum-Università di Bologna, Dipartimento di Chimica Organica "A. Mangini", Via San Giacomo 11, 40126 Bologna, Italy
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33
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Kwan ICM, Mo X, Wu G. Probing Hydrogen Bonding and Ion−Carbonyl Interactions by Solid-State 17O NMR Spectroscopy: G-Ribbon and G-Quartet. J Am Chem Soc 2007; 129:2398-407. [PMID: 17269776 DOI: 10.1021/ja067991m] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report solid-state 17O NMR determination of the 17O NMR tensors for the keto carbonyl oxygen (O6) of guanine in two 17O-enriched guanosine derivatives: [6-17O]guanosine (G1) and 2',3',5'-O-triacetyl-[6-17O]guanosine (G2). In G1.2H2O, guanosine molecules form hydrogen-bonded G-ribbons where the guanine bases are linked by O6...H-N2 and N7...H-N7 hydrogen bonds in a zigzag fashion. In addition, the keto carbonyl oxygen O6 is also weakly hydrogen-bonded to two water molecules of hydration. The experimental 17O NMR tensors determined for the two independent molecules in the asymmetric unit of G1.2H2O are: Molecule A, CQ=7.8+/-0.1 MHz, etaQ=0.45+/-0.05, deltaiso=263+/-2, delta11=460+/-5, delta22=360+/-5, delta33=-30+/-5 ppm; Molecule B, CQ=7.7+/-0.1 MHz, etaQ=0.55+/-0.05, deltaiso=250+/-2, delta11=440+/-5, delta22=340+/-5, delta33=-30+/-5 ppm. In G1/K+ gel, guanosine molecules form extensively stacking G-quartets. In each G-quartet, four guanine bases are linked together by four pairs of O6...H-N1 and N7...H-N2 hydrogen bonds in a cyclic fashion. In addition, each O6 atom is simultaneously coordinated to two K+ ions. For G1/K+ gel, the experimental 17O NMR tensors are: CQ=7.2+/-0.1 MHz, etaQ=0.68+/-0.05, deltaiso=232+/-2, delta11=400+/-5, delta22=300+/-5, delta33=-20+/-5 ppm. In the presence of divalent cations such as Sr2+, Ba2+, and Pb2+, G2 molecules form discrete octamers containing two stacking G-quartets and a central metal ion, that is, (G2)4-M2+-(G2)4. In this case, each O6 atom of the G-quartet is coordinated to only one metal ion. For G2/M2+ octamers, the experimental 17O NMR parameters are: Sr2+, CQ=6.8+/-0.1 MHz, etaQ=1.00+/-0.05, deltaiso=232+/-2 ppm; Ba2+, CQ=7.0+/-0.1 MHz, etaQ=0.68+/-0.05, deltaiso=232+/-2 ppm; Pb2+, CQ=7.2+/-0.1 MHz, etaQ=1.00+/-0.05, deltaiso=232+/-2 ppm. We also perform extensive quantum chemical calculations for the 17O NMR tensors in both G-ribbons and G-quartets. Our results demonstrate that the 17O chemical shift tensor and quadrupole coupling tensor are very sensitive to the presence of hydrogen bonding and ion-carbonyl interactions. Furthermore, the effect from ion-carbonyl interactions is several times stronger than that from hydrogen-bonding interactions. Our results establish a basis for using solid-state 17O NMR as a probe in the study of ion binding in G-quadruplex DNA and ion channel proteins.
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Affiliation(s)
- Irene C M Kwan
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6
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34
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Pham TN, Griffin JM, Masiero S, Lena S, Gottarelli G, Hodgkinson P, Filip C, Brown SP. Quantifying hydrogen-bonding strength: the measurement of 2hJNN couplings in self-assembled guanosines by solid-state 15N spin-echo MAS NMR. Phys Chem Chem Phys 2007; 9:3416-23. [PMID: 17664965 DOI: 10.1039/b703513f] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
(2h)J(NN) hydrogen-bond mediated J couplings are measured in the solid state for two synthetic deoxyguanosine derivatives by (15)N MAS NMR spin-echo experiments. The use of rotor-synchronised Hahn-echo pulse train (RS-HEPT) (1)H decoupling, with a duty cycle of 6%, allows spin-echo durations out to 200 ms, hence enabling the accurate determination of J couplings as small as 3.8 Hz. A single-crystal X-ray diffraction structure exists for the shorter alkyl chain derivative dG(C(3))(2): the observation of significantly different (2h)J(NN) couplings, 6.2 +/- 0.4 and 7.4 +/- 0.4 Hz, for the two resolved N7 resonances is to be expected given the NH...N hydrogen-bonding distances of 2.91 and 2.83 A for the two distinct molecules in the asymmetric unit cell. For the longer alkyl chain derivative, dG(C(10))(2), for which there is no single-crystal diffraction structure, a (15)N refocused INADEQUATE spectrum (Pham et al., J. Am. Chem. Soc., 2005, 127, 16018-16019) has demonstrated the presence of N2-H...N7 intermolecular hydrogen-bonds indicative of a quartet-like structure. The (2h)J(NN) hydrogen-bond mediated J coupling of 5.9 +/- 0.2 Hz is at the lower end of the range (5.9-8.2 Hz) of (2h)J(NN) couplings determined from solution-state NMR of guanosine quartets in quadruplex DNA. A full discussion of the determination of error bars on the fitted parameters is given; specifically, error bars determined by a non-linear fitting (using the covariance matrix) or in a Monte-Carlo fashion are found to give effectively identical results.
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Affiliation(s)
- Tran N Pham
- Department of Physics, University of Warwick, Coventry, UK CV4 7AL
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Cadars S, Lesage A, Trierweiler M, Heux L, Emsley L. NMR measurements of scalar-coupling distributions in disordered solids. Phys Chem Chem Phys 2007; 9:92-103. [PMID: 17164890 DOI: 10.1039/b611096g] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The measurement of scalar (J) couplings by solid-state NMR is a field of great interest, since this interaction is a rich source of local structural information, complementary to dipolar and chemical shift interactions. Here, we first demonstrate that J-coupling distributions exist and can be observed in disordered solids, as illustrated with the observation of a pair-specific distribution of (2)J((31)P-N-(31)P) couplings in a bis-phosphino amine, and we investigate the potential effects of such distributions on the measurement of average J-coupling constants. Second, we show that the measurement of two-dimensional (2D) distributions of J-couplings provides a much richer probe of local structural disorder than one-dimensional distributions, and we introduce new methods that provide different (selective or non-selective) ways of measuring 2D J distributions in a wide range of disordered systems. These methods are finally applied to a slightly disordered polymorphic sample of fully (13)C-enriched cellulose, and then to the bis-phosphino amine sample, from which 2D (2)J(PP)-coupling distributions are clearly identified and interpreted.
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Affiliation(s)
- Sylvian Cadars
- Laboratoire de Chimie (UMR 5182 CNRS/ENS Lyon), Ecole Normale Supérieure de Lyon, Lyon, France
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