1
|
Zhang R, Mroue KH, Ramamoorthy A. Proton chemical shift tensors determined by 3D ultrafast MAS double-quantum NMR spectroscopy. J Chem Phys 2015; 143:144201. [PMID: 26472372 PMCID: PMC4608963 DOI: 10.1063/1.4933114] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 10/01/2015] [Indexed: 12/18/2022] Open
Abstract
Proton NMR spectroscopy in the solid state has recently attracted much attention owing to the significant enhancement in spectral resolution afforded by the remarkable advances in ultrafast magic angle spinning (MAS) capabilities. In particular, proton chemical shift anisotropy (CSA) has become an important tool for obtaining specific insights into inter/intra-molecular hydrogen bonding. However, even at the highest currently feasible spinning frequencies (110-120 kHz), (1)H MAS NMR spectra of rigid solids still suffer from poor resolution and severe peak overlap caused by the strong (1)H-(1)H homonuclear dipolar couplings and narrow (1)H chemical shift (CS) ranges, which render it difficult to determine the CSA of specific proton sites in the standard CSA/single-quantum (SQ) chemical shift correlation experiment. Herein, we propose a three-dimensional (3D) (1)H double-quantum (DQ) chemical shift/CSA/SQ chemical shift correlation experiment to extract the CS tensors of proton sites whose signals are not well resolved along the single-quantum chemical shift dimension. As extracted from the 3D spectrum, the F1/F3 (DQ/SQ) projection provides valuable information about (1)H-(1)H proximities, which might also reveal the hydrogen-bonding connectivities. In addition, the F2/F3 (CSA/SQ) correlation spectrum, which is similar to the regular 2D CSA/SQ correlation experiment, yields chemical shift anisotropic line shapes at different isotropic chemical shifts. More importantly, since the F2/F1 (CSA/DQ) spectrum correlates the CSA with the DQ signal induced by two neighboring proton sites, the CSA spectrum sliced at a specific DQ chemical shift position contains the CSA information of two neighboring spins indicated by the DQ chemical shift. If these two spins have different CS tensors, both tensors can be extracted by numerical fitting. We believe that this robust and elegant single-channel proton-based 3D experiment provides useful atomistic-level structural and dynamical information for a variety of solid systems that possess high proton density.
Collapse
Affiliation(s)
- Rongchun Zhang
- Biophysics and Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| | - Kamal H Mroue
- Biophysics and Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| |
Collapse
|
2
|
Zhang R, Ramamoorthy A. Selective excitation enables assignment of proton resonances and (1)H-(1)H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy. J Chem Phys 2015; 143:034201. [PMID: 26203019 PMCID: PMC4506299 DOI: 10.1063/1.4926834] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/03/2015] [Indexed: 11/14/2022] Open
Abstract
Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of (1)H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as (13)C or (15)N. In this method, after the initial preparation of proton magnetization and cross-polarization to (13)C nuclei, transverse magnetization of desired (13)C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific (13)C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of (1)H-(1)H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.
Collapse
Affiliation(s)
- Rongchun Zhang
- Biophysics and Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| |
Collapse
|
3
|
Pichumani K, George G, Hebbar S, Chatterjee B, Raghothama S. Effects of hydrogen bonding on amide-proton chemical shift anisotropy in a proline-containing model peptide. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.03.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
4
|
Pandey MK, Malon M, Ramamoorthy A, Nishiyama Y. Composite-180° pulse-based symmetry sequences to recouple proton chemical shift anisotropy tensors under ultrafast MAS solid-state NMR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 250:45-54. [PMID: 25497846 PMCID: PMC4301976 DOI: 10.1016/j.jmr.2014.11.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/03/2014] [Accepted: 11/04/2014] [Indexed: 05/17/2023]
Abstract
There is considerable interest in the measurement of proton ((1)H) chemical shift anisotropy (CSA) tensors to obtain deeper insights into H-bonding interactions which find numerous applications in chemical and biological systems. However, the presence of strong (1)H/(1)H dipolar interaction makes it difficult to determine small size (1)H CSAs from the homogeneously broadened NMR spectra. Previously reported pulse sequences for (1)H CSA recoupling are prone to the effects of radio frequency field (B1) inhomogeneity. In the present work we have carried out a systematic study using both numerical and experimental approaches to evaluate γ-encoded radio frequency (RF) pulse sequences based on R-symmetries that recouple (1)H CSA in the indirect dimension of a 2D (1)H/(1)H anisotropic/isotropic chemical shift correlation experiment under ultrafast magic angle spinning (MAS) frequencies. The spectral resolution and sensitivity can be significantly improved in both frequency dimensions of the 2D (1)H/(1)H correlation spectrum without decoupling (1)H/(1)H dipolar couplings but by using ultrafast MAS rates up to 70 kHz. We successfully demonstrate that with a reasonable RF field requirement (<200 kHz) a set of symmetry-based recoupling sequences, with a series of phase-alternating 270°0-90°180 composite-180° pulses, are more robust in combating B1 inhomogeneity effects. In addition, our results show that the new pulse sequences render remarkable (1)H CSA recoupling efficiency and undistorted CSA lineshapes. Experimental results on citric acid and malonic acid comparing the efficiencies of these newly developed pulse sequences with that of previously reported CSA recoupling pulse sequences are also reported under ultrafast MAS conditions.
Collapse
Affiliation(s)
| | - Michal Malon
- CLST NMR Facility, RIKEN, Yokohama, Kanagawa 230-0045, Japan; JEOL RESONANCE Inc., Musashino, Akishima, Tokyo 196-8558, Japan
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Yusuke Nishiyama
- CLST NMR Facility, RIKEN, Yokohama, Kanagawa 230-0045, Japan; JEOL RESONANCE Inc., Musashino, Akishima, Tokyo 196-8558, Japan.
| |
Collapse
|
5
|
Fu R, Gordon ED, Hibbard DJ, Cotten M. High resolution heteronuclear correlation NMR spectroscopy of an antimicrobial peptide in aligned lipid bilayers: peptide-water interactions at the water-bilayer interface. J Am Chem Soc 2009; 131:10830-1. [PMID: 19621928 DOI: 10.1021/ja903999g] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High-resolution two-dimensional (2D) (1)H-(15)N heteronuclear correlation (HETCOR) spectroscopy has been used to characterize the structure and dynamics of (15)N-backbone labeled antimicrobial piscidin 1 (p1) oriented in "native-like" hydrated lipid bilayers. Piscidin belongs to a family of amphipatic cationic antimicrobial peptides, which are membrane-active and have broad spectrum antimicrobial activity on bacteria. When the (1)H chemical shifts are encoded by the (1)H-(15)N dipolar couplings, 2D dipolar-encoded HETCOR (i.e., de-HETCOR) solid-state NMR spectra yield high resolution (1)H and (15)N chemical shifts as well as (1)H-(15)N heteronuclear dipolar couplings. Several advantages of HETCOR and de-HETCOR techniques that emerge from our investigations could facilitate the atomic-level investigations of structure-function relationships in membrane-active peptides and membrane-bound species. First, the de-HETCOR NMR spectrum of a ten-site (15)N-labeled sample of p1 aligned in hydrated lipid bilayers can resolve resonances that are overlapped in the standard HETCOR spectrum. Second, the resolution in de-HETCOR spectra of p1 improves significantly at higher magnetic field due to an enhanced alignment that improves spectrum definition uniformly. Third, the HETCOR spectrum of (15)N-K(14) p1 oriented in hydrated lipid bilayers displays not only the expected crosscorrelation between the chemical shifts of bonded amide(1)H and (15)N spins but also a cross peak between the (1)H chemical shift from bulk water and the (15)N chemical shift from the labeled amide nitrogen. This information provides new insights into the intermolecular interactions of an amphipathic antimicrobial peptide optimized to partition at the water-bilayer interface and may have implications at the biological level.
Collapse
Affiliation(s)
- Riqiang Fu
- National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, USA.
| | | | | | | |
Collapse
|
6
|
Suzuki Y, Takahashi R, Shimizu T, Tansho M, Yamauchi K, Williamson MP, Asakura T. Intra- and Intermolecular Effects on 1H Chemical Shifts in a Silk Model Peptide Determined by High-Field Solid State 1H NMR and Empirical Calculations. J Phys Chem B 2009; 113:9756-61. [DOI: 10.1021/jp903020p] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yu Suzuki
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan, National Institute for Material Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank Sheffield S10 2TN, U.K
| | - Rui Takahashi
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan, National Institute for Material Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank Sheffield S10 2TN, U.K
| | - Tadashi Shimizu
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan, National Institute for Material Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank Sheffield S10 2TN, U.K
| | - Masataka Tansho
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan, National Institute for Material Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank Sheffield S10 2TN, U.K
| | - Kazuo Yamauchi
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan, National Institute for Material Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank Sheffield S10 2TN, U.K
| | - Mike P. Williamson
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan, National Institute for Material Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank Sheffield S10 2TN, U.K
| | - Tetsuo Asakura
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan, National Institute for Material Science, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank Sheffield S10 2TN, U.K
| |
Collapse
|
7
|
Coelho C, Rocha J, Madhu PK, Mafra L. Practical aspects of Lee-Goldburg based CRAMPS techniques for high-resolution 1H NMR spectroscopy in solids: implementation and applications. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2008; 194:264-282. [PMID: 18703365 DOI: 10.1016/j.jmr.2008.07.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 07/15/2008] [Accepted: 07/18/2008] [Indexed: 05/26/2023]
Abstract
Elucidating the local environment of the hydrogen atoms is an important problem in materials science. Because (1)H spectra in solid-state nuclear magnetic resonance (NMR) suffer from low resolution due to homogeneous broadening, even under magic-angle spinning (MAS), information of chemical interest may only be obtained using certain high-resolution (1)H MAS techniques. (1)H Lee-Goldburg (LG) CRAMPS (Combined Rotation And Multiple-Pulse Spectroscopy) methods are particularly well suited for studying inorganic-organic hybrid materials, rich in (1)H nuclei. However, setting up CRAMPS experiments is time-consuming and not entirely trivial, facts that have discouraged their widespread use by materials scientists. To change this status quo, here we describe and discuss some important aspects of the experimental implementation of CRAMPS techniques based on LG decoupling schemes, such as FSLG (Frequency Switched), and windowed and windowless PMLG (Phase Modulated). In particular, we discuss the influence on the quality of the (1)H NMR spectra of the different parameters at play, for example LG (Lee-Goldburg) pulses, radio-frequency (rf) phase, frequency switching, and pulse imperfections, using glycine and adamantane as model compounds. The efficiency and robustness of the different LG-decoupling schemes is then illustrated on the following materials: organo-phosphorus ligand, N-(phosphonomethyl)iminodiacetic acid [H(4)pmida] [I], and inorganic-organic hybrid materials (C(4)H(12)N(2))[Ge(2)(pmida)(2)OH(2)] x 4H(2)O [II] and (C(2)H(5)NH(3))[Ti(H(1.5)PO(4))(PO(4))](2) x H(2)O [III].
Collapse
Affiliation(s)
- Cristina Coelho
- Department of Chemistry, CICECO, University of Aveiro, Aveiro, Portugal
| | | | | | | |
Collapse
|
8
|
Fu R, Truong M, Saager RJ, Cotten M, Cross TA. High-resolution heteronuclear correlation spectroscopy in solid state NMR of aligned samples. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2007; 188:41-8. [PMID: 17606394 DOI: 10.1016/j.jmr.2007.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 06/12/2007] [Accepted: 06/15/2007] [Indexed: 05/16/2023]
Abstract
A new two-dimensional scheme is proposed for accurate measurements of high-resolution chemical shifts and heteronuclear dipolar couplings in NMR of aligned samples. Both the (1)H chemical shifts and the (1)H-(15)N dipolar couplings are evolved in the indirect dimension while the (15)N chemical shifts are detected. This heteronuclear correlation (HETCOR) spectroscopy yields high-resolution (1)H chemical shifts split by the (1)H-(15)N dipolar couplings in the indirect dimension and the (15)N chemical shifts in the observed dimension. The advantages of the HETCOR technique are illustrated for a static (15)N-acetyl-valine crystal sample and a (15)N-labeled helical peptide sample aligned in hydrated lipid bilayers.
Collapse
Affiliation(s)
- Riqiang Fu
- Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, FL 32310, USA.
| | | | | | | | | |
Collapse
|
9
|
Yamamoto K, Ermakov VL, Lee DK, Ramamoorthy A. PITANSEMA-MAS, a solid-state NMR method to measure heteronuclear dipolar couplings under MAS. Chem Phys Lett 2005; 408:118-122. [PMID: 16652173 PMCID: PMC1451416 DOI: 10.1016/j.cplett.2005.04.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A 2D NMR method is presented for the measurement of the dipole-dipole interaction between a proton and a low-frequency nuclear spin species in the solid state under the magic angle spinning. It employs the time averaged nutation concept to dramatically reduce the required radio frequency (rf) power on the low γ nuclear channel and spin exchange at the magic angle is used to suppress (1)H-(1)H dipolar interactions and chemical shifts. The flexibility in choosing the spinning speed, rf power and the scaling factor of the pulse sequence are of considerable importance for the structural studies of biological solids. The performance of the pulse sequence has been numerically and experimentally demonstrated on several solids.
Collapse
Affiliation(s)
- K Yamamoto
- Biophysics Research Division and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, United States
| | | | | | | |
Collapse
|
10
|
|
11
|
Lee D, Narasimhaswamy T, Ramamoorthy A. PITANSEMA, a low-power PISEMA solid-state NMR experiment. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.10.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
12
|
Shekar SC, Lee DK, Ramamoorthy A. Chemical shift anisotropy and offset effects in cross polarization solid-state NMR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2002; 157:223-234. [PMID: 12323141 DOI: 10.1006/jmre.2002.2587] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effect of an offset term in the cross-polarization (CP) Hamiltonian of a heteronuclear spin-12 pair due to off-resonant radio frequency (rf) irradiation and/or chemical shift anisotropy on one of the rf channels is investigated. Analytical solutions, simulations, and experimental results are presented. Formulating the CP spin dynamics in terms of an explicit unitary evolution operator enables the CP period to be inserted as a module in a given pulse scheme regardless of the initial density matrix present. The outcome of post-CP manipulation via pulses can be calculated on the resulting density matrix as the phases and amplitudes of all coherence modes are available. Using these tools it is shown that the offset can be used to reduce the rf power on that channel and the performance is further improved by a post-CP pulse whose flip angle matches and compensates the tilt of the effective field on the offset channel. Experimental investigations on single crystalline and polycrystalline samples of peptides confirm the oscillatory nature of CP dynamics and prove the slowing down of the dynamics under offset and/or mismatch conditions.
Collapse
Affiliation(s)
- Srinivasan C Shekar
- Department of Chemistry, Biophysics Research Division, and Macromolecular Science and Engineering, The University of Michigan, 930 N. University Avenue, Ann Arbor, 48109-1055, USA
| | | | | |
Collapse
|