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Jean-paul Amoureux - One of the best experts on this subject based on the ideXlab platform.
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Broadband Homonuclear Correlation spectroscopy driven by combined R2nv sequences under fast magic angle spinning for NMR structural analysis of organic and biological solids
Journal of magnetic resonance (San Diego Calif. : 1997), 2013Co-Authors: Guangjin Hou, Jean-paul Amoureux, Julien Trébosc, Si Yan, Tatyana PolenovaAbstract:Abstract We recently described a family of experiments for R 2 n v Driven Spin Diffusion (RDSD) spectroscopy suitable for Homonuclear Correlation experiments under fast MAS conditions [G. Hou, S. Yan, S.J. Sun, Y. Han, I.J. Byeon, J. Ahn, J. Concel, A. Samoson, A.M. Gronenborn, T. Polenova, Spin diffusion drive by R-symmetry sequencs: applications to Homonuclear Correlation spectroscopy in MAS NMR of biological and organic solids, J. Am. Chem. Soc. 133 (2011) 3943–3953]. In these RDSD experiments, since the broadened second-order rotational resonance conditions are dominated by the radio frequency field strength and the phase shifts, as well as the size of reintroduced dipolar couplings, the different R 2 n v sequences display unique polarization transfer behaviors and different recoupling frequency bandwidths. Herein, we present a series of modified R 2 n v sequences, dubbed COmbined R 2 n v -Driven (CORD), that yield broadband Homonuclear dipolar recoupling and give rise to uniform distribution of cross peak intensities across the entire Correlation spectrum. We report NMR experiments and numerical simulations demonstrating that these CORD spin diffusion sequences are suitable for broadband recoupling at a wide range of magnetic fields and MAS frequencies, including fast-MAS conditions (νr = 40 kHz and above). Since these CORD sequences are largely insensitive to dipolar truncation, they are well suited for the determination of long-range distance constraints, which are indispensable for the structural characterization of a broad range of systems. Using U-13C,15N-alanine and U–13C,15N-histidine, we show that under fast-MAS conditions, the CORD sequences display polarization transfer efficiencies within broadband frequency regions that are generally higher than those offered by other existing spin diffusion pulse schemes. A 89-residue U–13C,15N-dynein light chain (LC8) protein has also been used to demonstrate that the CORD sequences exhibit uniformly high cross peak intensities across the entire chemical shift range.
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double quantum nmr spectroscopy of 31p species submitted to very large csas
Journal of Magnetic Resonance, 2009Co-Authors: Laurent Delevoye, Julien Trébosc, Olivier Lafon, Jean-paul AmoureuxAbstract:Abstract We introduce an original pulse sequence, BR 2 2 1 ( τ π τ ) , which is a block super-cycled R 2 2 1 sequence employing as basic element a π pulse sandwiched by ‘window’ intervals. This Homonuclear dipolar recoupling method allows the efficient excitation of double-quantum coherences between spin-1/2 nuclei submitted to very large chemical shift anisotropy. We demonstrate that this technique can be employed in double-quantum ↔ single-quantum 31 P Homonuclear Correlation experiment at high magnetic field ( B 0 ⩾ 14 T) and high MAS frequencies ( ν R ⩾ 30 kHz). The performances of BR 2 2 1 ( τ π τ ) are compared to those of the double-quantum recoupling methods, such as BABA and bracketed fp-RFDR, which were already employed at fast MAS rates. The BR 2 2 1 ( τ π τ ) sequence displays a higher robustness to CSA and offset than the other existing techniques.
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Solid-state NMR covariance of Homonuclear Correlation spectra.
The Journal of chemical physics, 2008Co-Authors: Jean-paul Amoureux, Julien Trébosc, Michaël Deschamps, Grégory TricotAbstract:Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain Homonuclear Correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin −1∕2 nuclei with C13, Si29, and P31 through-space or through-bond Homonuclear 2D Correlation spec...
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Solid-state NMR covariance of Homonuclear Correlation spectra
Journal of Chemical Physics, 2008Co-Authors: Jean-paul Amoureux, Julien Trébosc, Michaël Deschamps, Grégory TricotAbstract:Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain Homonuclear Correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin -12 nuclei with C13, Si29, and P31 through-space or through-bond Homonuclear 2D Correlation spectra. In all cases, the experimental time has been reduced by at least a factor of 10, without any loss of resolution and signal to noise ratio, with respect to what is necessary with the 2D-FT NMR. According to this method, we have been able to study the silicate network of glasses by 2D NMR within reasonable experimental time despite the very long relaxation time of the Si29 nucleus. The main limitation of the 2D-Cov data treatment is related to the introduction of autocorrelated peaks onto the diagonal, which does not represent any actual connectivity.
Michaël Deschamps - One of the best experts on this subject based on the ideXlab platform.
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Solid-state NMR covariance of Homonuclear Correlation spectra.
The Journal of chemical physics, 2008Co-Authors: Jean-paul Amoureux, Julien Trébosc, Michaël Deschamps, Grégory TricotAbstract:Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain Homonuclear Correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin −1∕2 nuclei with C13, Si29, and P31 through-space or through-bond Homonuclear 2D Correlation spec...
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Solid-state NMR covariance of Homonuclear Correlation spectra
Journal of Chemical Physics, 2008Co-Authors: Jean-paul Amoureux, Julien Trébosc, Michaël Deschamps, Grégory TricotAbstract:Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain Homonuclear Correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin -12 nuclei with C13, Si29, and P31 through-space or through-bond Homonuclear 2D Correlation spectra. In all cases, the experimental time has been reduced by at least a factor of 10, without any loss of resolution and signal to noise ratio, with respect to what is necessary with the 2D-FT NMR. According to this method, we have been able to study the silicate network of glasses by 2D NMR within reasonable experimental time despite the very long relaxation time of the Si29 nucleus. The main limitation of the 2D-Cov data treatment is related to the introduction of autocorrelated peaks onto the diagonal, which does not represent any actual connectivity.
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through bond Homonuclear Correlation experiments in solid state nmr applied to quadrupolar nuclei in al o p o al chains
Chemical Communications, 2006Co-Authors: Michaël Deschamps, Franck Fayon, Valerie Montouillout, Dominique MassiotAbstract:Through-bond Homonuclear Correlation experiments can be realised in solids between spins of type X, separated by four chemical bonds, in X–O–Y–O–X motifs, provided a J coupling between X and Y exists: central transitions of quadrupolar 27Al spins can be correlated via the J2 scalar coupling between 27Al (X) and 31P (Y) in materials featuring Al–O–P–O–Al motifs.
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Through-bond Homonuclear Correlation experiments in solid-state NMR applied to quadrupolar nuclei in Al–O–P–O–Al chains
Chemical communications (Cambridge England), 2006Co-Authors: Michaël Deschamps, Franck Fayon, Valerie Montouillout, Dominique MassiotAbstract:Through-bond Homonuclear Correlation experiments can be realised in solids between spins of type X, separated by four chemical bonds, in X–O–Y–O–X motifs, provided a J coupling between X and Y exists: central transitions of quadrupolar 27Al spins can be correlated via the J2 scalar coupling between 27Al (X) and 31P (Y) in materials featuring Al–O–P–O–Al motifs.
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Through-bond Homonuclear Correlation experiments in Solid-state NMR applied to quadrupolar nuclei in Al-O-P-O-Al chains.
Chemical Communications, 2006Co-Authors: Michaël Deschamps, Franck Fayon, Valerie Montouillout, Dominique MassiotAbstract:Through-bond Homonuclear Correlation experiments can be realised in solids between spins of type X, separated by four chemical bonds, in X-O-Y-O-X motives, provided a J coupling 10 between X and Y exists: central transitions of quadrupolar 27Al spins can be correlated via the J2 scalar coupling between 27Al (X) and 31P (Y) in materials featuring Al-O-P-O-Al motives.
Grégory Tricot - One of the best experts on this subject based on the ideXlab platform.
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Solid-state NMR covariance of Homonuclear Correlation spectra.
The Journal of chemical physics, 2008Co-Authors: Jean-paul Amoureux, Julien Trébosc, Michaël Deschamps, Grégory TricotAbstract:Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain Homonuclear Correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin −1∕2 nuclei with C13, Si29, and P31 through-space or through-bond Homonuclear 2D Correlation spec...
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Solid-state NMR covariance of Homonuclear Correlation spectra
Journal of Chemical Physics, 2008Co-Authors: Jean-paul Amoureux, Julien Trébosc, Michaël Deschamps, Grégory TricotAbstract:Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain Homonuclear Correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin -12 nuclei with C13, Si29, and P31 through-space or through-bond Homonuclear 2D Correlation spectra. In all cases, the experimental time has been reduced by at least a factor of 10, without any loss of resolution and signal to noise ratio, with respect to what is necessary with the 2D-FT NMR. According to this method, we have been able to study the silicate network of glasses by 2D NMR within reasonable experimental time despite the very long relaxation time of the Si29 nucleus. The main limitation of the 2D-Cov data treatment is related to the introduction of autocorrelated peaks onto the diagonal, which does not represent any actual connectivity.
Julien Trébosc - One of the best experts on this subject based on the ideXlab platform.
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Broadband Homonuclear Correlation spectroscopy driven by combined R2nv sequences under fast magic angle spinning for NMR structural analysis of organic and biological solids
Journal of magnetic resonance (San Diego Calif. : 1997), 2013Co-Authors: Guangjin Hou, Jean-paul Amoureux, Julien Trébosc, Si Yan, Tatyana PolenovaAbstract:Abstract We recently described a family of experiments for R 2 n v Driven Spin Diffusion (RDSD) spectroscopy suitable for Homonuclear Correlation experiments under fast MAS conditions [G. Hou, S. Yan, S.J. Sun, Y. Han, I.J. Byeon, J. Ahn, J. Concel, A. Samoson, A.M. Gronenborn, T. Polenova, Spin diffusion drive by R-symmetry sequencs: applications to Homonuclear Correlation spectroscopy in MAS NMR of biological and organic solids, J. Am. Chem. Soc. 133 (2011) 3943–3953]. In these RDSD experiments, since the broadened second-order rotational resonance conditions are dominated by the radio frequency field strength and the phase shifts, as well as the size of reintroduced dipolar couplings, the different R 2 n v sequences display unique polarization transfer behaviors and different recoupling frequency bandwidths. Herein, we present a series of modified R 2 n v sequences, dubbed COmbined R 2 n v -Driven (CORD), that yield broadband Homonuclear dipolar recoupling and give rise to uniform distribution of cross peak intensities across the entire Correlation spectrum. We report NMR experiments and numerical simulations demonstrating that these CORD spin diffusion sequences are suitable for broadband recoupling at a wide range of magnetic fields and MAS frequencies, including fast-MAS conditions (νr = 40 kHz and above). Since these CORD sequences are largely insensitive to dipolar truncation, they are well suited for the determination of long-range distance constraints, which are indispensable for the structural characterization of a broad range of systems. Using U-13C,15N-alanine and U–13C,15N-histidine, we show that under fast-MAS conditions, the CORD sequences display polarization transfer efficiencies within broadband frequency regions that are generally higher than those offered by other existing spin diffusion pulse schemes. A 89-residue U–13C,15N-dynein light chain (LC8) protein has also been used to demonstrate that the CORD sequences exhibit uniformly high cross peak intensities across the entire chemical shift range.
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double quantum nmr spectroscopy of 31p species submitted to very large csas
Journal of Magnetic Resonance, 2009Co-Authors: Laurent Delevoye, Julien Trébosc, Olivier Lafon, Jean-paul AmoureuxAbstract:Abstract We introduce an original pulse sequence, BR 2 2 1 ( τ π τ ) , which is a block super-cycled R 2 2 1 sequence employing as basic element a π pulse sandwiched by ‘window’ intervals. This Homonuclear dipolar recoupling method allows the efficient excitation of double-quantum coherences between spin-1/2 nuclei submitted to very large chemical shift anisotropy. We demonstrate that this technique can be employed in double-quantum ↔ single-quantum 31 P Homonuclear Correlation experiment at high magnetic field ( B 0 ⩾ 14 T) and high MAS frequencies ( ν R ⩾ 30 kHz). The performances of BR 2 2 1 ( τ π τ ) are compared to those of the double-quantum recoupling methods, such as BABA and bracketed fp-RFDR, which were already employed at fast MAS rates. The BR 2 2 1 ( τ π τ ) sequence displays a higher robustness to CSA and offset than the other existing techniques.
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Solid-state NMR covariance of Homonuclear Correlation spectra.
The Journal of chemical physics, 2008Co-Authors: Jean-paul Amoureux, Julien Trébosc, Michaël Deschamps, Grégory TricotAbstract:Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain Homonuclear Correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin −1∕2 nuclei with C13, Si29, and P31 through-space or through-bond Homonuclear 2D Correlation spec...
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Solid-state NMR covariance of Homonuclear Correlation spectra
Journal of Chemical Physics, 2008Co-Authors: Jean-paul Amoureux, Julien Trébosc, Michaël Deschamps, Grégory TricotAbstract:Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain Homonuclear Correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin -12 nuclei with C13, Si29, and P31 through-space or through-bond Homonuclear 2D Correlation spectra. In all cases, the experimental time has been reduced by at least a factor of 10, without any loss of resolution and signal to noise ratio, with respect to what is necessary with the 2D-FT NMR. According to this method, we have been able to study the silicate network of glasses by 2D NMR within reasonable experimental time despite the very long relaxation time of the Si29 nucleus. The main limitation of the 2D-Cov data treatment is related to the introduction of autocorrelated peaks onto the diagonal, which does not represent any actual connectivity.
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Solid-state NMR study of MCM-41-type mesoporous silica nanoparticles.
Journal of the American Chemical Society, 2005Co-Authors: Julien Trébosc, Jerzy W. Wiench, Seong Huh, Victor S.-y. Lin, Marek PruskiAbstract:A systematic study of the surface of MCM-41-type mesoporous silica nanoparticles prepared under low surfactant concentration was carried out using high-resolution solid-state nuclear magnetic resonance spectroscopy. The structures and concentrations of various species present during dehydration and rehydration of mesoporous silicas between −25 and 500 °C were detailed by employing one-dimensional and two-dimensional 1H, 13C, and 29Si NMR, including 1H signal intensity measurements, 1H−1H Homonuclear Correlation experiments (double quantum, exchange, and RFDR), and 1H−29Si heteronuclear Correlation NMR. These experiments employed high MAS rates of up to 45 kHz. The study shows that the surfactant (CTAB) was almost completely removed by acid extraction. The residual molecules assumed prone positions along the pores, with the tailgroup being most mobile. The weakly adsorbed water was hydrogen bonded to the silanol groups, all of which were involved in such bonds under ambient humidity. Specific structures in...
Barth-jan Van Rossum - One of the best experts on this subject based on the ideXlab platform.
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Spectral editing: selection of methyl groups in multidimensional solid-state magic-angle spinning NMR
Journal of Biomolecular NMR, 2006Co-Authors: Stefan Jehle, Matthias Hiller, Kristina Rehbein, Anne Diehl, Hartmut Oschkinat, Barth-jan Van RossumAbstract:A simple spectroscopic filtering technique is presented that may aid the assignment of 13C and 15N resonances of methyl-containing amino-acids in solid-state magic-angle spinning (MAS) NMR. A filtering block that selects methyl resonances is introduced in two-dimensional (2D) 13C-Homonuclear and 15N–13C heteronuclear Correlation experiments. The 2D 13C–13C Correlation spectra are recorded with the methyl filter implemented prior to a 13C–13C mixing step. It is shown that these methyl-filtered 13C-Homonuclear Correlation spectra are instrumental in the assignment of Cδ resonances of leucines by suppression of Cγ–Cδ cross peaks. Further, a methyl filter is implemented prior to a 15N–13C transferred-echo double resonance (TEDOR) exchange scheme to obtain 2D 15N–13C heteronuclear Correlation spectra. These experiments provide Correlations between methyl groups and backbone amides. Some of the observed sequential 15N–13C Correlations form the basis for initial sequence-specific assignments of backbone signals of the outer-membrane protein G.
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Spectral editing: selection of methyl groups in multidimensional solid-state magic-angle spinning NMR
Journal of Biomolecular NMR, 2006Co-Authors: Stefan Jehle, Matthias Hiller, Kristina Rehbein, Anne Diehl, Hartmut Oschkinat, Barth-jan Van RossumAbstract:A simple spectroscopic filtering technique is presented that may aid the assignment of 13C and 15N resonances of methyl-containing amino-acids in solid-state magic-angle spinning (MAS) NMR. A filtering block that selects methyl resonances is introduced in two-dimensional (2D) 13C-Homonuclear and 15N–13C heteronuclear Correlation experiments. The 2D 13C–13C Correlation spectra are recorded with the methyl filter implemented prior to a 13C–13C mixing step. It is shown that these methyl-filtered 13C-Homonuclear Correlation spectra are instrumental in the assignment of Cδ resonances of leucines by suppression of Cγ–Cδ cross peaks. Further, a methyl filter is implemented prior to a 15N–13C transferred-echo double resonance (TEDOR) exchange scheme to obtain 2D 15N–13C heteronuclear Correlation spectra. These experiments provide Correlations between methyl groups and backbone amides. Some of the observed sequential 15N–13C Correlations form the basis for initial sequence-specific assignments of backbone signals of the outer-membrane protein G.