The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Ramadurai Ramachandran - One of the best experts on this subject based on the ideXlab platform.
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MAS solid state NMR of proteins: simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling via low-power symmetry-based Rf Pulse schemes
Journal of Biomolecular NMR, 2015Co-Authors: Christian Herbst, Matthias Görlach, Peter Bellstedt, Ramadurai RamachandranAbstract:The generation of efficient RN_ n ^νs,^νk symmetry-based low-power Rf Pulse schemes for simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling is demonstrated. The method involves mixing schemes employing phase and amplitude-modulated dual band - selective 180° Pulses as basic “ R ” element and tailoring of the Rf field-modulation profile of the 180° Pulses so as to obtain efficient magnetisation transfer characteristics over the resonance offset range of the nuclei involved. Mixing schemes leading to simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling would permit the one-shot acquisition of different chemical shift correlation spectra that are typically utilized for protein backbone resonance assignments and thereby save data acquisition time. At representative MAS frequencies the efficacies of the mixing schemes presented here have been experimentally demonstrated via the simultaneous acquisition of {3D CONH and 3D CANH}, {3D CONH and 3D CO(CA)NH} and {3D CONH, 3D CANH, 3D CO(CA)NH and 3D CA(CO)NH} spectra generated via the magnetisation transfer pathways ^1H → ^13CO → ^15N → ^1H (CONH), ^1H → ^13CA → ^15N → ^1H (CANH) and ^1H → ^13CO → ^13CA → ^15N → ^1H (CO(CA)NH) and ^1H → ^13CA → ^13CO → ^15N → ^1H (CA(CO)NH).
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mas solid state nmr of proteins simultaneous 15n 13ca and 15n 13co dipolar recoupling via low power symmetry based Rf Pulse schemes
Journal of Biomolecular NMR, 2015Co-Authors: Christian Herbst, Matthias Görlach, Peter Bellstedt, Ramadurai RamachandranAbstract:The generation of efficient RN n (ν)s,(ν)k symmetry-based low-power Rf Pulse schemes for simultaneous (15)N-(13)CA and (15)N-(13)CO dipolar recoupling is demonstrated. The method involves mixing schemes employing phase and amplitude-modulated dual band-selective 180° Pulses as basic "R" element and tailoring of the Rf field-modulation profile of the 180° Pulses so as to obtain efficient magnetisation transfer characteristics over the resonance offset range of the nuclei involved. Mixing schemes leading to simultaneous (15)N-(13)CA and (15)N-(13)CO dipolar recoupling would permit the one-shot acquisition of different chemical shift correlation spectra that are typically utilized for protein backbone resonance assignments and thereby save data acquisition time. At representative MAS frequencies the efficacies of the mixing schemes presented here have been experimentally demonstrated via the simultaneous acquisition of {3D CONH and 3D CANH}, {3D CONH and 3D CO(CA)NH} and {3D CONH, 3D CANH, 3D CO(CA)NH and 3D CA(CO)NH} spectra generated via the magnetisation transfer pathways (1)H → (13)CO → (15)N → (1)H (CONH), (1)H → (13)CA → (15)N → (1)H (CANH) and (1)H → (13)CO → (13)CA → (15)N → (1)H (CO(CA)NH) and (1)H → (13)CA → (13)CO → (15)N → (1)H (CA(CO)NH).
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Broadband ^15N–^13C dipolar recoupling via symmetry-based Rf Pulse schemes at high MAS frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient $$ {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} $$ symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband ^15N–^13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “ R ” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “ R ” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and ^15N–^13C chemical shift correlation experiments. Employing such ^13C–^15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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broadband 15n 13c dipolar recoupling via symmetry based Rf Pulse schemes at high mas frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient \( {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} \) symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband 15N–13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “R” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “R” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and 15N–13C chemical shift correlation experiments. Employing such 13C–15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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Recoupling and decoupling of nuclear spin interactions at high MAS frequencies: numerical design of CN _ n ^ν symmetry-based Rf Pulse schemes
Journal of Biomolecular NMR, 2009Co-Authors: Christian Herbst, Jirada Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Anika Kirschstein, Ramadurai RamachandranAbstract:The CN _ n ^ν class of Rf Pulse schemes, commonly employed for recoupling and decoupling of nuclear spin interactions in magic angle spinning solid state NMR studies of biological systems, involves the application of a basic “ C ” element corresponding to an Rf cycle with unity propagator. In this study, the design of CN _ n ^ν symmetry-based Rf Pulse sequences for achieving ^13C–^13C double-quantum dipolar recoupling and through bond scalar coupling mediated ^13C–^13C chemical shift correlation has been examined at high MAS frequencies employing broadband, constant-amplitude, phase-modulated basic “ C ” elements. The basic elements were implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by an Rf phase value. The phase-modulation profile of the “ C ” element was optimised numerically so as to generate efficient Rf Pulse sequences. The peRformances of the sequences were evaluated via numerical simulations and experimental measurements and are presented here.
Christian Herbst - One of the best experts on this subject based on the ideXlab platform.
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MAS solid state NMR of proteins: simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling via low-power symmetry-based Rf Pulse schemes
Journal of Biomolecular NMR, 2015Co-Authors: Christian Herbst, Matthias Görlach, Peter Bellstedt, Ramadurai RamachandranAbstract:The generation of efficient RN_ n ^νs,^νk symmetry-based low-power Rf Pulse schemes for simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling is demonstrated. The method involves mixing schemes employing phase and amplitude-modulated dual band - selective 180° Pulses as basic “ R ” element and tailoring of the Rf field-modulation profile of the 180° Pulses so as to obtain efficient magnetisation transfer characteristics over the resonance offset range of the nuclei involved. Mixing schemes leading to simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling would permit the one-shot acquisition of different chemical shift correlation spectra that are typically utilized for protein backbone resonance assignments and thereby save data acquisition time. At representative MAS frequencies the efficacies of the mixing schemes presented here have been experimentally demonstrated via the simultaneous acquisition of {3D CONH and 3D CANH}, {3D CONH and 3D CO(CA)NH} and {3D CONH, 3D CANH, 3D CO(CA)NH and 3D CA(CO)NH} spectra generated via the magnetisation transfer pathways ^1H → ^13CO → ^15N → ^1H (CONH), ^1H → ^13CA → ^15N → ^1H (CANH) and ^1H → ^13CO → ^13CA → ^15N → ^1H (CO(CA)NH) and ^1H → ^13CA → ^13CO → ^15N → ^1H (CA(CO)NH).
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mas solid state nmr of proteins simultaneous 15n 13ca and 15n 13co dipolar recoupling via low power symmetry based Rf Pulse schemes
Journal of Biomolecular NMR, 2015Co-Authors: Christian Herbst, Matthias Görlach, Peter Bellstedt, Ramadurai RamachandranAbstract:The generation of efficient RN n (ν)s,(ν)k symmetry-based low-power Rf Pulse schemes for simultaneous (15)N-(13)CA and (15)N-(13)CO dipolar recoupling is demonstrated. The method involves mixing schemes employing phase and amplitude-modulated dual band-selective 180° Pulses as basic "R" element and tailoring of the Rf field-modulation profile of the 180° Pulses so as to obtain efficient magnetisation transfer characteristics over the resonance offset range of the nuclei involved. Mixing schemes leading to simultaneous (15)N-(13)CA and (15)N-(13)CO dipolar recoupling would permit the one-shot acquisition of different chemical shift correlation spectra that are typically utilized for protein backbone resonance assignments and thereby save data acquisition time. At representative MAS frequencies the efficacies of the mixing schemes presented here have been experimentally demonstrated via the simultaneous acquisition of {3D CONH and 3D CANH}, {3D CONH and 3D CO(CA)NH} and {3D CONH, 3D CANH, 3D CO(CA)NH and 3D CA(CO)NH} spectra generated via the magnetisation transfer pathways (1)H → (13)CO → (15)N → (1)H (CONH), (1)H → (13)CA → (15)N → (1)H (CANH) and (1)H → (13)CO → (13)CA → (15)N → (1)H (CO(CA)NH) and (1)H → (13)CA → (13)CO → (15)N → (1)H (CA(CO)NH).
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Broadband ^15N–^13C dipolar recoupling via symmetry-based Rf Pulse schemes at high MAS frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient $$ {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} $$ symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband ^15N–^13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “ R ” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “ R ” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and ^15N–^13C chemical shift correlation experiments. Employing such ^13C–^15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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broadband 15n 13c dipolar recoupling via symmetry based Rf Pulse schemes at high mas frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient \( {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} \) symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband 15N–13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “R” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “R” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and 15N–13C chemical shift correlation experiments. Employing such 13C–15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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Recoupling and decoupling of nuclear spin interactions at high MAS frequencies: numerical design of CN _ n ^ν symmetry-based Rf Pulse schemes
Journal of Biomolecular NMR, 2009Co-Authors: Christian Herbst, Jirada Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Anika Kirschstein, Ramadurai RamachandranAbstract:The CN _ n ^ν class of Rf Pulse schemes, commonly employed for recoupling and decoupling of nuclear spin interactions in magic angle spinning solid state NMR studies of biological systems, involves the application of a basic “ C ” element corresponding to an Rf cycle with unity propagator. In this study, the design of CN _ n ^ν symmetry-based Rf Pulse sequences for achieving ^13C–^13C double-quantum dipolar recoupling and through bond scalar coupling mediated ^13C–^13C chemical shift correlation has been examined at high MAS frequencies employing broadband, constant-amplitude, phase-modulated basic “ C ” elements. The basic elements were implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by an Rf phase value. The phase-modulation profile of the “ C ” element was optimised numerically so as to generate efficient Rf Pulse sequences. The peRformances of the sequences were evaluated via numerical simulations and experimental measurements and are presented here.
Matthias Görlach - One of the best experts on this subject based on the ideXlab platform.
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MAS solid state NMR of proteins: simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling via low-power symmetry-based Rf Pulse schemes
Journal of Biomolecular NMR, 2015Co-Authors: Christian Herbst, Matthias Görlach, Peter Bellstedt, Ramadurai RamachandranAbstract:The generation of efficient RN_ n ^νs,^νk symmetry-based low-power Rf Pulse schemes for simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling is demonstrated. The method involves mixing schemes employing phase and amplitude-modulated dual band - selective 180° Pulses as basic “ R ” element and tailoring of the Rf field-modulation profile of the 180° Pulses so as to obtain efficient magnetisation transfer characteristics over the resonance offset range of the nuclei involved. Mixing schemes leading to simultaneous ^15N–^13CA and ^15N–^13CO dipolar recoupling would permit the one-shot acquisition of different chemical shift correlation spectra that are typically utilized for protein backbone resonance assignments and thereby save data acquisition time. At representative MAS frequencies the efficacies of the mixing schemes presented here have been experimentally demonstrated via the simultaneous acquisition of {3D CONH and 3D CANH}, {3D CONH and 3D CO(CA)NH} and {3D CONH, 3D CANH, 3D CO(CA)NH and 3D CA(CO)NH} spectra generated via the magnetisation transfer pathways ^1H → ^13CO → ^15N → ^1H (CONH), ^1H → ^13CA → ^15N → ^1H (CANH) and ^1H → ^13CO → ^13CA → ^15N → ^1H (CO(CA)NH) and ^1H → ^13CA → ^13CO → ^15N → ^1H (CA(CO)NH).
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mas solid state nmr of proteins simultaneous 15n 13ca and 15n 13co dipolar recoupling via low power symmetry based Rf Pulse schemes
Journal of Biomolecular NMR, 2015Co-Authors: Christian Herbst, Matthias Görlach, Peter Bellstedt, Ramadurai RamachandranAbstract:The generation of efficient RN n (ν)s,(ν)k symmetry-based low-power Rf Pulse schemes for simultaneous (15)N-(13)CA and (15)N-(13)CO dipolar recoupling is demonstrated. The method involves mixing schemes employing phase and amplitude-modulated dual band-selective 180° Pulses as basic "R" element and tailoring of the Rf field-modulation profile of the 180° Pulses so as to obtain efficient magnetisation transfer characteristics over the resonance offset range of the nuclei involved. Mixing schemes leading to simultaneous (15)N-(13)CA and (15)N-(13)CO dipolar recoupling would permit the one-shot acquisition of different chemical shift correlation spectra that are typically utilized for protein backbone resonance assignments and thereby save data acquisition time. At representative MAS frequencies the efficacies of the mixing schemes presented here have been experimentally demonstrated via the simultaneous acquisition of {3D CONH and 3D CANH}, {3D CONH and 3D CO(CA)NH} and {3D CONH, 3D CANH, 3D CO(CA)NH and 3D CA(CO)NH} spectra generated via the magnetisation transfer pathways (1)H → (13)CO → (15)N → (1)H (CONH), (1)H → (13)CA → (15)N → (1)H (CANH) and (1)H → (13)CO → (13)CA → (15)N → (1)H (CO(CA)NH) and (1)H → (13)CA → (13)CO → (15)N → (1)H (CA(CO)NH).
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Broadband ^15N–^13C dipolar recoupling via symmetry-based Rf Pulse schemes at high MAS frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient $$ {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} $$ symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband ^15N–^13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “ R ” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “ R ” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and ^15N–^13C chemical shift correlation experiments. Employing such ^13C–^15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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broadband 15n 13c dipolar recoupling via symmetry based Rf Pulse schemes at high mas frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient \( {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} \) symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband 15N–13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “R” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “R” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and 15N–13C chemical shift correlation experiments. Employing such 13C–15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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Recoupling and decoupling of nuclear spin interactions at high MAS frequencies: numerical design of CN _ n ^ν symmetry-based Rf Pulse schemes
Journal of Biomolecular NMR, 2009Co-Authors: Christian Herbst, Jirada Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Anika Kirschstein, Ramadurai RamachandranAbstract:The CN _ n ^ν class of Rf Pulse schemes, commonly employed for recoupling and decoupling of nuclear spin interactions in magic angle spinning solid state NMR studies of biological systems, involves the application of a basic “ C ” element corresponding to an Rf cycle with unity propagator. In this study, the design of CN _ n ^ν symmetry-based Rf Pulse sequences for achieving ^13C–^13C double-quantum dipolar recoupling and through bond scalar coupling mediated ^13C–^13C chemical shift correlation has been examined at high MAS frequencies employing broadband, constant-amplitude, phase-modulated basic “ C ” elements. The basic elements were implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by an Rf phase value. The phase-modulation profile of the “ C ” element was optimised numerically so as to generate efficient Rf Pulse sequences. The peRformances of the sequences were evaluated via numerical simulations and experimental measurements and are presented here.
Jörg Leppert - One of the best experts on this subject based on the ideXlab platform.
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Broadband ^15N–^13C dipolar recoupling via symmetry-based Rf Pulse schemes at high MAS frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient $$ {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} $$ symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband ^15N–^13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “ R ” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “ R ” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and ^15N–^13C chemical shift correlation experiments. Employing such ^13C–^15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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broadband 15n 13c dipolar recoupling via symmetry based Rf Pulse schemes at high mas frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient \( {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} \) symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband 15N–13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “R” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “R” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and 15N–13C chemical shift correlation experiments. Employing such 13C–15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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Recoupling and decoupling of nuclear spin interactions at high MAS frequencies: numerical design of CN _ n ^ν symmetry-based Rf Pulse schemes
Journal of Biomolecular NMR, 2009Co-Authors: Christian Herbst, Jirada Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Anika Kirschstein, Ramadurai RamachandranAbstract:The CN _ n ^ν class of Rf Pulse schemes, commonly employed for recoupling and decoupling of nuclear spin interactions in magic angle spinning solid state NMR studies of biological systems, involves the application of a basic “ C ” element corresponding to an Rf cycle with unity propagator. In this study, the design of CN _ n ^ν symmetry-based Rf Pulse sequences for achieving ^13C–^13C double-quantum dipolar recoupling and through bond scalar coupling mediated ^13C–^13C chemical shift correlation has been examined at high MAS frequencies employing broadband, constant-amplitude, phase-modulated basic “ C ” elements. The basic elements were implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by an Rf phase value. The phase-modulation profile of the “ C ” element was optimised numerically so as to generate efficient Rf Pulse sequences. The peRformances of the sequences were evaluated via numerical simulations and experimental measurements and are presented here.
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Numerical design of RN _ n ^ν symmetry-based Rf Pulse schemes for recoupling and decoupling of nuclear spin interactions at high MAS frequencies
Journal of Biomolecular NMR, 2009Co-Authors: Christian Herbst, Jirada Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for the efficient implementation of RN _ n ^ν symmetry-based Pulse schemes that are often employed for recoupling and decoupling of nuclear spin interactions in biological solid state NMR investigations is demonstrated at high magic-angle spinning frequencies. Rf Pulse sequences belonging to the RN _ n ^ν symmetry involve the repeated application of the Pulse sandwich { R _ϕ R _−ϕ}, corresponding to a propagator U _Rf = exp(−i4ϕ I _z), where ϕ = πν/ N and R is typically a Pulse that rotates the nuclear spins through 180° about the x -axis . In this study, broadband, phase-modulated 180° Pulses of constant amplitude were employed as the initial ‘ R ’ element and the phase-modulation profile of this ‘ R ’ element was numerically optimised for generating RN _ n ^ν symmetry-based Pulse schemes with satisfactory magnetisation transfer characteristics. At representative MAS frequencies, Rf Pulse sequences were implemented for achieving ^13C–^13C double-quantum dipolar recoupling and through bond scalar coupling mediated chemical shift correlation and evaluated via numerical simulations and experimental measurements. The results from these investigations are presented here.
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Broadband homonuclear chemical shift correlation at high MAS frequencies: a study of tanh/tan adiabatic Rf Pulse schemes without $${^{{\bf 1}}\hbox{{\bf H}}}$$ decou
Journal of Biomolecular NMR, 2007Co-Authors: Kerstin Riedel, Christian Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:At high magic angle spinning (MAS) frequencies the potential of tanh/tan adiabatic Rf Pulse schemes for ^13C chemical shift correlation without ^1H decoupling during mixing has been evaluated. It is shown via numerical simulations that a continuous train of adiabatic ^13C inversion Pulses applied at high Rf field strengths leads to efficient broadband heteronuclear decoupling. It is demonstrated that this can be exploited effectively for generating through-bond and through-space, including double-quantum, correlation spectra of biological systems at high magnetic fields and spinning speeds with no ^1H decoupling applied during the mixing period. Experiments carried out on a polycrystalline sample of histidine clearly suggest that an improved signal to noise ratio can be realised by eliminating ^1H decoupling during mixing.
Oliver Ohlenschläger - One of the best experts on this subject based on the ideXlab platform.
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Broadband ^15N–^13C dipolar recoupling via symmetry-based Rf Pulse schemes at high MAS frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient $$ {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} $$ symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband ^15N–^13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “ R ” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “ R ” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and ^15N–^13C chemical shift correlation experiments. Employing such ^13C–^15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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broadband 15n 13c dipolar recoupling via symmetry based Rf Pulse schemes at high mas frequencies
Journal of Biomolecular NMR, 2010Co-Authors: Christian Herbst, Jirada Herbst, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for generating efficient \( {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} \) symmetry-based dual channel Rf Pulse schemes for γ-encoded broadband 15N–13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation of the Rf phase-modulation profile of the basic “R” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer characteristics. The basic “R” element was implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by a Rf phase and amplitude values. The peRformance characteristics of the sequences were evaluated via numerical simulations and 15N–13C chemical shift correlation experiments. Employing such 13C–15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers, the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated.
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Recoupling and decoupling of nuclear spin interactions at high MAS frequencies: numerical design of CN _ n ^ν symmetry-based Rf Pulse schemes
Journal of Biomolecular NMR, 2009Co-Authors: Christian Herbst, Jirada Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Anika Kirschstein, Ramadurai RamachandranAbstract:The CN _ n ^ν class of Rf Pulse schemes, commonly employed for recoupling and decoupling of nuclear spin interactions in magic angle spinning solid state NMR studies of biological systems, involves the application of a basic “ C ” element corresponding to an Rf cycle with unity propagator. In this study, the design of CN _ n ^ν symmetry-based Rf Pulse sequences for achieving ^13C–^13C double-quantum dipolar recoupling and through bond scalar coupling mediated ^13C–^13C chemical shift correlation has been examined at high MAS frequencies employing broadband, constant-amplitude, phase-modulated basic “ C ” elements. The basic elements were implemented as a sandwich of a small number of short Pulses of equal duration with each Pulse characterised by an Rf phase value. The phase-modulation profile of the “ C ” element was optimised numerically so as to generate efficient Rf Pulse sequences. The peRformances of the sequences were evaluated via numerical simulations and experimental measurements and are presented here.
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Numerical design of RN _ n ^ν symmetry-based Rf Pulse schemes for recoupling and decoupling of nuclear spin interactions at high MAS frequencies
Journal of Biomolecular NMR, 2009Co-Authors: Christian Herbst, Jirada Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:An approach for the efficient implementation of RN _ n ^ν symmetry-based Pulse schemes that are often employed for recoupling and decoupling of nuclear spin interactions in biological solid state NMR investigations is demonstrated at high magic-angle spinning frequencies. Rf Pulse sequences belonging to the RN _ n ^ν symmetry involve the repeated application of the Pulse sandwich { R _ϕ R _−ϕ}, corresponding to a propagator U _Rf = exp(−i4ϕ I _z), where ϕ = πν/ N and R is typically a Pulse that rotates the nuclear spins through 180° about the x -axis . In this study, broadband, phase-modulated 180° Pulses of constant amplitude were employed as the initial ‘ R ’ element and the phase-modulation profile of this ‘ R ’ element was numerically optimised for generating RN _ n ^ν symmetry-based Pulse schemes with satisfactory magnetisation transfer characteristics. At representative MAS frequencies, Rf Pulse sequences were implemented for achieving ^13C–^13C double-quantum dipolar recoupling and through bond scalar coupling mediated chemical shift correlation and evaluated via numerical simulations and experimental measurements. The results from these investigations are presented here.
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Broadband homonuclear chemical shift correlation at high MAS frequencies: a study of tanh/tan adiabatic Rf Pulse schemes without $${^{{\bf 1}}\hbox{{\bf H}}}$$ decou
Journal of Biomolecular NMR, 2007Co-Authors: Kerstin Riedel, Christian Herbst, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach, Ramadurai RamachandranAbstract:At high magic angle spinning (MAS) frequencies the potential of tanh/tan adiabatic Rf Pulse schemes for ^13C chemical shift correlation without ^1H decoupling during mixing has been evaluated. It is shown via numerical simulations that a continuous train of adiabatic ^13C inversion Pulses applied at high Rf field strengths leads to efficient broadband heteronuclear decoupling. It is demonstrated that this can be exploited effectively for generating through-bond and through-space, including double-quantum, correlation spectra of biological systems at high magnetic fields and spinning speeds with no ^1H decoupling applied during the mixing period. Experiments carried out on a polycrystalline sample of histidine clearly suggest that an improved signal to noise ratio can be realised by eliminating ^1H decoupling during mixing.
