Publication year: 2011 Source: Journal of Magnetic Resonance, In Press, Accepted Manuscript, Available online 20 July 2011
Aanatoly K., Khitrin , Jiadi, Xu , Ayyalusamy, Ramamoorthy
Correlation of chemical shifts of low-? nuclei (such as 15N) is an important method for assignment of resonances in uniformly-labeled biological solids. Under static experimental conditions, an efficient mixing of low-? nuclear spin magnetization can be achieved by a thermal contact to the common reservoir of dipole-dipole interactions in order to create 15N-15N, 13C-13C, or 15N-13C cross-peaks in a 2D correlation spectrum. A thermodynamic approach can be used to understand the mechanism of magnetization mixing in various 2D correlation pulse sequences. This mechanism is suppressed under magic-angle spinning, when mixing via direct cross-polarization with protons becomes more efficient. Experimental results... Graphical abstract
*Graphical abstract:**Highlights:*? Efficient 2D 15N chemical shift correlation in polypeptides is demonstrated. ? Efficiency of building cross-peaks decreases with spin dilution. ? The CRDSD technique is well suited for uniformly labeled systems. ? The dipolar bath disappears unde‘r MAS but CP remains the main mixing mechanism.
Rapid Solid-State NMR of Deuterated Proteins by Interleaved Cross-Polarization fromH andH Nuclei
Rapid Solid-State NMR of Deuterated Proteins by Interleaved Cross-Polarization fromH andH Nuclei
Publication year: 2011
Source: Journal of Magnetic Resonance, Available online 9 November 2011</br>
Morten*Bjerring, Berit*Paaske, Hartmut*Oschkinat, Umit*Akbey, Niels Chr.*Nielsen</br>
We present a novel sampling strategy, interleaving acquisition of multiple NMR spectra by exploiting initial polarization subsequently fromH andH spins, taking advantage of their differentT1relaxation times. DifferentH- andH-polarization based spectra are in this way simultaneously recorded improving either...
Ergodicity and efficiency of cross-polarization in NMR of static solids.
Ergodicity and efficiency of cross-polarization in NMR of static solids.
Ergodicity and efficiency of cross-polarization in NMR of static solids.
J Magn Reson. 2011 Apr;209(2):161-6
Authors: Nevzorov AA
Cross-polarization transfer is employed in virtually every solid-state NMR experiment to enhance magnetization of low-gamma spins. Theory and experiment is used to assess the magnitude of the final quasistationary magnetization amplitude. The many-body density matrix equation is solved for relatively large (up to N=14) spin systems without the...
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07-23-2011 08:54 AM
Repetitive cross-polarization contacts via equilibration-re-equilibration of the proton bath: sensitivity enhancement for NMR of membrane proteins reconstituted in magnetically aligned bicelles
Repetitive cross-polarization contacts via equilibration-re-equilibration of the proton bath: sensitivity enhancement for NMR of membrane proteins reconstituted in magnetically aligned bicelles
Publication year: 2011
Source: Journal of Magnetic Resonance, In Press, Accepted Manuscript, Available online 2 July 2011</br>
Wenxing, Tang , Alexander A., Nevzorov</br>
Thermodynamic limit of magnetization corresponding to the intact proton bath often cannot be transferred in a single cross-polarization contact. This is mainly due to the finite ratio between the number densities of the high-...
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07-05-2011 05:52 AM
How uniform is the peptide plane geometry? A high-accuracy NMR study of dipolar Cαâ??Câ?²/HNâ??N cross-correlated relaxation
How uniform is the peptide plane geometry? A high-accuracy NMR study of dipolar Cαâ??Câ?²/HNâ??N cross-correlated relaxation
Abstract Highly precise and accurate measurements of very small NMR cross-correlated relaxation rates, namely those between protein HiNâ??Ni and Ciâ??1αâ??Ciâ??1â?² dipoles, are demonstrated with an error of 0.03 sâ??1 for GB3. Because the projection angles between the two dipole vectors are very close to the magic angle the rates range only from â??0.2 to +0.2 sâ??1. Small changes of the average vector orientations have a dramatic impact on the relative values....
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06-06-2011 12:53 AM
How uniform is the peptide plane geometry? A high-accuracy NMR study of dipolar C(?)-C'/H (N)-N cross-correlated relaxation.
How uniform is the peptide plane geometry? A high-accuracy NMR study of dipolar C(?)-C'/H (N)-N cross-correlated relaxation.
How uniform is the peptide plane geometry? A high-accuracy NMR study of dipolar C(?)-C'/H (N)-N cross-correlated relaxation.
J Biomol NMR. 2011 Jun 3;
Authors: Vögeli B
Highly precise and accurate measurements of very small NMR cross-correlated relaxation rates, namely those between protein H (i) (N) -N(i) and C (i-1) (?) -C(i-1)' dipoles, are demonstrated with an error of 0.03*s(-1) for GB3. Because the projection angles...
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06-04-2011 11:26 AM
Characterization of slow conformational dynamics in solids: dipolar CODEX
Characterization of slow conformational dynamics in solids: dipolar CODEX
Abstract A solid state NMR experiment is introduced for probing relatively slow conformational exchange, based on dephasing and refocusing dipolar couplings. The method is closely related to the previously described Centerband-Only Detection of Exchange or CODEX experiment. The use of dipolar couplings for this application is advantageous because their values are known a priori from molecular structures, and their orientations and reorientations relate in a simple way to molecular geometry and motion. Furthermore...
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01-09-2011 12:46 PM
Nitrogen-14 NMR Spectroscopy Using Residual Dipolar Splittings in Solids
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Nitrogen-14 NMR Spectroscopy Using Residual Dipolar Splittings in Solids
Simone Cavadini, Adonis Lupulescu, Sasa Antonijevic,* and Geoffrey Bodenhausen
Laboratoire de Résonance Magnétique Biomoléculaire, Ecole Polytechnique Fédérale de Lausanne, Batochime, CH-1015 Lausanne, Switzerland, and Département de Chimie, associé au CNRS, Ecole Normale Supérieure, 24 rue Lhomond 75231, Paris Cedex 05, France
J. Am. Chem. Soc., 128 (24), 7706 -7707, 2006.
Cross-Correlations Between Low-? Nuclei in Solids Via a Common Dipolar Bath
Linear Mode
