A Two-Dimensional Magic-Angle Decoupling and Magic-Angle Turning Solid-State NMR Method:  An Application to Study Chemical Shift Tensors from Peptides That Are Nonselectively Labeled with15N Isotope

2001 ◽  
Vol 105 (20) ◽  
pp. 4752-4762 ◽  
Author(s):  
Dong-Kuk Lee ◽  
Yufeng Wei ◽  
A. Ramamoorthy
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Solid State Nmr ◽  
Magic Angle ◽  
Two Dimensional ◽  
Chemical Shift Tensors ◽  
Nmr Method

scholarly journals Temperature-Dependent Solid-State NMR Proton Chemical-Shift Values and Hydrogen Bonding

2021 ◽  
Author(s):  
Alexander A. Malär ◽  
Laura A. Völker ◽  
Riccardo Cadalbert ◽  
Lauriane Lecoq ◽  
Matthias Ernst ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Chemical Shift ◽  
Hydrogen Bonds ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Proton Chemical Shift ◽  
Temperature Dependent

Temperature-dependent NMR experiments are often complicated by rather long magnetic-field equilibration times, for example occurring upon a change of sample temperature. We demonstrate that the fast temporal stabilization of the magnetic field can be achieved by actively stabilizing the temperature which allows to quantify the weak temperature dependence of the proton chemical shift which can be diagnostic for the presence of hydrogen bonds. Hydrogen bonding plays a central role in molecular recognition events from both fields, chemistry and biology. Their direct detection by standard structure determination techniques, such as X-ray crystallography or cryo-electron microscopy, remains challenging due to the difficulties of approaching the required resolution, on the order of 1 Å. We herein explore a spectroscopic approach using solid-state NMR to identify protons engaged in hydrogen bonds and explore the measurement of proton chemical-shift temperature coefficients. Using the examples of a phosphorylated amino acid and the protein ubiquitin, we show that fast Magic-Angle Spinning (MAS) experiments at 100 kHz yield sufficient resolution in proton-detected spectra to quantify the rather small chemical-shift changes upon temperature variations.<br>

Probing solid iminobis(diorganophosphine chalcogenide) systems with multinuclear magnetic resonance

2009 ◽  
Vol 87 (1) ◽  
pp. 348-360 ◽  
Author(s):  
Bryan A Demko ◽  
Roderick E Wasylishen
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Solid State Nmr ◽  
Magnetic Shielding ◽  
Chemical Shift Tensors ◽  
X Ray ◽  
X Ray Crystallography ◽  
Shielding Tensor ◽  
Nuclear Magnetic Shielding Tensors ◽  
Nuclear Magnetic

A 31P and 77Se solid-state NMR investigation of the iminobis(diorganophosphine chalcogenide) HN(R2PE)2 (R = Ph,iPr; E = O, S, Se) systems is presented. The NMR results are discussed in terms of the known HN(R2PE)2 structures available from X-ray crystallography. The phosphorus chemical shift tensors are found to be sensitive to the nature of the alkyl and chalcogen substituents. The nature of the R group also influences the selenium chemical shift tensors of HN(R2PSe)2 (R = Ph, iPr), which are shown to be sensitive to hydrogen bonding in the dimer structure of HN(Ph2PSe)2 and to the presence of disorder in the case of HN(iPr2PSe)2. Scalar relativistic ZORA DFT nuclear magnetic shielding tensor calculations were performed yielding the orientations of the corresponding chemical shift tensors. A theoretical investigation into the effect of the E-P···P-E “torsion” angle on the phosphorus and selenium chemical shift tensors of a truncated HN(Me2PSe)2 system indicates that the electronic effect of the alkyl group on the respective nuclear magnetic shielding tensors are more important than the steric effect of the E-P···P-E torsion angle.Key words: iminobis(diorganophosphine chalcogenide), solid-state NMR, 31P NMR, 77Se NMR, ZORA DFT.

Acetylenic Carbon-13 Chemical Shift Tensors for Diphenylacetylene and (η2-Diphenylacetylene)Pt(PPh3)2:  A Solid-State NMR and Theoretical Study

2006 ◽  
Vol 45 (6) ◽  
pp. 2461-2473 ◽  
Author(s):  
Kristopher J. Harris ◽  
Guy M. Bernard ◽  
Chris McDonald ◽  
Robert McDonald ◽  
Michael J. Ferguson ◽  
...  
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Solid State Nmr ◽  
Theoretical Study ◽  
Chemical Shift Tensors

A 13C solid-state NMR investigation of four cocrystals of caffeine and theophylline

2017 ◽  
Vol 73 (3) ◽  
pp. 234-243 ◽  
Author(s):  
Nicolas J. Vigilante ◽  
Manish A. Mehta
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Solid State Nmr ◽  
Chemical Shifts ◽  
Active Pharmaceutical Ingredient ◽  
Magic Angle Spinning ◽  
Chemical Shift Tensor ◽  
Magic Angle ◽  
Isotropic Chemical Shifts ◽  
Angle Spinning

We report an analysis of the 13C solid-state NMR chemical shift data in a series of four cocrystals involving two active pharmaceutical ingredient (API) mimics (caffeine and theophylline) and two diacid coformers (malonic acid and glutaric acid). Within this controlled set, we make comparisons of the isotropic chemical shifts and the principal values of the chemical shift tensor. The dispersion at 14.1 T (600 MHz 1H) shows crystallographic splittings in some of the resonances in the magic angle spinning spectra. By comparing the isotropic chemical shifts of individual C atoms across the four cocrystals, we are able to identify pronounced effects on the local electronic structure at some sites. We perform a similar analysis of the principal values of the chemical shift tensors for the anisotropic C atoms (most of the ring C atoms for the API mimics and the carbonyl C atoms of the diacid coformers) and link them to differences in the known crystal structures. We discuss the future prospects for extending this type of study to incorporate the full chemical shift tensor, including its orientation in the crystal frame of reference.

scholarly journals TmDOTP : An NMR- based Thermometer for Magic Angle Spinning NMR Experiments

2019 ◽  
Author(s):  
Dongyu Zhang ◽  
Boris Itin ◽  
Ann E. McDermott
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Radio Frequency ◽  
Solid State Nmr ◽  
Lanthanide Complex ◽  
Magic Angle Spinning ◽  
Sample Temperature ◽  
Proton Spectrum ◽  
Magic Angle ◽  
Angle Spinning

AbstractSolid state NMR is a powerful tool to probe membrane protein structure and motions in native lipid structures. Sample heating, caused by magic angle spinning and radio frequency irradiation in solid state NMR, produces uncertainties in sample temperature and thermal broadening caused by temperature distributions, which can also lead to sample deterioration. To measure the sample temperature in real time, and to quantify thermal gradients and their dependence on radio frequency irradiation or spinning frequency, we use the chemical shift thermometer TmDOTP, a lanthanide complex. Compared to other NMR thermometers (e.g., the proton NMR signal of water), the proton spectrum of TmDOTP exhibits higher thermal sensitivity and resolution. In addition, the H6 proton in TmDOTP has a large chemical shift (−175 ppm at 275 K) and is well resolved from the rest of the proton spectrum. We identified two populations of TmDOTP, with differing temperatures and dependency on the radio frequency irradiation power, within proteoliposome samples. We interpret these populations as arising from the supernatant and the pellet, which is sedimented from the sample spinning. Our results indicate that TmDOTP is an excellent internal standard for monitoring temperatures of biophysically relevant samples without distorting their properties.

scholarly journals The use of a selective saturation pulse to suppress t 1 noise in two-dimensional 1 H fast magic angle spinning solid-state NMR spectroscopy

2015 ◽  
Vol 260 ◽  
pp. 89-97 ◽  
Author(s):  
Aiden J. Robertson ◽  
Manoj Kumar Pandey ◽  
Andrew Marsh ◽  
Yusuke Nishiyama ◽  
Steven P. Brown
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Two Dimensional ◽  
Saturation Pulse ◽  
Selective Saturation ◽  
Angle Spinning ◽  
Fast Magic Angle Spinning

A 2D MAS solid-state NMR method to recover the amplified heteronuclear dipolar and chemical shift anisotropic interactions

2002 ◽  
Vol 158 (1-2) ◽  
pp. 23-35 ◽  
Author(s):  
Yufeng Wei ◽  
Dong-Kuk Lee ◽  
Ann E McDermott ◽  
A Ramamoorthy
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Solid State Nmr ◽  
Nmr Method ◽  
Anisotropic Interactions
Sign in / Sign up

Export Citation Format

Share Document