Dynamic nuclear polarization (DNP) of 15 N 2 O , known for its long-lived singlet-state order at low magnetic field, is demonstrated in organic solvent/trityl mixtures at ~1.5 K and 5 T. Both 15 N polarization and intermolecular dipolar broadening are strongly affected by the sample’s thermal history, indicating spontaneous formation of N2O clusters. In situ 15 N NMR reveals four distinct powder-pattern spectra, attributed to the chemical-shift anisotropy (CSA) tensors of the two 15N nuclei, further split by the intramolecular dipolar coupling between their magnetic moments. 15 N polarization is estimated by fitting the free-induction decay (FID) signals to the analytical model of four single-quantum transitions. This analysis implies ( 10.2 ± 2.2 ) % polarization after 37 h of DNP, and provides a direct, instantaneous probe of the absolute 15 N polarization, without a need for time-consuming referencing to a thermal-equilibrium NMR signal.
[NMR paper] Determining the depth of insertion of dynamically invisible membrane peptides by gel-phase (1)H spin diffusion heteronuclear correlation NMR.
Determining the depth of insertion of dynamically invisible membrane peptides by gel-phase (1)H spin diffusion heteronuclear correlation NMR.
Related Articles Determining the depth of insertion of dynamically invisible membrane peptides by gel-phase (1)H spin diffusion heteronuclear correlation NMR.
J Biomol NMR. 2013 Apr 20;
Authors: Wang T, Yao H, Hong M
Abstract
Solid-state NMR determination of the depth of insertion of membrane peptides and proteins has so far utilized (1)H spin diffusion and paramagnetic relaxation enhancement...
nmrlearner
Journal club
0
04-23-2013 08:37 PM
[NMR paper] Solid-State NMR-Based Approaches for Supramolecular Structure Elucidation.
Solid-State NMR-Based Approaches for Supramolecular Structure Elucidation.
Related Articles Solid-State NMR-Based Approaches for Supramolecular Structure Elucidation.
Acc Chem Res. 2013 Apr 15;
Authors: Weingarth M, Baldus M
Abstract
Supramolecular chemistry provides structural and conformational information about complexes formed from multiple molecules. While the molecule is held together by strong intramolecular contacts like covalent bonds, supramolecular structures can be further stabilized by weaker or transient intermolecular...
nmrlearner
Journal club
0
04-17-2013 08:15 PM
[NMR paper] Computer-Aided Design of Fragment Mixtures for NMR-Based Screening.
Computer-Aided Design of Fragment Mixtures for NMR-Based Screening.
Related Articles Computer-Aided Design of Fragment Mixtures for NMR-Based Screening.
PLoS One. 2013;8(3):e58571
Authors: Arroyo X, Goldflam M, Feliz M, Belda I, Giralt E
Abstract
Fragment-based drug discovery is widely applied both in industrial and in academic screening programs. Several screening techniques rely on NMR to detect binding of a fragment to a target. NMR-based methods are among the most sensitive techniques and have the further advantage of yielding a low...
nmrlearner
Journal club
0
03-22-2013 06:10 PM
Solid state NMR of proteins at high MAS frequencies: symmetry-based mixing and simultaneous acquisition of chemical shift correlation spectra
Solid state NMR of proteins at high MAS frequencies: symmetry-based mixing and simultaneous acquisition of chemical shift correlation spectra
Abstract We have carried out chemical shift correlation experiments with symmetry-based mixing sequences at high MAS frequencies and examined different strategies to simultaneously acquire 3D correlation spectra that are commonly required in the structural studies of proteins. The potential of numerically optimised symmetry-based mixing sequences and the simultaneous recording of chemical shift correlation spectra such as: 3D NCAC and 3D NHH...
nmrlearner
Journal club
0
11-29-2012 03:14 AM
Dynamically committed, uncommitted, and quenched states encoded in protein kinase A revealed by NMR spectroscopy.
Dynamically committed, uncommitted, and quenched states encoded in protein kinase A revealed by NMR spectroscopy.
Dynamically committed, uncommitted, and quenched states encoded in protein kinase A revealed by NMR spectroscopy.
Proc Natl Acad Sci U S A. 2011 Apr 6;
Authors: Masterson LR, Shi L, Metcalfe E, Gao J, Taylor SS, Veglia G
Protein kinase A (PKA) is a ubiquitous phosphoryl transferase that mediates hundreds of cell signaling events. During turnover, its catalytic subunit (PKA-C) interconverts between three major conformational states...
Lineshape-based polarimetry of dynamically-polarized in solid-state mixtures
Linear Mode
