High-field ELDOR-detected NMR study of a nitroxide radical in disordered solids:Towards characterization of heterogeneity of microenvironments in spin-labeled systems
High-field ELDOR-detected NMR study of a nitroxide radical in disordered solids:Towards characterization of heterogeneity of microenvironments in spin-labeled systems
Publication date: Available online 12 March 2014 Source:Journal of Magnetic Resonance
Author(s): Anna Nalepa , Klaus Möbius , Wolfgang Lubitz , Anton Savitsky
The combination of high-field EPR with site-directed spin-labeling (SDSL) techniques employing nitroxide radicals has turned out to be particularly powerful in probing the polarity and proticity characteristics of protein/matrix systems. This information is concluded from the principal components of the nitroxide Zeeman (g), nitrogen hyperfine (A) and quadrupole (P) tensors of the spin labels attached to specific sites. Recent multi-frequency high-field EPR studies underlined the complexity of the problem to treat the nitroxide microenvironment in proteins adequately due to inherent heterogeneities which result in several principal x-components of the nitroxide g-tensor. Concomitant, but distinctly different nitrogen hyperfine components could, however, not be determined from high-field cw EPR experiments owing to the large intrinsic EPR linewidth in fully protonated guest/host systems. It is shown in this work that, using the W-band (95GHz) ELDOR- (electron-electron double resonance) detected NMR (EDNMR) method, different principal hyperfine, Azz, and quadrupole, Pzz, tensor values of a nitroxide radical in glassy 2-propanol matrix can be measured with high accuracy. They belong to nitroxides with different hydrogen-bond situations. The satisfactory resolution and superior sensitivity of EDNMR as compared to the standard ENDOR (electron-nuclear double resonance) method are demonstrated. Graphical abstract
High-Field (13)C Dynamic Nuclear Polarization with a Radical Mixture
From the The DNP-NMR Blog:
High-Field (13)C Dynamic Nuclear Polarization with a Radical Mixture
Michaelis, V.K., et al., High-Field (13)C Dynamic Nuclear Polarization with a Radical Mixture. J Am Chem Soc, 2013.
http://www.ncbi.nlm.nih.gov/pubmed/23373472
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04-15-2013 08:52 AM
Computational Study andMolecular Orbital Analysisof NMR Shielding, Spin–Spin Coupling, and Electric Field Gradientsof Azido Platinum Complexes
Computational Study andMolecular Orbital Analysisof NMR Shielding, Spin–Spin Coupling, and Electric Field Gradientsof Azido Platinum Complexes
Kiplangat Sutter and Jochen Autschbach
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja3040762/aop/images/medium/ja-2012-040762_0008.gif
Journal of the American Chemical Society
DOI: 10.1021/ja3040762
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA
http://feeds.feedburner.com/~r/acs/jacsat/~4/XTeiJ4ddvO4
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08-04-2012 05:22 AM
Continuous-wave EPR at 275 GHz: Application to high-spin Fe3+ systems
Continuous-wave EPR at 275 GHz: Application to high-spin Fe3+ systems
Publication year: 2011
Source: Journal of Magnetic Resonance, In Press, Accepted Manuscript, Available online 11 March 2011</br>
G., Mathies , H., Blok , J.A.J.M., Disselhorst , P., Gast , H., van der Meer , ...</br>
The 275 GHz electron-paramagnetic-resonance spectrometer we reported on in 2004 has been equipped with a new probe head, which contains a cavity especially designed for operation in continuous-wave mode. The sensitivity and signal stability that is achieved with this new probe head is illustrated...
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03-12-2011 05:21 PM
Self-diffusion in Polymer Systems studied by Magnetic Field-Gradient Spin-Echo NMR Me
Self-diffusion in Polymer Systems studied by Magnetic Field-Gradient Spin-Echo NMR Methods
Publication year: 2010
Source: Progress in Nuclear Magnetic Resonance Spectroscopy, In Press, Accepted Manuscript, Available online 13 April 2010</br>
Harald, Walderhaug , Olle, Söderman , Daniel, Topgaard</br>
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