Related ArticlesSpectral editing through laser-flash excitation in two-dimensional photo-CIDNP MAS NMR experiments.
J Magn Reson. 2014 Sep;246:9-17
Authors: Sai Sankar Gupta KB, Daviso E, Jeschke G, Alia A, Ernst M, Matysik J
Abstract
In solid-state photochemically induced dynamic nuclear polarization (photo-CIDNP) MAS NMR experiments, strong signal enhancement is observed from molecules forming a spin-correlated radical pair in a rigid matrix. Two-dimensional (13)C-(13)C dipolar-assisted rotational resonance (DARR) photo-CIDNP MAS NMR experiments have been applied to obtain exact chemical shift assignments from those cofactors. Under continuous illumination, the signals are enhanced via three-spin mixing (TSM) and differential decay (DD) and their intensity corresponds to the electron spin density in pz orbitals. In multiple-(13)C labelled samples, spin diffusion leads to propagation of signal enhancement to all (13)C spins. Under steady-state conditions, direct signal assignment is possible due to the uniform signal intensity. The original intensities, however, are inaccessible and the information of the local electron spin density is lost. Upon laser-flash illumination, the signal is enhanced via the classical radical pair mechanism (RPM). The obtained intensities are related to isotropic hyperfine interactions aiso and both enhanced absorptive and emissive lines can be observed due to differences in the sign of the local isotropic hyperfine interaction. Exploiting the mechanism of the polarization, selectivity can be increased by the novel time-resolved two-dimensional dipolar-assisted rotational resonance (DARR) MAS NMR experiment which simplifies the signal assignment compared to complex spectra of the same RCs obtained by continuous illumination. Here we present two-dimensional time-resolved photo-CIDNP MAS NMR experiments providing both directly: signal assignment and spectral editing by sign and strength of aiso. Hence, this experiment provides a direct key to the electronic structure of the correlated radical pair.
Spectral editing through laser-flash excitation in two-dimensional photo-CIDNP MAS NMR experiments
From The DNP-NMR Blog:
Spectral editing through laser-flash excitation in two-dimensional photo-CIDNP MAS NMR experiments
Sai Sankar Gupta, K.B., et al., Spectral editing through laser-flash excitation in two-dimensional photo-CIDNP MAS NMR experiments. J Magn Reson, 2014. 246C(0): p. 9-17.
http://www.ncbi.nlm.nih.gov/pubmed/25063951
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09-18-2014 12:12 AM
Spectral editing through laser-flash excitation in two-dimensional photo-CIDNP MAS NMR experiments
From The DNP-NMR Blog:
Spectral editing through laser-flash excitation in two-dimensional photo-CIDNP MAS NMR experiments
Gupta, K.B.S.S., et al., Spectral editing through laser-flash excitation in two-dimensional photo-CIDNP MAS NMR experiments. J. Magn. Reson., 2014(0).
http://www.sciencedirect.com/science/article/pii/S1090780714001761
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07-02-2014 02:37 PM
Spectral editing of two-dimensional magic-angle-spinning solid-state NMR spectra for protein resonance assignment and structure determination
Spectral editing of two-dimensional magic-angle-spinning solid-state NMR spectra for protein resonance assignment and structure determination
Abstract Several techniques for spectral editing of 2D 13Cā??13C correlation NMR of proteins are introduced. They greatly reduce the spectral overlap for five common amino acid types, thus simplifying spectral assignment and conformational analysis. The carboxyl (COO) signals of glutamate and aspartate are selected by suppressing the overlapping amide Nā??CO peaks through 13Cā??15N dipolar dephasing. The sidechain methine (CH) signals of valine,...
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10-13-2012 04:42 AM
Selective Photochemistry at Stereogenic Metal and Ligand Centers of cis-[Ru(diphosphine)2(H)2]: Preparative, NMR, Solid State, and Laser Flash Studies
Selective Photochemistry at Stereogenic Metal and Ligand Centers of cis-: Preparative, NMR, Solid State, and Laser Flash Studies
Marius V. Campian, Robin N. Perutz, Barbara Procacci, Robert J. Thatcher, Olga Torres and Adrian C. Whitwood
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja210568t/aop/images/medium/ja-2011-10568t_0015.gif
Journal of the American Chemical Society
DOI: 10.1021/ja210568t
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA
http://feeds.feedburner.com/~r/acs/jacsat/~4/CL2cbLequjw
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02-14-2012 03:00 AM
[NMR paper] Photo-CIDNP NMR spectroscopy of a heme-containing protein.
Photo-CIDNP NMR spectroscopy of a heme-containing protein.
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J Magn Reson. 2005 Aug;175(2):330-5
Authors: Day IJ, Wain R, Tozawa K, Smith LJ, Hore PJ
There are relatively few examples of the application of photo-CIDNP NMR spectroscopy to chromophore-containing proteins. The most likely reason for this is that simultaneous absorption of light by the photosensitiser molecule and the protein chromophore reduces the effectiveness of the photochemical reaction that produces...
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12-01-2010 06:56 PM
[NMR paper] Photo-CIDNP NMR methods for studying protein folding.
Photo-CIDNP NMR methods for studying protein folding.
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Methods. 2004 Sep;34(1):75-87
Authors: Mok KH, Hore PJ
Chemically induced dynamic nuclear polarization (CIDNP) is a nuclear magnetic resonance phenomenon that can be used to probe the solvent-accessibility of tryptophan, tyrosine, and histidine residues in proteins by means of laser-induced photochemical reactions, resulting in significant enhancement of NMR signals. CIDNP offers good sensitivity as a surface probe of...
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11-24-2010 10:01 PM
[NMR paper] Carbohydrate-protein interaction studies by laser photo CIDNP NMR methods.
Carbohydrate-protein interaction studies by laser photo CIDNP NMR methods.
Related Articles Carbohydrate-protein interaction studies by laser photo CIDNP NMR methods.
Glycoconj J. 1997 Jun;14(4):531-4
Authors: Siebert HC, Kaptein R, Beintema JJ, Soedjanaatmadja UM, Wright CS, Rice A, Kleineidam RG, Kruse S, Schauer R, Pouwels PJ, Kamerling JP, Gabius HJ, Vliegenthart JF
The side chains of tyrosine, tryptophan and histidine are able to produce CIDNP (Chemically Induced Dynamic Nuclear Polarization) signals after laser irradiation in the...
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08-22-2010 03:31 PM
[NMR paper] Carbohydrate-protein interaction studies by laser photo CIDNP NMR methods.
Carbohydrate-protein interaction studies by laser photo CIDNP NMR methods.
Related Articles Carbohydrate-protein interaction studies by laser photo CIDNP NMR methods.
Glycoconj J. 1997 Jun;14(4):531-4
Authors: Siebert HC, Kaptein R, Beintema JJ, Soedjanaatmadja UM, Wright CS, Rice A, Kleineidam RG, Kruse S, Schauer R, Pouwels PJ, Kamerling JP, Gabius HJ, Vliegenthart JF
The side chains of tyrosine, tryptophan and histidine are able to produce CIDNP (Chemically Induced Dynamic Nuclear Polarization) signals after laser irradiation in the...