A sample of solubilized and quinone-depleted reaction centers from the purple bacterium Rhodobacter (R.) sphaeroides wild type has been prepared entirely (13)C and (15)N isotope labeled at all positions of the protein as well as of the cofactors. In this sample, the occurrence of the solid-state photo-CIDNP (photochemically induced dynamic nuclear polarization) effect has been probed by (13)C solid-state magic-angle spinning NMR under illumination. Under continuous illumination, signal intensities are modified by the three-spin mixing (TSM) mechanism. Time-resolved illumination experiments reveal the occurrence of light-induced nuclear polarization on the time scale of hundreds of microseconds, initially dominated by the transient polarization of the singlet branch of the radical-pair mechanism. A first kinetic analysis shows that the lifetime of the polarization from the singlet branch, indicated by the enhanced absorptive intensities of the signals from aliphatic carbons, is significantly extended. Upon arrival of the polarization from the triplet decay branch, emissive polarization caused by the TSM mechanism is observed. Also, this arrival is significantly delayed. The decay of TSM polarization occurs in two steps, assigned to intra- and intermolecular spin diffusion.
[NMR paper] Structure determination of uniformly (13)C, (15)N labeled protein using qualitative distance restraints from MAS solid-state (13)C-NMR observed paramagnetic relaxation enhancement.
Structure determination of uniformly (13)C, (15)N labeled protein using qualitative distance restraints from MAS solid-state (13)C-NMR observed paramagnetic relaxation enhancement.
Related Articles Structure determination of uniformly (13)C, (15)N labeled protein using qualitative distance restraints from MAS solid-state (13)C-NMR observed paramagnetic relaxation enhancement.
J Biomol NMR. 2016 Jan 4;
Authors: Tamaki H, Egawa A, Kido K, Kameda T, Kamiya M, Kikukawa T, Aizawa T, Fujiwara T, Demura M
Abstract
Magic angle spinning...
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Structure determination of uniformly 13 C, 15 N labeled protein using qualitative distance restraints from MAS solid-state 13 C-NMR observed paramagnetic relaxation enhancement
Structure determination of uniformly 13 C, 15 N labeled protein using qualitative distance restraints from MAS solid-state 13 C-NMR observed paramagnetic relaxation enhancement
Abstract
Magic angle spinning (MAS) solid-state nuclear magnetic resonance (NMR) is a powerful method for structure determination of insoluble biomolecules. However, structure determination by MAS solid-state NMR remains challenging because it is difficult to obtain a sufficient amount of distance restraints owing to spectral complexity. Collection of distance restraints from...
[NMR paper] Photochemically Induced Dynamic Nuclear Polarization Observed by Solid-state NMR in a Uniformly (13)C-isotope Labeled Photosynthetic Reaction Center.
Photochemically Induced Dynamic Nuclear Polarization Observed by Solid-state NMR in a Uniformly (13)C-isotope Labeled Photosynthetic Reaction Center.
Related Articles Photochemically Induced Dynamic Nuclear Polarization Observed by Solid-state NMR in a Uniformly (13)C-isotope Labeled Photosynthetic Reaction Center.
J Phys Chem B. 2015 Jun 25;
Authors: Paul S, Bode BE, Matysik J, Alia A
Abstract
A sample of solubilized and quinone-depleted reaction centers (RC) from the purple bacterium Rhodobacter (R.) sphaeroides wild-type (WT)...
[NMR paper] Detecting a New Source for Photochemically Induced Dynamic Nuclear Polarization in the LOV2 Domain of Phototropin by Magnetic-Field Dependent (13)C-NMR Spectroscopy.
Detecting a New Source for Photochemically Induced Dynamic Nuclear Polarization in the LOV2 Domain of Phototropin by Magnetic-Field Dependent (13)C-NMR Spectroscopy.
Related Articles Detecting a New Source for Photochemically Induced Dynamic Nuclear Polarization in the LOV2 Domain of Phototropin by Magnetic-Field Dependent (13)C-NMR Spectroscopy.
J Phys Chem B. 2014 Sep 10;
Authors: Kothe G, Lukaschek M, Link G, Kacprzak S, Illarionov B, Fischer M, Eisenreich W, Bacher A, Weber S
Abstract
Phototropin is a flavin mononucleotide...
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Symmetry Break of Special Pair: Photochemically Induced Dynamic Nuclear Polarization NMR Confirms Control by Nonaromatic Substituents
Symmetry Break of Special Pair: Photochemically Induced Dynamic Nuclear Polarization NMR Confirms Control by Nonaromatic Substituents
Karthick Babu Sai Sankar Gupta, A. Alia, Huub J.M. de Groot and Jo?rg Matysik
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja402238w/aop/images/medium/ja-2013-02238w_0006.gif
Journal of the American Chemical Society
DOI: 10.1021/ja402238w
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA
http://feeds.feedburner.com/~r/acs/jacsat/~4/SoHEJYzuguk
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[NMR paper] Symmetry break of special pair: Photochemically induced dynamic nuclear polarization NMR confirms control by nonaromatic substituents.
Symmetry break of special pair: Photochemically induced dynamic nuclear polarization NMR confirms control by nonaromatic substituents.
Symmetry break of special pair: Photochemically induced dynamic nuclear polarization NMR confirms control by nonaromatic substituents.
J Am Chem Soc. 2013 Jun 6;
Authors: Sai Sankar Gupta KB, Alia A, de Groot HJ, Matysik J
Abstract
Despite the high structural symmetry of cofactor arrangement and protein environment, light-induced electron transfer in photosynthetic reaction centers (RCs) of the purple...
Photochemically Induced Dynamic Nuclear Polarization Observed by Solid-State NMR in a Uniformly (13)C-Isotope-Labeled Photosynthetic Reaction Center
Linear Mode
