Amorphous selenium, owing to its tremendous technological importance and perhaps to its chemical simplicity, has been studied for nearly a century and yet an unequivocal structural description of this material remains lacking in the literature to date. The primary controversy regarding the structure of a-Se relates to the relative fraction of Se atoms residing in infinite (Se) chains vs. in Se8 rings. Here we present the results of a two-dimensional solid-state 77Se nuclear magnetic resonance (NMR) spectroscopic study of the chain and ring crystalline allotropes of Se as well as of amorphous Se to unequivocally demonstrate that (i) the Se8 rings and the infinite (Se) chains are characterized by their unique 77Se NMR signatures and (ii) the structure of amorphous Se consists exclusively of infinite (Se) chains.
[NMR paper] SEAL by NMR: Glyco-Based Selenium-Labeled Affinity Ligands Detected by NMR Spectroscopy.
SEAL by NMR: Glyco-Based Selenium-Labeled Affinity Ligands Detected by NMR Spectroscopy.
Related Articles SEAL by NMR: Glyco-Based Selenium-Labeled Affinity Ligands Detected by NMR Spectroscopy.
Chemistry. 2014 Sep 5;
Authors: Hamark C, Landström J, Widmalm G
Abstract
We report a method for the screening of interactions between proteins and selenium-labeled carbohydrate ligands. SEAL by NMR is demonstrated with selenoglycosides binding to lectins where the selenium nucleus serves as an NMR-active handle and reports on binding...
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Zeolite Structure Directionby Simple Bis(methylimidazolium)Cations: The Effect of the Spacer Length on Structure Direction andof the Imidazolium Ring Orientation on the 19F NMR Resonances
Zeolite Structure Directionby Simple Bis(methylimidazolium)Cations: The Effect of the Spacer Length on Structure Direction andof the Imidazolium Ring Orientation on the 19F NMR Resonances
Alex Rojas, Luis Gomez-Hortiguela and Miguel A. Camblor
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja210703y/aop/images/medium/ja-2011-10703y_0011.gif
Journal of the American Chemical Society
DOI: 10.1021/ja210703y
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA
http://feeds.feedburner.com/~r/acs/jacsat/~4/iCRALKKrMXw
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[NMR paper] Ring current effects in the active site of medium-chain Acyl-CoA dehydrogenase reveal
Ring current effects in the active site of medium-chain Acyl-CoA dehydrogenase revealed by NMR spectroscopy.
Related Articles Ring current effects in the active site of medium-chain Acyl-CoA dehydrogenase revealed by NMR spectroscopy.
J Am Chem Soc. 2005 Jun 15;127(23):8424-32
Authors: Wu J, Bell AF, Jaye AA, Tonge PJ
Medium-chain acyl-CoA dehydrogenase (MCAD) catalyzes the flavin-dependent oxidation of fatty acyl-CoAs to the corresponding trans-2-enoyl-CoAs. The interaction of hexadienoyl-CoA (HD-CoA), a product analogue, with recombinant pig...
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11-25-2010 08:21 PM
[NMR paper] High precision NMR structure and function of the RING-H2 finger domain of EL5, a rice
High precision NMR structure and function of the RING-H2 finger domain of EL5, a rice protein whose expression is increased upon exposure to pathogen-derived oligosaccharides.
Related Articles High precision NMR structure and function of the RING-H2 finger domain of EL5, a rice protein whose expression is increased upon exposure to pathogen-derived oligosaccharides.
J Biol Chem. 2003 Apr 25;278(17):15341-8
Authors: Katoh S, Hong C, Tsunoda Y, Murata K, Takai R, Minami E, Yamazaki T, Katoh E
EL5, a RING-H2 finger protein, is rapidly induced by...
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[NMR paper] Solution structure of the B-chain of insulin as determined by 1H NMR spectroscopy. Co
Solution structure of the B-chain of insulin as determined by 1H NMR spectroscopy. Comparison with the crystal structure of the insulin hexamer and with the solution structure of the insulin monomer.
Related Articles Solution structure of the B-chain of insulin as determined by 1H NMR spectroscopy. Comparison with the crystal structure of the insulin hexamer and with the solution structure of the insulin monomer.
Int J Pept Protein Res. 1995 Nov;46(5):424-33
Authors: Hawkins B, Cross K, Craik D
The solution structure of the isolated B-chain of...
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[NMR paper] Structure determination of the cyclohexene ring of retinal in bacteriorhodopsin by so
Structure determination of the cyclohexene ring of retinal in bacteriorhodopsin by solid-state deuterium NMR.
Related Articles Structure determination of the cyclohexene ring of retinal in bacteriorhodopsin by solid-state deuterium NMR.
Biochemistry. 1992 Oct 27;31(42):10390-9
Authors: Ulrich AS, Heyn MP, Watts A
The orientation and conformation of retinal within bacteriorhodopsin of the purple membrane of Halobacterium halobium was established by solid-state deuterium NMR spectroscopy, through the determination of individual chemical bond...
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08-21-2010 11:45 PM
[NMR paper] 77Se NMR characterization of 77Se-labeled ovine erythrocyte glutathione peroxidase.
77Se NMR characterization of 77Se-labeled ovine erythrocyte glutathione peroxidase.
Related Articles 77Se NMR characterization of 77Se-labeled ovine erythrocyte glutathione peroxidase.
J Biol Chem. 1991 Mar 15;266(8):4804-9
Authors: Gettins P, Crews BC
Lambs, maintained on a selenium-deficient diet supplemented with 94 atom % Na2 27SeO3, have been used as a source of 77Se-enriched erythrocyte glutathione peroxidase. After 5 months on this diet, the percentage of selenium in the enzyme derived from the supplement had reached 88%. From each...
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Structure analysis of membrane-reconstituted subunit c-ring of E. coli H+-ATP synthas
Abstract The subunit c-ring of H+-ATP synthase (Fo c-ring) plays an essential role in the proton translocation across a membrane driven by the electrochemical potential. To understand its structure and function, we have carried out solid-state NMR analysis under magic-angle sample spinning. The uniformly -labeled Fo c from E. coli (EFo c) was reconstituted into lipid membranes as oligomers. Its high resolution two- and three-dimensional spectra were obtained, and the 13C and 15N signals were assigned. The obtained chemical shifts suggested that EFo c takes on a hairpin-type helix-loop-helix...
Structure of Amorphous Selenium by 2D 77Se NMR Spectroscopy: An End to The Dilemma of Chain vs. Ring
Linear Mode
