A large geometric distortion in the first photointermediate of rhodopsin, determined by double-quantum solid-state NMR
A large geometric distortion in the first photointermediate of rhodopsin, determined by double-quantum solid-state NMR
Abstract Double-quantum magic-angle-spinning NMR experiments were performed on 11,12-13C2-retinylidene-rhodopsin under illumination at low temperature, in order to characterize torsional angle changes at the C11-C12 photoisomerization site. The sample was illuminated in the NMR rotor at low temperature (~120 K) in order to trap the primary photointermediate, bathorhodopsin. The NMR data are consistent with a strong torsional twist of the HCCH moiety at the...
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05-29-2012 01:00 AM
Improved accuracy in measuring one-bond and two-bond 15N,13CĪ± coupling constants in proteins by double-inphase/antiphase (DIPAP) spectroscopy
Improved accuracy in measuring one-bond and two-bond 15N,13CĪ± coupling constants in proteins by double-inphase/antiphase (DIPAP) spectroscopy
Abstract An extension to HN(CO-Ī±/Ī²-N,CĪ±-J)-TROSY (Permi and Annila in J Biomol NMR 16:221ā??227, 2000) is proposed that permits the simultaneous determination of the four coupling constants 1 J Nā?²(i)CĪ±(i), 2 J HN(i)CĪ±(i), 2 J CĪ±(iā??1)Nā?²(i), and 3 J CĪ±(iā??1)HN(i) in 15N,13C-labeled proteins. Contrasting the original scheme, in which two separate subspectra exhibit the 2 J CĪ±Nā?² coupling as inphase and antiphase splitting (IPAP), we...
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06-10-2011 01:41 AM
[U. of Ottawa NMR Facility Blog] Heteronuclear Double Quantum Filters
Heteronuclear Double Quantum Filters
Double quantum filters are used to filter out single quantum magnetization and allow the passage of double quantum magnetization. In the proton observe heteronuclear case, the double quantum filter (like the BIRD filter) allows the selective observation of the weak satellite signals from protons coupled to dilute spin I = 1/2 X nuclei (e.g. X = 13C, 15N, 29Si ....) but rejects the strong singlets from the uncoupled protons in the vicinity of 12C, self decoupled 14N, and 28Si . The figure below illustrates the heteronuclear double quantum filter...
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04-22-2011 03:01 AM
A new method for the determination of free L: -carnitine in serum samples based on high field single quantum coherence filtering (1)H-NMR spectroscopy.
A new method for the determination of free L: -carnitine in serum samples based on high field single quantum coherence filtering (1)H-NMR spectroscopy.
A new method for the determination of free L: -carnitine in serum samples based on high field single quantum coherence filtering (1)H-NMR spectroscopy.
Anal Bioanal Chem. 2011 Jan 11;
Authors: Tsiafoulis CG, Exarchou V, Tziova PP, Bairaktari E, Gerothanassis IP, Troganis AN
The rapid and accurate determination of specific metabolites present in biofluids is a very demanding task which is essential...
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01-12-2011 11:11 AM
[NMR paper] Structural studies of biomaterials using double-quantum solid-state NMR spectroscopy.
Structural studies of biomaterials using double-quantum solid-state NMR spectroscopy.
Related Articles Structural studies of biomaterials using double-quantum solid-state NMR spectroscopy.
Annu Rev Phys Chem. 2003;54:531-71
Authors: Drobny GP, Long JR, Karlsson T, Shaw W, Popham J, Oyler N, Bower P, Stringer J, Gregory D, Mehta M, Stayton PS
Proteins directly control the nucleation and growth of biominerals, but the details of molecular recognition at the protein-biomineral interface remain poorly understood. The elucidation of recognition...
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11-24-2010 08:49 PM
[NMR paper] Solid-state dipolar INADEQUATE NMR spectroscopy with a large double-quantum spectral
Solid-state dipolar INADEQUATE NMR spectroscopy with a large double-quantum spectral width.
Related Articles Solid-state dipolar INADEQUATE NMR spectroscopy with a large double-quantum spectral width.
J Magn Reson. 1999 Jan;136(1):86-91
Authors: Hong M
A technique for obtaining dipolar-mediated INADEQUATE NMR spectra with a large spectral window in the double-quantum dimension is presented. Using the dipolar recoupling sequence C7 to excite the double-quantum coherence under magic-angle spinning, the technique involves incrementing the...
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11-18-2010 07:05 PM
Improved Resolution in Dipolar NMR Spectra Using Constant Time Evolution PISEMA Exper
Improved Resolution in Dipolar NMR Spectra Using Constant Time Evolution PISEMA Experiment.
Related Articles Improved Resolution in Dipolar NMR Spectra Using Constant Time Evolution PISEMA Experiment.
Chem Phys Lett. 2010 Jul 9;494(1-3):104-110
Authors: Gopinath T, Veglia G
The atomic structure of small molecules and polypeptides can be attained from anisotropic NMR parameters such as dipolar couplings (DC) and chemical shifts (CS). Separated local field experiments resolve DC and CS correlations into two dimensions. However, crowded NMR...
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09-05-2010 05:53 AM
Double quantum filtering homonuclear MAS NMR correlation spectra: a tool for membrane protein studies
Double quantum filtering homonuclear MAS NMR correlation spectra: a tool for membrane protein studies
Jakob J. Lopez, Christoph Kaiser, Sarika Shastri and Clemens Glaubitz
Journal of Biomolecular NMR; 2008; 41(2) pp 97 - 104
Abstract:
13C homonuclear correlation spectra based on proton driven spin diffusion (PDSD) are becoming increasingly important for obtaining distance constraints from multiply labeled biomolecules by MAS NMR. One particular challenging situation arises when such constraints are to be obtained from spectra with a large natural abundance signal background which...