Related Articles19F NMR magnetization transfer between 5-FBAPTA and its complexes. An alternative means for measuring free Ca2+ concentration, and detection of complexes with protein in erythrocytes.
NMR Biomed. 1994 Nov;7(7):330-8
Authors: Gilboa H, Chapman BE, Kuchel PW
The 19F NMR Ca(2+)-indicator molecule 5,5'-difluoro-1,2-bis(o- aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (5-FBAPTA) was used in a procedure that enhances its range of applications to measuring free Ca2+ concentrations in buffer solutions and human erythrocytes. Even if the signal from the Ca-5-FBAPTA complex was not visible, the concentration of the complex could be calculated from saturation transfer spectra. This was demonstrated with well characterized buffer solutions in vitro and shown to also apply to concentrated haemolysates. The analysis required a precise estimate of the dissociation rate constant of the complex; this was found to be 295/s at 37 degrees C and the corresponding association rate constant was 4.1 x 10(8) L/mol/s. These values differ from those obtained previously in different buffer conditions and by two different NMR methods. A series of spectra were acquired from haemolysates containing 5-FBAPTA, in which saturating irradiation was applied at a frequency that was progressively off-set from the carrier frequency. Saturation transfer to the free 5-FBAPTA was seen from irradiation at frequencies different from that of Ca-5-FBAPTA, thus suggesting the presence of complexes with proteins.
[MWClarkson blog] Alternative side-chain structures from methyl CPMG
Alternative side-chain structures from methyl CPMG
http://www.researchblogging.org/public/citation_icons/rb2_large_gray.pngAs I have mentioned before on this blog, the use of tools like CS-ROSETTA holds the promise of determining protein structures using only the chemical shifts of its backbone atoms. In addition to potentially making NOEs and RDCs redundant, this technology allows biologists to determine the conformations of minor members of the structural ensemble, which are very difficult to obtain using conventional approaches in population-dominated techniques like NMR and X-ray...
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06-21-2011 03:31 AM
Reaction Pathways of Proton Transfer in Hydrogen-Bonded Phenol–Carboxylate Complexes Explored by Combined UV–Vis and NMR Spectroscopy
Reaction Pathways of Proton Transfer in Hydrogen-Bonded Phenol–Carboxylate Complexes Explored by Combined UV–Vis and NMR Spectroscopy
Benjamin Koeppe, Peter M. Tolstoy and Hans-Heinrich Limbach
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja201113a/aop/images/medium/ja-2011-01113a_0002.gif
Journal of the American Chemical Society
DOI: 10.1021/ja201113a
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA
http://feeds.feedburner.com/~r/acs/jacsat/~4/QUQwn6dGPs4
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05-03-2011 05:18 AM
The interaction of La(3+) complexes of DOTA/DTPA glycoconjugates with the RCA(120) lectin: a saturation transfer difference NMR spectroscopic study.
The interaction of La(3+) complexes of DOTA/DTPA glycoconjugates with the RCA(120) lectin: a saturation transfer difference NMR spectroscopic study.
The interaction of La(3+) complexes of DOTA/DTPA glycoconjugates with the RCA(120) lectin: a saturation transfer difference NMR spectroscopic study.
J Biol Inorg Chem. 2011 Apr 3;
Authors: Teixeira JM, Dias DM, Cańada FJ, Martins JA, André JP, Jiménez-Barbero J, Geraldes CF
The study of ligand-receptor interactions using high-resolution NMR techniques, namely the saturation transfer difference (STD),...
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04-05-2011 10:22 PM
Application of SAIL phenylalanine and tyrosine with alternative isotope-labeling patterns for protein structure determination
Application of SAIL phenylalanine and tyrosine with alternative isotope-labeling patterns for protein structure determination
Abstract The extensive collection of NOE constraint data involving the aromatic ring signals is essential for accurate protein structure determination, although it is often hampered in practice by the pervasive signal overlapping and tight spin couplings for aromatic rings. We have prepared various types of stereo-array isotope labeled phenylalanines (ε- and ζ-SAIL Phe) and tyrosine (ε-SAIL Tyr) to overcome these problems (Torizawa et al. 2005), and proven...
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01-09-2011 12:46 PM
Recovering lost magnetization: polarization enhancement in biomolecular NMR
Recovering lost magnetization: polarization enhancement in biomolecular NMR
Abstract Experimental sensitivity remains a major drawback for the application of NMR spectroscopy to fragile and low concentrated biomolecular samples. Here we describe an efficient polarization enhancement mechanism in longitudinal-relaxation enhanced fast-pulsing triple-resonance experiments. By recovering undetectable 1H polarization originating from longitudinal relaxation during the pulse sequence, the steady-state 15N polarization becomes enhanced by up to a factor of ~5 with respect to thermal...
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12-31-2010 08:38 PM
Recovering lost magnetization: polarization enhancement in biomolecular NMR.
Recovering lost magnetization: polarization enhancement in biomolecular NMR.
Recovering lost magnetization: polarization enhancement in biomolecular NMR.
J Biomol NMR. 2010 Dec 30;
Authors: Favier A, Brutscher B
Experimental sensitivity remains a major drawback for the application of NMR spectroscopy to fragile and low concentrated biomolecular samples. Here we describe an efficient polarization enhancement mechanism in longitudinal-relaxation enhanced fast-pulsing triple-resonance experiments. By recovering undetectable (1)H polarization...
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12-31-2010 07:03 PM
[NMR paper] Dissection of heteronuclear NMR experiments for studies of magnetization transfer eff
Dissection of heteronuclear NMR experiments for studies of magnetization transfer efficiencies.
Related Articles Dissection of heteronuclear NMR experiments for studies of magnetization transfer efficiencies.
J Magn Reson. 2003 Nov;165(1):89-94
Authors: Braun D, Wüthrich K, Wider G
Modern NMR experiments for applications with biological macromolecules in solution typically include multiple magnetization transfer steps. When working with large structures, a significant fraction of the magnetization is lost during these transfers. For the design...
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11-24-2010 09:16 PM
[U. of Ottawa NMR Facility Blog] Temperature Calibration - An Alternative Method
Temperature Calibration - An Alternative Method
It is well known that the actual temperature of a sample in an NMR probe is not necessarily the same as that read from the variable temperature unit on the spectrometer. This is because the thermocouple used by the variable temperature unit is below the sample tube and not in the center of the rf coil where the NMR measurements are made. One normally must make a calibration plot for the actual temperature vs. the set temperature. For temperatures above room temperature this can be done by employing the known temperature dependent chemical...
19F NMR magnetization transfer between 5-FBAPTA and its complexes. An alternative mea
Linear Mode
