In a previous post I emphasized the importance of cleaning the outside of your NMR tube before putting samples in the NMR magnet. The "stuff" from your fingers (on the outside of your NMR tube) accumulates on the inside of the NMR probe coil inserts and can cause spinning problems, shimming problems and problems with inserting or ejecting samples. Furthermore, the accumulation of "stuff" causes a significant background signal. The figure below shows the top of an NMR probe before and after cleaning.
The probe was in use for several months before cleaning. Notice the sticky black "stuff" present in the photo on the left. Please take care in cleaning your NMR tubes before putting them in the spectrometer.
NMR of hyperpolarised probes
From the The DNP-NMR Blog:
NMR of hyperpolarised probes
Witte, C. and L. Schroder, NMR of hyperpolarised probes. NMR Biomed, 2012: p. n/a-n/a.
http://www.ncbi.nlm.nih.gov/pubmed/23033215
nmrlearner
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04-15-2013 08:52 AM
[CNS Yahoo group] Quick-and-dirty searches of both PDB and EMDB at PDBe
Quick-and-dirty searches of both PDB and EMDB at PDBe
Hi all, As part of its recent winter update, the Protein Data Bank in Europe (PDBe; http://pdbe.org/) has improved its facility that allows for tandem searches
More...
nmrlearner
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04-01-2011 09:31 PM
[NMR paper] Nmr probes of molecular dynamics: overview and comparison with other techniques.
Nmr probes of molecular dynamics: overview and comparison with other techniques.
Related Articles Nmr probes of molecular dynamics: overview and comparison with other techniques.
Annu Rev Biophys Biomol Struct. 2001;30:129-55
Authors: Palmer AG
NMR spin relaxation spectroscopy is a powerful approach for characterizing intramolecular and overall rotational motions in proteins. This review describes experimental methods for measuring laboratory frame spin relaxation rate constants by high-resolution solution-state NMR spectroscopy, together...
nmrlearner
Journal club
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11-19-2010 08:32 PM
[Question from NMRWiki Q&A forum] Please suggest experiments that push the power limits of NMR probes
Please suggest experiments that push the power limits of NMR probes
I'm trying to come up with reasonable tests of probe performance for all channels by simulating conditions at which arcing is most likely to occur.
For those tests I usually read voltage of the incoming wave on the RF line using directional coupler with a 50dB attenuated pickup and oscilloscope after running an "experiment" pulsing at the power and duty cycle that simulates the condition to be tested. If the waveform looks nice and square - there is no arcing.
What experiments should I look into? OK for 1H I'd pick...
nmrlearner
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10-08-2010 02:35 AM
[NMR paper] Use of paramagnetic NMR probes for structural analysis in cytochrome c3 from Desulfov
Use of paramagnetic NMR probes for structural analysis in cytochrome c3 from Desulfovibrio vulgaris.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles Use of paramagnetic NMR probes for structural analysis in cytochrome c3 from Desulfovibrio vulgaris.
Eur J Biochem. 1997 Mar 15;244(3):721-34
Authors: Salgueiro CA, Turner DL, Xavier AV
The dipolar field generated by each of the four haems in the tetrahaem ferricytochrome c3 from...
nmrlearner
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08-22-2010 03:31 PM
[NMR paper] H NMR probes for inter-segmental hydrogen bonds in myoglobins.
H NMR probes for inter-segmental hydrogen bonds in myoglobins.
Related Articles H NMR probes for inter-segmental hydrogen bonds in myoglobins.
J Biochem. 1996 Jul;120(1):126-32
Authors: Yamamoto Y
NMR signals arising from the HisB5 N delta H and HisEF5 N epsilon H protons in sperm whale skeletal and horse heart myoglobins have been located for the first time in the downfield shifted portion of the spectra. The shifts and hydrogen exchange rates indicate that these His imidazole ring NH protons are involved in the inter-segmental hydrogen bonds...
nmrlearner
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08-22-2010 02:27 PM
[NMR paper] NMR identification of protein surfaces using paramagnetic probes.
NMR identification of protein surfaces using paramagnetic probes.
Related Articles NMR identification of protein surfaces using paramagnetic probes.
Biochemistry. 1990 Oct 30;29(43):10041-8
Authors: Petros AM, Mueller L, Kopple KD
Paramagnetic agents produce line broadening and thus cancellation of anti phase cross-peak components in two-dimensional correlated nuclear magnetic resonance spectra. The specificity of this effect was examined to determine its utility for identifying surface residues of proteins. Ubiquitin and hen egg white...
Dirty NMR Probes
Linear Mode
