Ice, in addition to â??liquidâ?? water and protein, is an important component of protein samples for NMR spectroscopy at subfreezing temperatures but it has rarely been observed spectroscopically in this context. We characterize its spectroscopic behavior in the temperature range from 100 to 273Â*K, and find that it behaves like pure water ice. The interference of magic-angle spinning (MAS) as well as rf multiple-pulse sequences with Bjerrum-defect motion greatly influences the ice spectra.
[Question from NMRWiki Q&A forum] Relaxation rate of bulk (pure) water at high frequencies
Relaxation rate of bulk (pure) water at high frequencies
Hi all,
Does anyone know if NMR relaxation rates of bulk (pure) water has been measured experimentally at several hundreds of MHz frequencies (say, 500 MHz, though the higher the better) and at room temperature (say, 300K)?
I am aware of some very old publications that reported pure water T1 at 10s of MHz (e.g. Krynicki (1966), Physica 32:167) or at the lower end of the 100s of MHz regime. However, in recent years NMR instruments have been getting better and better and I believe today several hundreds of MHz experiments are...
nmrlearner
News from other NMR forums
0
07-03-2016 08:48 AM
Pure shift NMR
Pure shift NMR
Publication date: April 2015
Source:Progress in Nuclear Magnetic Resonance Spectroscopy, Volumes 86–87</br>
Author(s): Klaus Zangger</br>
Although scalar-coupling provides important structural information, the resulting signal splittings significantly reduce the resolution of NMR spectra. Limited resolution is a particular problem in proton NMR experiments, resulting in part from the limited proton chemical shift range (~10ppm) but even more from the splittings due to scalar coupling to nearby protons. “Pure shift” NMR spectroscopy (also known as...
nmrlearner
Journal club
0
04-12-2015 02:40 AM
Characterization of different water pools in solid-state NMR protein samples
Characterization of different water pools in solid-state NMR protein samples
Abstract We observed and characterized two distinct signals originating from different pools of water protons in solid-state NMR protein samples, namely from crystal water which exchanges polarization with the protein (on the NMR timescale) and is located in the protein-rich fraction at the periphery of the magic-angle spinning (MAS) sample container, and supernatant water located close to the axis of the sample container. The polarization transfer between the water and the protein can be probed by...
nmrlearner
Journal club
0
01-09-2011 12:46 PM
[NMR paper] Observation of reorientationally hindered water in biological tissue using triple qua
Observation of reorientationally hindered water in biological tissue using triple quantum filtered 17O-NMR.
Related Articles Observation of reorientationally hindered water in biological tissue using triple quantum filtered 17O-NMR.
Biochim Biophys Acta. 1995 Jun 9;1244(2-3):253-8
Authors: Flesche CW, Gruwel ML, Deussen A, Schrader J
Water dynamics in aqueous biopolymer solutions often display a two-phase character, resembling water-water and water-protein interactions. Rotationally hindered water molecules in crowded protein environments...
nmrlearner
Journal club
0
08-22-2010 03:41 AM
[NMRwiki tweet] nmrwiki: Unanswered question: For salty #NMR samples - which water suppression is bes
nmrwiki: Unanswered question: For salty #NMR samples - which water suppression is best? http://qa.nmrwiki.org/question/132/
nmrwiki: Unanswered question: For salty #NMR samples - which water suppression is best? http://qa.nmrwiki.org/question/132/
Source: NMRWiki tweets
Hexagonal ice in pure water and biological NMR samples
Linear Mode
