ISSN:
1573-5001
Keywords:
Water exchange
;
NOE
;
Pulsed field gradients
;
Macromolecules
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary A technique for separating intramolecular NOE and solvent-proton exchange peaks in exchange spectroscopy is demonstrated. This method utilizes the large differences in relaxation and coupling properties of water and macromolecules to separate the two effects. The spin-echo filter consists of a water-frequency selective 90° pulse followed by a spin-echo sequence. If the echo time is sufficiently long, protein resonances (e.g. CαH protons) excited by the selective pulse are removed due to their much shorter T2 values and J-coupling evolution. By combining the filter with exchange spectroscopy (EXSY) or water exchange (WEX) filter experiments, exchange peaks can be selectively observed. In this paper the filter is combined with a modified version of the WEX filter (WEX II filter) with 1D and 2D detection and applied to a zinc finger peptide and to staphylococcal nuclease, allowing estimation of the contribution of intramolecular NOEs to the exchange spectra.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00190459
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