Abstract
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.
Original language | English (US) |
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Pages (from-to) | 77-82 |
Number of pages | 6 |
Journal | Journal of Biomolecular NMR |
Volume | 7 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 1996 |
Keywords
- Macromolecules
- NOE
- Pulsed field gradients
- Water exchange
ASJC Scopus subject areas
- Biochemistry
- Spectroscopy