Improvement of double pulsed field gradient spin‐echo ROESY experiments for identification of bound waters

Abstract

AbstractA novel pulse sequence incorporating the double pulsed field gradient spin‐echo (DPFGSE) and the gradient‐tailored excitation WATERGATE techniques is presented that has particular use for identifying bound waters in 15N‐labeled macromolecules. This sequence, DPFGSE–ROESY–HSQC, affords greater spectral sensitivity than the DPFGSE–ROESY–HMQC experiment which was previously presented and is consequently useful for rapidly obtaining reliable information for characterizing macromolecular bound water molecules. A significant enhancement in the sensitivity is achieved by using the gradient‐tailored excitation WATERGATE sequence in the reverse INEPT step as it allows the use of much higher receiver gains. Since coherence selection is not used, the sequence has improved sensitivity together with less spectral artifacts. The advantage of this pulse sequence is illustrated using 15N‐labeled ribonuclease T1. Copyright © 2003 John Wiley & Sons, Ltd.