Kern Thomas, Schanda Paul, Brutscher Bernhard
Laboratoire de RMN, Institut de Biologie Structurale Jean-Pierre Ebel, CEA/Centre National de la Recherche Scientifique, UJF, 41 rue Jules Horowitz, Grenoble Cedex, France.
J Magn Reson. 2008 Feb;190(2):333-8. doi: 10.1016/j.jmr.2007.11.015. Epub 2007 Nov 28.
The SOFAST-HMQC experiment [P. Schanda, B. Brutscher, Very fast two-dimensional NMR spectroscopy for real-time investigation of dynamic events in proteins on the time scale of seconds, J. Am. Chem. Soc. 127 (2005) 8014-8015] allows recording two-dimensional correlation spectra of macromolecules such as proteins in only a few seconds acquisition time. To achieve the highest possible sensitivity, SOFAST-HMQC experiments are preferably performed on high-field NMR spectrometers equipped with cryogenically cooled probes. The duty cycle of over 80% in fast-pulsing SOFAST-HMQC experiments, however, may cause problems when using a cryogenic probe. Here we introduce SE-IPAP-SOFAST-HMQC, a new pulse sequence that provides comparable sensitivity to standard SOFAST-HMQC, while avoiding heteronuclear decoupling during (1)H detection, and thus significantly reducing the radiofrequency load of the probe during the experiment. The experiment is also attractive for fast and sensitive measurement of heteronuclear one-bond spin coupling constants.
SOFAST-HMQC实验[P. 尚达、B. 布鲁彻，《用于实时研究蛋白质中秒级动态事件的超快速二维核磁共振光谱》，《美国化学会志》127 (2005) 8014 - 8015]能够在仅几秒的采集时间内记录蛋白质等大分子的二维相关光谱。为实现尽可能高的灵敏度，SOFAST-HMQC实验最好在配备低温冷却探头的高场核磁共振光谱仪上进行。然而，快速脉冲SOFAST-HMQC实验中超过80%的占空比在使用低温探头时可能会引发问题。在此，我们引入SE-IPAP-SOFAST-HMQC，这是一种新的脉冲序列，它能提供与标准SOFAST-HMQC相当的灵敏度，同时在氢检测期间避免异核去耦，从而在实验过程中显著降低探头的射频负载。该实验对于快速且灵敏地测量异核一键自旋耦合常数也很有吸引力。
