Zandomeneghi Giorgia, Williamson Philip T F, Hunkeler Andreas, Meier Beat H
Physical Chemistry, ETH Zurich, ETH-Hönggerberg, CH-8093 Zurich, Switzerland.
J Biomol NMR. 2003 Feb;25(2):125-32. doi: 10.1023/a:1022244025351.
In a model study, the proton NMR spectrum of the opioid pentapeptide leucine-enkephalin associated with bicelles is investigated. The spectral resolution for a static sample is limited due to the large number of anisotropic interactions, in particular strong proton-proton couplings, but resolution is greatly improved by magic-angle sample spinning. Here we present two-dimensional switched-angle spinning NMR experiments, which correlate the high-resolution spectrum of the membrane-bound peptide under magic-angle spinning with its anisotropic spectrum, leading to well-resolved spectra. The two-dimensional spectrum allows the exploitation of the high resolution of the isotropic spectrum, while retaining the structural information imparted by the anisotropic interactions in the static spectrum. Furthermore, switched-angle spinning techniques are demonstrated that allow one to record the proton spectrum of ordered bicellar phases as a function of the angle between the rotor axis and the magnetic field direction, thereby scaling the dipolar interactions by a predefined factor.
在一项模型研究中，对与双分子层相关的阿片类五肽亮氨酸脑啡肽的质子核磁共振谱进行了研究。由于存在大量各向异性相互作用，特别是强质子-质子耦合，静态样品的光谱分辨率受到限制，但通过魔角样品旋转可大大提高分辨率。在此，我们展示了二维切换角旋转核磁共振实验，该实验将魔角旋转下膜结合肽的高分辨率谱与其各向异性谱相关联，从而得到分辨率良好的谱图。二维谱允许利用各向同性谱的高分辨率，同时保留静态谱中各向异性相互作用赋予的结构信息。此外，还展示了切换角旋转技术，该技术能让人们记录有序双分子层相的质子谱作为转子轴与磁场方向之间角度的函数，从而将偶极相互作用按预定因子进行缩放。
