Lehrstuhl Biopolymere, Universitat Bayreuth, Bayreuth, Germany.
J Am Chem Soc. 2009 Dec 23;131(50):18016-7. doi: 10.1021/ja905412z.
Paramagnetic relaxation enhancement (PRE) has become a useful and widely applied tool in biomolecular NMR spectroscopy. In particular investigations of large complexes or transient contacts benefit from PRE effects. Frequently such studies involve modification of the biomacromolecules under study. We here present a method for editing NMR spectra by utilizing a soluble gadolinium complex that broadens nuclear spins being at or close to the macromolecule-solvent interface. NOE signals in NOESY spectra are selectively attenuated if surface exposed nuclear spins are involved. HSQC-type spectra with paramagnetic agent contain only signals of the interior of the protein, while the corresponding difference spectra harbor signals allocated to surface spins. Thus, the number of signals can be reduced helping to minimize spectral overlap in large proteins. The method reveals additional information about the localization of spins being helpful for structure determination of large complexes.
顺磁弛豫增强（PRE）已成为生物分子 NMR 光谱学中一种有用且广泛应用的工具。特别是对大型复合物或瞬时接触的研究受益于 PRE 效应。此类研究通常涉及被研究的生物大分子的修饰。我们在此提出了一种通过利用可溶的钆配合物来编辑 NMR 谱的方法，该方法可以扩展处于或接近大分子-溶剂界面的核自旋。如果涉及表面暴露的核自旋，则 NOESY 谱中的 NOE 信号会被选择性衰减。含有顺磁试剂的 HSQC 型谱仅包含蛋白质内部的信号，而相应的差谱则包含分配给表面自旋的信号。因此，可以减少信号的数量，有助于减少大型蛋白质中谱线的重叠。该方法揭示了有关自旋定位的附加信息，有助于确定大型复合物的结构。
