Zangger K, Armitage I M
Department of Biochemistry, University of Minnesota, Medical School, 4-225 Millard Hall, 435 Delaware Street S.E., Minneapolis, Minnesota, 55455, USA.
J Magn Reson. 1998 Nov;135(1):70-5. doi: 10.1006/jmre.1998.1531.
An experiment is presented which allows for the sensitivity-enhanced measurement of proton exchange rates in a HSQC type experiment. Instead of using INEPT type transfer of magnetization from protons to heteronuclei and vice versa, we have used heteronuclear Hartmann-Hahn transfer, which is known to have higher sensitivity in the presence of chemical exchange. Direct NOE's between NH protons and alpha-protons are suppressed by an exchange-editing step unless the alpha-resonances are degenerate with the water resonance. A comparison between the exchange-edited HEHAHA-HSQC and a standard exchange-edited HSQC experiment performed on the uniformly 15N-labeled staphylococcal nuclease H124L shows an enhancement of approximately 100% with the former experiment. A set of one-dimensional exchange-edited spectra of urea was used for evaluating the ability to extract exchange rates using the presented experiment.
本文介绍了一种实验，该实验可在HSQC类型实验中实现质子交换率的灵敏度增强测量。我们没有使用INEPT类型的磁化从质子到异核的转移以及反之亦然，而是使用了异核Hartmann-Hahn转移，已知在存在化学交换的情况下其灵敏度更高。除非α-共振与水共振简并，否则通过交换编辑步骤可抑制NH质子与α-质子之间的直接NOE。在对均匀15N标记的葡萄球菌核酸酶H124L进行的交换编辑HEHAHA-HSQC和标准交换编辑HSQC实验之间的比较表明，前一个实验的增强约为100%。使用一组尿素的一维交换编辑光谱来评估使用所提出的实验提取交换率的能力。
