BUILDUP RATES OF THE NUCLEAR OVERHAUSER EFFECT MEASURED BY TWO-DIMENSIONAL PROTON MAGNETIC-RESONANCE SPECTROSCOPY - IMPLICATIONS FOR STUDIES OF PROTEIN CONFORMATION
BUILDUP RATES OF THE NUCLEAR OVERHAUSER EFFECT MEASURED BY TWO-DIMENSIONAL PROTON MAGNETIC-RESONANCE SPECTROSCOPY - IMPLICATIONS FOR STUDIES OF PROTEIN CONFORMATION
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DOI：
10.1021/ja00403a008
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发表时间：
1981-01-01
影响因子：
15
通讯作者：
WUTHRICH, K
中科院分区：
文献类型：
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作者：
KUMAR, A;WAGNER, G;WUTHRICH, K
通过碱性胰蛋白酶抑制剂的实验证明，核奥弗豪瑟效应的累积速率可以通过二维核磁共振波谱测量。建立了由紧密间隔的质子之间的直接偶极-偶极耦合引起的一阶欧沃豪瑟效应的累积速率与蛋白质构象中的质子-质子距离之间的定性相关性。还确定了由于更远的质子之间的交叉弛豫引起的自旋扩散而产生的二阶奥沃豪瑟效应。在这些观察的基础上，讨论了二维核欧沃豪塞增强光谱研究生物大分子构象的潜力和局限性，并为改进实验程序提出了建议。对于 Overhauser 效应的定量测量，使用相敏光谱和选择性抑制以非常短的混合时间记录的数据集中的 J 交叉峰的技术显得尤为重要。
It is demonstrated, by experiments with the basic pancreatic trypsin inhibitor, that the buildup rates of the nuclear Overhauser effect can be measured by 2-dimensional NMR spectroscopy. Qualitative correlations between the buildup rates of 1st-order Overhauser effects, which arise from direct dipole-dipole coupling between closely spaced protons, and the proton-proton distances in the protein conformation are established. Second-order Overhauser effects due to spin diffusion by cross-relaxation between more distant protons are also identified. On the basis of these observations, potentialities and limitations of 2-dimensional nuclear Overhauser enhancement spectroscopy for studies of the conformations of biological macromolecules are discussed and suggestions made for improved experimental procedures. For quantitative measurements of Overhauser effects, the use of phase-sensitive spectra and of techniques for selective suppression of J cross-peaks in data sets recorded with very short mixing times appears particularly important.