QUANTITATIVE-DETERMINATION OF CONFORMATIONS OF FLEXIBLE MOLECULES IN SOLUTION USING LANTHANIDE IONS AS NUCLEAR MAGNETIC-RESONANCE PROBES - APPLICATION TO ADENOSINE-5'-MONOPHOSPHATE
QUANTITATIVE-DETERMINATION OF CONFORMATIONS OF FLEXIBLE MOLECULES IN SOLUTION USING LANTHANIDE IONS AS NUCLEAR MAGNETIC-RESONANCE PROBES - APPLICATION TO ADENOSINE-5'-MONOPHOSPHATE
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DOI：
10.1016/0022-2836(74)90110-7
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发表时间：
1974-01-01
影响因子：
5.6
通讯作者：
XAVIER, AV
中科院分区：
文献类型：
--
作者：
BARRY, CD;GLASEL, JA;XAVIER, AV
本文介绍了一种方法，即在特定的镧系元素阳离子干扰下，研究柔性分子在溶液中的构象。磁扰动有两种：在阳离子如Eu 3+的存在下，核磁共振谱线的位移和在阳离子如Gd 3+的存在下，核磁共振激发的弛豫速率的变化。合适的表达式给出的扰动的大小和几何形状的镧系络合物在没有通过键扰动和轴对称系统之间的关系。它被证明，这里描述的光谱变化不是由于通过键（接触）的影响。的情况下，其中磁化率张量的各向异性，如在核磁共振谱中看到的，是轴对称的，被定义。所描述的实验系统就是这种类型。我们设计了一个计算机程序，用来寻找与核磁共振数据相符合的分子构象，本文概述了该方法的原理，以及我们如何结合弛豫探针和位移探针来获得pH为2的5′-单磷酸腺苷的构象。结果表明，一个小的家庭密切相关的构象适合核磁共振数据。这些构象与AMP的晶体结构非常相似。
A procedure is described here whereby the conformation, of a flexible molecule in solution can be found. The method depends on the study of the nuclear magnetic resonance spectrum of the molecule in the presence of perturbations due to specifically bound lanthanide cations. The magnetic perturbations are of two kinds: shifts of nuclear magnetic resonance spectral lines in the presence of cations such as Eu3+and changes in relaxation rates of the nuclear magnetic resonance excitations in the presence of cations such as Gd3+. Suitable expressions are given for the relation between the magnitude of the perturbations and the geometry of the lanthanide complex in the absence of through-bond perturbations and for an axially symmetric system. It is proved that the spectral changes described here are not due to through-bond (contact) effects. The circumstances, in which the anisotropy of the magnetic susceptibility tensor, as seen in the nuclear magnetic resonance spectra, is of axial symmetry, are defined. The experimental systems described are of this kind. A computer program has been devised that searches for the conformations of the molecule which fit the nuclear magnetic resonance data.We outline here the principles of the method and how we have used a combination of relaxation and shift probes to obtain the conformation of adenosine-5′-monophosphate at pH 2. It is shown that a small family of closely related conformations fit the nuclear magnetic resonance data. These conformations are very similar to that of the crystal structure of AMP.