Habazettl J, Schleicher M, Otlewski J, Holak T A
Max-Planck-Institut für Biochemie, Martinsried bei München, Germany.
J Mol Biol. 1992 Nov 5;228(1):156-69. doi: 10.1016/0022-2836(92)90498-9.
The solution structures of two proteins (CMTI-I, a trypsin inhibitor from Cucurbita maxima, and hisactophilin, an actin binding protein of 118 amino acids) have been determined based on the NOE data derived solely from the homonuclear 3D NOE-NOE magnetic resonance spectroscopy. Two different approaches for extraction of the structural information from the 3D NOE-NOE experiment were tested. One approach was based on the transformation of the 3D intensities into distance constraints. In the second, and more robust approach, the 3D NOE intensities were used directly in structure calculations, without the need to transform them into distance constraints. A new 2D potential function representing the 3D NOE-NOE intensity was developed and used in the simulated annealing protocol. For CMTI-I, a comparison between structures determined with the 3D NOE-NOE method and various 2D NOE approaches was carried out. The 3D data set allowed better definition of the structures than was previously possible with the 2D NOE procedures that used the isolated two-spin approximation to derive distance information.
基于仅从同核三维NOE-NOE磁共振光谱获得的NOE数据，已确定了两种蛋白质（CMTI-I，一种来自南瓜的胰蛋白酶抑制剂；亲肌动蛋白，一种由118个氨基酸组成的肌动蛋白结合蛋白）的溶液结构。测试了从三维NOE-NOE实验中提取结构信息的两种不同方法。一种方法是基于将三维强度转化为距离约束。第二种更稳健的方法是直接在结构计算中使用三维NOE强度，无需将其转化为距离约束。开发了一种表示三维NOE-NOE强度的新二维势函数，并将其用于模拟退火协议。对于CMTI-I，对用三维NOE-NOE方法确定的结构与各种二维NOE方法进行了比较。与之前使用孤立双自旋近似来推导距离信息的二维NOE程序相比，三维数据集能够更好地定义结构。
