Wagner G, Braun W, Havel T F, Schaumann T, Go N, Wüthrich K
Institut für Molekularbiologie und Biophysik Eidgenössische Technische Hochschule-Hönggerberg, Zürich, Switzerland.
J Mol Biol. 1987 Aug 5;196(3):611-39. doi: 10.1016/0022-2836(87)90037-4.
A set of conformational restraints derived from nuclear magnetic resonance (n.m.r.) measurements on solutions of the basic pancreatic trypsin inhibitor (BPTI) was used as input for distance geometry calculations with the programs DISGEO and DISMAN. Five structures obtained with each of these algorithms were systematically compared among themselves and with the crystal structure of BPTI. It is clear that the protein architecture observed in single crystals of BPTI is largely preserved in aqueous solution, with local structural differences mainly confined to the protein surface. The results confirm that protein conformations determined in solution by combined use of n.m.r. and distance geometry are a consequence of the experimental data and do not depend significantly on the algorithm used for the structure determination. The data obtained further provide an illustration that long intramolecular distances in proteins, which are comparable with the radius of gyration, are defined with high precision by relatively imprecise nuclear Overhauser enhancement measurements of a large number of much shorter distances.
一组从对碱性胰蛋白酶抑制剂（BPTI）溶液进行核磁共振（n.m.r.）测量得出的构象限制条件，被用作使用DISGEO和DISMAN程序进行距离几何计算的输入。用这些算法中的每一种得到的五个结构，在它们彼此之间以及与BPTI的晶体结构之间进行了系统比较。很明显，在BPTI单晶中观察到的蛋白质结构在水溶液中基本得以保留，局部结构差异主要局限于蛋白质表面。结果证实，通过联合使用n.m.r.和距离几何在溶液中确定的蛋白质构象是实验数据的结果，并且在很大程度上不依赖于用于结构确定的算法。所获得的数据进一步说明了，蛋白质中与回转半径相当的长分子内距离，是通过对大量短得多的距离进行相对不精确的核Overhauser增强测量而高精度定义的。
