Madrid M, Jardetzky O
Stanford Magnetic Resonance Laboratory, Stanford University, CA 94305-5055.
Biochim Biophys Acta. 1988 Mar 2;953(1):61-9. doi: 10.1016/0167-4838(88)90009-x.
Nuclear Overhauser enhancement (NOESY) spectra were theoretically generated by solving the generalized Bloch equations with the appropriate initial conditions. The input to the equations were the coordinates of the protons of two similar crystal structures of basic pancreatic trypsin inhibitor. The two NOESY spectra obtained were compared to published experimental spectra of the protein in solution. It was found that the two crystal structures of basic pancreatic trypsin inhibitor give different theoretical spectra. The solution of the Bloch equations is very sensitive to small variations in the distance between protons (approx. 0.2 A), and to differences in the surrounding configurations. The method allows a detailed comparison of the crystal and solution structures of proteins. The structure of the trypsin inhibitor in solution was found to be similar to either one or the other crystal forms in different regions of the molecule.
通过在适当的初始条件下求解广义布洛赫方程，从理论上生成了核欧沃豪斯效应（NOESY）谱。方程的输入是碱性胰蛋白酶抑制剂的两种相似晶体结构中质子的坐标。将得到的两个NOESY谱与已发表的该蛋白质在溶液中的实验谱进行比较。结果发现，碱性胰蛋白酶抑制剂的两种晶体结构给出了不同的理论谱。布洛赫方程的解对质子间距离的微小变化（约0.2埃）以及周围构型的差异非常敏感。该方法允许对蛋白质的晶体结构和溶液结构进行详细比较。发现溶液中胰蛋白酶抑制剂的结构在分子的不同区域与其中一种或另一种晶体形式相似。
