Song H W, Chang W R, Liang D C
Institute of Biophysics, Academia Sinica, Beijing, PRC.
Sci China B. 1993 Feb;36(2):187-95.
Based on the crystal symmetry of [L-Met]B0 bovine insulin (LMBBI) and the fundamental theory of the molecular packing method, the scheme for the determination of the position and orientation of the molecules by only using one-dimensional rotation and one-dimensional translation was chosen to be used, and therefore the calculation of the rotation function of the molecular replacement method and the refinement of the rotational and translational parameters by using the R-factor search method were simplified greatly. After the preliminary refinement by using the macromolecular rigid body refinement technique, the molecular model was further refined and adjusted by using the energy-minimizing stereochemical-restrained least squares refinement technique assisted by the manual revision on the difference Fourier maps. The L-Met residues on the N-terminus of the B-chain appeared clearly on the final electron density map.
基于[L-蛋氨酸]B0牛胰岛素（LMBBI）的晶体对称性以及分子堆积方法的基本理论，选择了仅使用一维旋转和一维平移来确定分子位置和取向的方案，从而大大简化了分子置换法旋转函数的计算以及使用R因子搜索法对旋转和平移参数的精修。在使用大分子刚体精修技术进行初步精修后，通过能量最小化立体化学约束最小二乘精修技术，并辅以对差值傅里叶图的人工修正，对分子模型进行了进一步的精修和调整。B链N端的L-蛋氨酸残基在最终电子密度图上清晰可见。
