Liu H, Smith T J, Lee W M, Mosser A G, Rueckert R R, Olson N H, Cheng R H, Baker T S
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1392.
J Mol Biol. 1994 Jul 8;240(2):127-37. doi: 10.1006/jmbi.1994.1427.
The crystal structure of Fab17-IA, an antigen-binding fragment from a murine immunoglobulin that neutralizes human rhinovirus 14 (HRV14), has been solved to 2.7 A resolution. Fab17-IA crystallized into three different space groups depending upon the method used to purify the intact antibody. The structure was determined by use of molecular and isomorphous replacement methods. The current model has a crystallographic R-factor of approximately 19% for 10,192 independent reflections between 8 and 2.7 A. Correlation coefficient calculations showed that the Fab17-IA structure can be fit into the Fab17-IA/HRV14 image reconstruction density to within 5 A positional accuracy and to within a few degrees of rotation. The resulting interface of the docked antibody was examined and showed extensive charge and shape complementarity with the virus surface that was supported by site-directed mutagenesis experiments. The success of this approach validates the utility of combining X-ray crystallography with cryo-electron microscopy of complex macromolecular assemblies.
已解析出一种来自小鼠免疫球蛋白的抗原结合片段Fab17-IA的晶体结构，其分辨率达到2.7埃，该片段可中和人鼻病毒14型（HRV14）。根据纯化完整抗体所采用的方法，Fab17-IA结晶形成三种不同的空间群。该结构通过分子置换法和同晶置换法确定。对于8至2.7埃之间的10192个独立反射，当前模型的晶体学R因子约为19%。相关系数计算表明，Fab17-IA结构能够以5埃的位置精度和几度的旋转精度拟合到Fab17-IA/HRV14图像重建密度中。对接抗体的最终界面经过检查，显示出与病毒表面广泛的电荷和形状互补性，定点诱变实验也证实了这一点。该方法的成功验证了将X射线晶体学与复杂大分子组装体的冷冻电子显微镜相结合的实用性。
