中文摘要：

通过同源建模得到了抗癌晶体蛋白Parasporin-2（Cry46Aal）活性区的初始三维结构，利用分子动力学方法对初始三维结构进行优化。为了评估模型的好坏，利用Ramachandran plot和结构匹配等方法对模型进行评价。结果显示，所得的Parasporin-2空间模型良好。比较了Cry46Aal与Cry46Abl这两种高度同源的抗癌晶体蛋白的空间结构，找出了其空间结构上的不同之处。通过大分子对接程序Hex4．5，模拟了Parasporin-2与受体GPI-瞄固蛋白（CD59）的相互作用。结果显示，Parasporin-2中参与对接的活性位点位于两个仪．螺旋下方的凹槽内，而CD59中的四个loop倾向于插入该凹槽内。研究结果为Parasporin-2的抗癌机制研究及其理性改造奠定了基础。

英文摘要：

The initial three dimensional structure of Parasporin-2 （ Cry46Aal ） was constructed by homology modeling method, then was optimized by molecular mechanics method. The quality of the structure was evaluated to be good using Ramachandran plot and structural matching. In addition, the structural difference between Cry46Aal and Cry46Abl was presented. The interaction between Parasporin-2 and its receptor, GPI-anchored protein （CD59） , was simulated using macromolecular docking procedures Hex4.5. It showed that the residues in a groove below two α-helixs of Parasporin-2 were responsible for the interaction, and the four loops of CD59 inserted the groove. The results provided a basis for the rational design of Cry46Aal , and help us to understand the interactions between Cry46Aal and cellular receptor.