中文摘要：

通过同源建模，得到Ⅰ型抗癌晶体蛋白Parasporin-1的初始三维结构．经分子动力学方法优化后，利用Ramachandran Plot检测和结构匹配等方法对模型进行评价．结果显示，结构模型中的键长、键角及二面角的分布合理，与模板蛋白的主链a碳原子的均方根差值为0．537592，在合理范围之内．此外，通过分析Parasporin-1结构域I中的β-loop-β结构片段，推测出第2个蛋白酶处理激活位点的位置在两个芳香族疏水性氨基酸F167与Y168之间．

英文摘要：

The structure of Parasporin-1, the first cancer cell-killing crystal protein from Bacillus thuringiensis, was constructed using homology modeling, and was optimized by molecular mechanics method. The simulated structure was evaluated using Ramachandran Plot and structural matching. The distributions of bond length, bond angel, and dihedral angle were rational. The RMSD （root-mean-square deviation） value of a-carbon atom on the main chain between Parasporin-1 and model protein was 0. 537 592, which was within reasonable bounds. The analysis of β-loop-β motif in Domain I suggest that the second site digested by proteinase K were located between F167 and Y168.