中文摘要：

利用同源建模得到杀虫晶体蛋白Cry1Ac的三维结构，之后模拟其与配体N-已酰半乳糖胺的对接，预测关键的氨基酸残基：N482、Q506、S501、L505和V483。Cry1Ac的虚拟突变体与N-已酰半乳糖胺之间的分子对接分析结果表明，R466、R468、R470和R472可能对维持Cry1Ac的DomainⅢ稳定构象起着重要作用。N482和Q506两个残基均含有酰氨基，在对接中易于形成多个氢键，这对稳定对接具有重要作用。研究结果可提供一些有用的信息，用于指导杀虫晶体蛋白的理性设计。

英文摘要：

The 3 -D structure of insecticidal crystal protein Cry1Ac was constructed by homology modeling. The potential docking active cavity was predicted. Molecular docking was simulated between CrylAc and its receptor N -galactosamine. The key residues, N482, Q506, S501, L505 and V483, were predicted. Resuits from the docking simulation between virtual Cry1Ac mutant and N -galactosamine indicated that residues R466, R468, R470 and R472 were important for maintaining a stable conformation of the Domain Ⅲ. N482 and Q506 are liable to form multiple hydrogen bonds, thus are important for a stable docking. The available results in this paper gave helpful imformation for the rational design of insecticidal crystal protein.