自从利用Cry毒素基因转基因培育抗虫作物品种以来，各国科学家围绕新杀虫材料的筛选与创制进行了广泛探索。多种药物研制已经证明：利用抗独特型抗体技术模拟制备关键活性结构是一项实用的生物模拟技术。前期我们利用该技术已成功从抗体库中制备了具杀虫活性的Cry毒素模拟材料。本项目拟围绕进一步改进模拟物的杀虫活性，运用定向库进化，定点氨基酸替换与分子对接技术，定向制备毒素模拟物。创建高通量“抗独特型抗体-受体”组合筛选体系。对获得的高亲和力模拟物做分子互作分析,首先探明结构域Ⅱ和Ⅲ模拟物的关键结合区特征表位与氨基酸组成，再通过结构域I的基因拼接表达，借助靶向筛选，揭示其结构与受体结合的亲和力与分子互作特性。经多轮害虫杀虫活性测定，制备高杀虫活性模拟物。在此基础上，总结高杀虫活性模拟物的关键活性结构特征，及其与潜在受体的分子互作规律，为研发人源化安全Cry毒素模拟杀虫材料提供理论依据。

Since the use of Cry toxin genes in the breeding of insect resistant crops, the screening and exploration of novel insecticidal genes has been a hot research area in insect toxicology. The selection of anti-idiotype antibodies is a practical technique to create a mimic structure of an active center of a protein which has been verified in the development of many kinds of drugs in medicine industry. By combined using this technique with the phage display technology, we've got series of mimic materials of Cry toxins and showed different insecticidal activities. This project is designed to detect the different affinity and binding kinetics of the Cry toxin mimics with the putative receptors of Cry toxins. We are going to further generate massive amount of the improved mimics by combined use of directed evolution, site-directed mutagenesis, and molecular docking analysis. Then through high-throughput screening by using the connected “anti-idiotype antibody-receptor" system, combined with the molecular interaction analysis, we want to find out the specific antigenic epitopes of the binding regions or single amino acid in the active regions of the mimics of Cry toxin domainⅡ and Ⅲ firstly. Then we'll try to carry out the receptor-oriented screening of different kinds of the expression products by the gene splicing of the domain I, to reveal their binding affinity and its molecular interaction with the receptors. Finally, we hope to finish the preparation of high efficient candidate pesticides, by circular bioassays on several key insect pests, to characterize the key active structures of the analogues and its molecular interaction with the putative receptors, which may provide reference for the research and development of alternative materials of the Cry toxins.