FUNCTINAL DOMAINS OF BACCILLUS THURINGIENSIS ENDOTOXINS

苏云金芽孢杆菌是一种微生物杀虫剂，广泛用于 控制多种昆虫，包括农业害虫;以及蚊子 和黑蝇，人类疾病的传播媒介。 有源组件包括 杀虫晶体蛋白或Cry毒素。 这些杀虫 蛋白质可以通过遗传和蛋白质工程来操纵， 改变和改善他们的活动。 本项目的总体目标是详细调查 几种Cry毒素与已知受体结合并提高杀虫活性 通过改善与受体的结合来提高活性。 具体目标 是鉴定Cry毒素上的氨基酸残基 并通过实验改变这些残基， 所述取代的残基增强结合和毒性。 这将是 通过定点诱变的遗传技术完成。 受体上负责相互作用的成分 也将通过生化方法来检测 拟议 研究采用了一种模型系统，该系统由已知的cry毒素组成。 作为一个良好的表征受体的结构。 当基本 了解毒素-受体相互作用，这可以使用 来提高Cry毒素对蚊子的杀伤力

Bacillus thuringiensis is a microbial insecticide that is widely used to control numerous insects, including agricultural pests; and, mosquitoes and blackflies, vectors of human diseases. The active components are the insecticidal crystal proteins or Cry toxins. These insecticidal proteins may be manipulated by genetic and protein engineering to alter and improve their activity. The overall goal of this project is to investigate in detail the binding of several Cry toxins to a known receptor and improve the insecticidal activity by improving the binding to the receptor. The specific aims are to identify the amino acid residues on the Cry toxins that interact with the receptor and to experimentally alter these residues to identify which substituted residues enhance binding and toxicity. This will be accomplished by the genetic technique of site-directed mutagenesis. The components on the receptor that are responsible for interaction with the toxin will also be determined biochemically. The proposed research employs a model system consisting of a cry toxins of known structure as a well characterized receptor. When the basic understanding of toxin-receptor interaction is obtained, this may used to improve Cry toxins against the mosquito.