INSECTICIDAL TOXIN OF BACILLUS SPHAERICUS 1593 AND 2362

球形芽孢杆菌是一种孢子形成细菌，具有高度的 对某些蚊子种类幼虫的杀虫活性。 这 细菌正在被开发作为微生物控制剂，用于 综合病媒控制方案。 在近40种杀虫剂中 B. Sphaericus目前已知两种非常相似的菌株，1593和 第2362章有着最大的潜力 球形芽孢杆菌 1593通过一种蛋白质毒素杀死蚊子幼虫。50 Kdal， 在孢子形成过程中产生。 这种毒素被包装在 伴孢晶体和在较小程度上在孢子本身。 陶醉 幼虫在摄入大的 B剂量。sphaericus，并可能在短短4小时内死亡。 本提案的目的是开发B的体外测定。 本发明涉及利用培养的蚊子细胞的球形芽孢杆菌毒素，并使用该测定来 研究宿主-病原体相互作用的参数，包括毒素 激活、结合和分子作用模式，以及 细胞的超微结构变化。 毒素将使用 凝胶和离子交换色谱的组合，可能随后是 亲和层析或HPLC层析。 单克隆和多克隆抗体 将用于纯化和定位 毒素

Bacillus sphaericus is a sporeforming bacterium with a high degree of insecticidal activity toward larvae of certain mosquito species. This bacterium is being developed as a microbial control agent for use in integrated vector control programs. Among the nearly 40 insecticidal strains of B. sphaericus currently known two very similar strains, 1593 and 2362, appear to have the greatest potential utility. Bacillus sphaericus 1593 kills mosquito larvae by means of a protein toxin of ca. 50 Kdal, which is produced during sporulation. This toxin is packaged in a parasporal crystal and to a lesser extent in the spore itself. Intoxicated larvae show gut and behavioral symptoms within 1 hr of ingestion of large dose of B. sphaericus, and may die in as little as 4 hr. The objectives of this proposal are to develop an invitro assay for the B. sphaericus toxin utilizing cultured mosquito cells and to use this assay to investigate parameters of the host-pathogen interaction including toxin activation, binding, and molecular mode of action, as well as ultrastructural changes in the cells. Toxin will be purified using a combination of gel and ion exchange chromatography, possibly followed by affinity or HPLC chromatography. Monoclonal and polyclonal antibodies raised to the toxin will be utilized in purification and localization of the toxin.