Functional Domains of Bacillus thuringiensis Endotoxins

苏云金芽孢杆菌内毒素的功能域

• 批准号: 6858672
• 负责人: DONALD H DEAN
• 金额: $ 43.43万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6858672
• 关键词: Aedes; Anopheles; Bacillus; Culex; aminopeptidase; arthropod nonpollutant control; brush border membrane; cadherins; endotoxins; host organism interaction; protein structure function; receptor; receptor binding

DESCRIPTION (provided by the applicant): Bacillus thuringiensis is a microbial insecticide that is widely used to control insects, including mosquitoes and black flies. The long-range goal of this project is to investigate the binding and mechanism of action of several mosquitocidal proteins against key pestiferous mosquito species, Anopheles gambiae, Aedes aegypti and Culex quinquefaciatus. The main mosquitocidal toxins of interest are the toxins of B. thuringiensis var. israelensis (Bti), Cry4Aa, Cry4Ab and Cry11Aa. Other mosquitocidal toxins, Cry11Ba, Cry19Aa and Cry2Aa, will also be investigated. The hypothesis to be tested is that these toxins bind to specific receptors on the mosquito midgut as recognized in model insect-toxin studies (the Lepidoptera-toxin paradigm); i.e., an array of mosquito midgut proteins (cadherin-like and aminopeptidases) and glycoproteins bind the toxins; and, that domains II and Ill of the are the interacting binding epitopes. A corollary hypothesis is that the reduced ability of mosquitoes to develop resistance to Bti is due to a combination of toxins (Cry4Aa, Cry4Ab and Cry11Aa) each of which binds to a unique receptor or non-competing binding site. The specific aims of the proposal are: (1) Test the competition, saturation and irreversible binding of Cry4Aa, 4Ba, 11Aa, 11Ba, 19Aa and 2Aa toxins to mosquito BBMV and purified receptors. New mosquitocidal activity has been introduced into Cry4Ba (Culex activity) and 19Aa (Aedes activity). The mechanistic basis for these new activities will be investigated. (2) Examine the mechanism of action of mosquitocidal of these toxins, in comparison to the Lepidoptera toxins paradigm; specifically, to define the binding epitopes of these toxins to brush border membrane vesicles (BBMV) of the mosquitoes Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. (3) Examine the nature of mosquito midgut receptors in relation to what has been learned from Lepidoptera receptor paradigm; specifically, to identify the specific binding of these mosquitocidal Cry proteins on aminopeptidases, cadherin-like proteins, glycoproteins and other potential receptors of these mosquitoes.

性状（由申请方提供）：苏云金芽孢杆菌是一种微生物杀虫剂，广泛用于控制昆虫，包括蚊子和黑蝇。该项目的长期目标是研究几种杀蚊蛋白对主要害虫蚊子物种冈比亚按蚊、埃及伊蚊和五带库蚊的结合和作用机制。感兴趣的主要杀蚊毒素是B的毒素。苏云Israelensis（Bti）、Cry4Aa、Cry4Ab和Cry11Aa。其他灭蚊毒素，Cry 11Ba，Cry 19 Aa和Cry 2Aa也将被调查。 待测试的假设是这些毒素结合到蚊子中肠上的特异性受体，如在模型昆虫毒素研究（鳞翅目昆虫毒素范例）中所认识到的;即，一系列蚊子中肠蛋白（钙粘蛋白样和氨基肽酶）和糖蛋白结合毒素;并且，结构域II和III是相互作用的结合表位。一个推论假设是，蚊子对Bti产生抗性的能力降低是由于毒素（Cry 4Aa、Cry 4Ab和Cry 11 Aa）的组合，其中每种毒素结合到独特的受体或非竞争性结合位点。 （1）检测Cry 4Aa、4 Ba、11 Aa、11Ba、19 Aa和2Aa毒素与蚊子BBMV及其纯化受体的竞争、饱和和不可逆结合。新的杀蚊活性已被引入Cry 4 Ba（库蚊活性）和19 Aa（伊蚊活性）。这些新活动的机制基础将进行调查。(2)检查这些毒素的杀蚊作用机制，与鳞翅目毒素范例相比;具体地，定义这些毒素与埃及伊蚊、冈比亚按蚊和致倦库蚊的刷状缘膜囊泡（BBMV）的结合表位。(3)检查蚊子中肠受体的性质与从鳞翅目受体范例中学到的内容;具体地，鉴定这些杀蚊子Cry蛋白对氨基肽酶、钙粘蛋白样蛋白、糖蛋白和这些蚊子的其他潜在受体的特异性结合。