Reduction of Bacillus thuringiensis Cry1Ac toxicity against Helicoverpa armigera by a soluble toxin-binding cadherin fragment
Reduction of Bacillus thuringiensis Cry1Ac toxicity against Helicoverpa armigera by a soluble toxin-binding cadherin fragment
复制标题
通过可溶性毒素结合钙粘蛋白片段减少苏云金芽孢杆菌 Cry1Ac 对棉铃虫的毒性
DOI：
10.1016/j.jinsphys.2009.05.001
复制
发表时间：
2009-08-01
影响因子：
2.2
通讯作者：
Oppert, Brenda
中科院分区：
文献类型：
--
作者：
Liu, Chenxi;Wu, Kongming;Oppert, Brenda
在棉铃虫中，一个类钙粘素蛋白被鉴定为苏云金芽孢杆菌(Bt)Cry1Ac毒素的可能受体，并在Bt杀虫作用中发挥关键作用。在本研究中，我们从棉铃虫Cry1Ac毒素结合钙粘附素中获得了一个片段，该片段包括预测的毒素结合区。Cry1Ac毒素与该钙粘附素片段的结合促进了250 kDa毒素寡聚体的形成。通过配基印迹、结合试验和生物测定，评价了该钙粘蛋白片段对Cry1Ac毒素结合和毒性的影响。配基印迹和结合分析结果表明，在体外变性或自然条件下，Cry1Ac与棉铃虫中肠上皮细胞的结合减少。生物测定结果表明，棉铃虫钙粘蛋白片段在体内可降低Cry1Ac原毒素或活化毒素的毒性。钙粘附素片段的加入对Cry2Ab的毒性没有影响。(C)2009爱思唯尔有限公司。保留所有权利。
A cadherin-like protein has been identified as a putative receptor for Bacillus thuringiensis (Bt) Cry1Ac toxin in Helicoverpa armigera and plays a key role in Bt insecticidal action. In this study, we produced a fragment from this H. armigera Cry1Ac toxin-binding cadherin that included the predicted toxin-binding region. Binding of Cry1Ac toxin to this cadherin fragment facilitated the formation of a 250-kDa toxin oligomer. The cadherin fragment was evaluated for its effect on Cry1Ac toxin-binding and toxicity by ligand blotting, binding assays, and bioassays. The results of ligand blotting and binding assays revealed that the binding of Cry1Ac to H. armigera midgut epithelial cells was reduced under denaturing or native conditions in vitro. Bioassay results indicated that toxicities from Cry1Ac protoxin or activated toxin were reduced in vivo by the H. armigera cadherin fragment. The addition of the cadherin fragment had no effect on Cry2Ab toxicity. (C) 2009 Elsevier Ltd. All rights reserved.