...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Synergism of Bacillus thuringiensis toxins by a fragment of a toxin-binding cadherin
【24h】

Synergism of Bacillus thuringiensis toxins by a fragment of a toxin-binding cadherin

机译：毒素结合钙黏着蛋白片段对苏云金芽孢杆菌毒素的协同作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The insecticidal crystal proteins produced by Bacillus thuringiensis (Bt) are broadly used to control insect pests with agricultural importance. The cadherin Bt-R_1 is a binding protein for Bt Cry1A toxins in midgut epithelia of tobacco hornworm (Manduca sexta). We previously identified the Bt-R_1 region most proximal to the cell membrane (CR12-MPED) as the essential binding region required for Cry1Ab-mediated cytotoxicity. Here, we report that a peptide containing this region expressed in Escherichia coli functions as a synergist of Cry1A toxicity against lepidopteran larvae. Far-UV circular dichroism and ~1H-NMR spectroscopy confirmed that our purified CR12-MPED peptide mainly consisted of β-strands and random coils with unfolded structure. CR12-MPED peptide bound brush border membrane vesicles with high affinity (K_d = 32 nM) and insect midgut microvilli but did not alter Cry1Ab or Cry1Ac binding localization in the midgut. By BIAcore analysis we demonstrate that Cry1Ab binds CR12-MPED at high (9 nM)- and low (1 μM)-affinity sites. CR12-MPED-mediated Cry1A toxicity enhancement was significantly reduced when the high-affinity Cry1A-binding epitope (~(1416)GVLTLNIQ~(1423)) within the peptide was altered. Because the mixtures of low Bt toxin dose and CR12-MPED peptide effectively control target insect pests, our discovery has important implications related to the use of this peptide to enhance insecticidal activity of Bt toxin-based biopesticides and transgenic Bt crops.
机译：苏云金芽孢杆菌（Btillus thuringiensis）（Bt）生产的杀虫晶体蛋白被广泛用于控制具有农业重要性的害虫。钙粘蛋白Bt-R_1是烟草天蛾中肠上皮中Bt Cry1A毒素的结合蛋白。我们先前确定最接近细胞膜的Bt-R_1区（CR12-MPED）是Cry1Ab介导的细胞毒性所需的必需结合区。在这里，我们报告说，含有在大肠杆菌中表达的该区域的肽起Cry1A对鳞翅目幼虫毒性的协同作用。远紫外圆二色性和〜1H-NMR光谱证实，我们纯化的CR12-MPED肽主要由β链和具有未折叠结构的无规卷曲组成。 CR12-MPED肽以高亲和力（K_d = 32 nM）和昆虫中肠微绒毛结合刷状缘膜囊泡，但不会改变中肠中Cry1Ab或Cry1Ac的结合位置。通过BIAcore分析，我们证明Cry1Ab在高（9 nM）-和低（1μM）亲和位点结合CR12-MPED。当改变肽段内高亲和力的Cry1A结合表位（〜（1416）GVLTLNIQ〜（1423））时，CR12-MPED介导的Cry1A毒性增强显着降低。由于低Bt毒素剂量和CR12-MPED肽的混合物可有效控制目标害虫，因此我们的发现与使用该肽增强基于Bt毒素的生物农药和转基因Bt作物的杀虫活性有关。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号