Department of Entomology, University of Georgia, Athens, GA 30602-2603, USA.
Appl Environ Microbiol. 2009 Nov;75(22):7280-2. doi: 10.1128/AEM.01870-09. Epub 2009 Oct 2.
A peptide from cadherin AgCad1 of Anopheles gambiae larvae was reported as a synergist of Bacillus thuringiensis subsp. israelensis Cry4Ba's toxicity to the Anopheles mosquito (G. Hua, R. Zhang, M. A. Abdullah, and M. J. Adang, Biochemistry 47:5101-5110, 2008). We report that CR11 to the membrane proximal extracellular domain (MPED) (CR11-MPED) and a longer peptide, CR9 to CR11 (CR9-11), from AgCad1 act as synergists of Cry4Ba's toxicity to Aedes aegypti larvae, but a Diabrotica virgifera virgifera cadherin-based synergist of Cry3 (Y. Park, M. A. F. Abdullah, M. D. Taylor, K. Rahman, and M. J. Adang, Appl. Environ. Microbiol. 75:3086-3092, 2009) did not affect Cry4Ba's toxicity. Peptides CR9-11 and CR11-MPED bound Cry4Ba with high affinity (13 nM and 23 nM, respectively) and inhibited Cry4Ba binding to the larval A. aegypti brush border membrane. The longer CR9-11 fragment was more potent than CR11-MPED in enhancing Cry4Ba against A. aegypti.
一种来自冈比亚按蚊幼虫钙粘蛋白 AgCad1 的肽被报道为苏云金芽孢杆菌亚种 israelensis Cry4Ba 对疟蚊（G. Hua、R. Zhang、M. A. Abdullah 和 M. J. Adang，Biochemistry 47:5101-5110, 2008）毒性的增效剂。我们报告说，AgCad1 上的 CR11 到膜近端细胞外域（MPED）（CR11-MPED）和较长的肽 CR9 到 CR11（CR9-11），作为 Cry4Ba 对埃及伊蚊幼虫毒性的增效剂，但一种基于 Diabrotica virgifera virgifera 钙粘蛋白的 Cry3 增效剂（Y. Park、M. A. F. Abdullah、M. D. Taylor、K. Rahman 和 M. J. Adang，Appl. Environ. Microbiol. 75:3086-3092, 2009）则不会影响 Cry4Ba 的毒性。肽 CR9-11 和 CR11-MPED 与 Cry4Ba 具有高亲和力（分别为 13 nM 和 23 nM），并抑制 Cry4Ba 与幼虫 A. aegypti 刷状缘膜的结合。较长的 CR9-11 片段比 CR11-MPED 更能增强 Cry4Ba 对埃及伊蚊的活性。
