类钙粘蛋白对Cry3A毒素杀虫活性的影响

The effect of cadherin on the insecticidal activity of Cry3A toxin

将克隆的黄粉虫类钙粘蛋白基因片段在大肠杆菌中表达纯化,并分析其对Cry3A毒素杀虫活性的影响,从而探讨黄粉虫类钙粘蛋白对Cry3A毒素杀虫活性的增效作用。黄粉虫类钙粘蛋白基因片段在大肠杆菌中表达产物为包涵体,经尿素变性后,用亲和纯化法可得到较纯的重组蛋白;随着类钙粘蛋白片段与Cry3A质量比值的升高,Cry3A毒素对黄粉虫的杀虫活性也逐步提高,当其比值为1时,活性达到最大,提高了2.5倍,而黄粉虫类钙粘蛋白片段对Cry3Am的杀虫活性却没有显著性影响。研究表明,黄粉虫类钙粘蛋白对Cry3A毒素的杀虫活性具有增效作用。

In order to analyze the synergistic effect of cadherin from Tenebrio molitor to Cry3A toxin,the gene fragment of cadherin cloned from the midgut of T.molitor was expressed in Escherichia coli to evaluate the effect of cadherin on the insecticidal activity of Cry3A toxin.The expressed product of cadherin-Tm gene fragment is inclusion body,which is denatured by urea,followed by affinity chrymatography.The insecticidal activity of Cry3A toxin is enhancing corresponding to the increasing of the mass ratio of cadherin-Tm fragment to Cry3A toxin.When the ratio is about 1,there is a maximum insecticidal activity of Cry3A toxin,which is 2.5 fold higher than that of Cry3A toxin.However,cadherin-Tm fragment has no effect on the insecticidal activity of Cry3Am.This research indicated that cadherin-Tm fragment has enhancing effect just on Cry3A toxin.