苏云金芽孢杆菌杀虫晶体蛋白毒性片段的结构域在毒杀昆虫中的作用

苏云金芽孢杆菌 (Bacillusthuringiensis)杀虫晶体蛋白的毒性片段包含三个不同的结构域。通过对毒性片段编码基因的定点诱变和体外重组 ,已经对结构域的功能有了较清晰的认识。一般认为结构域Ⅰ参与孔道的形成 ,结构域Ⅱ决定毒素与受体的特异性结合 ,结构域Ⅲ主要调节毒素的活性。本文根据国外研究 ,从毒素蛋白质结构的不同组织层次 ,阐述了这些区域的结构与其功能的关系。

The Function for the Toxic Fragment of Bacillus thuringiensis Insecticidal Crystal Proteins to Cause Death of Larvae

The toxic fragment of Bacillus thuringiensis insecticidal crystal proteins (ICPs) consists of three distinct structural domains.More clear elucidation about functions for the three domains has been presented through site-directed mutagenesis and in vitro recombination to the toxic fragment.It is generally believed that domain I is involved in pore formation and domain II contributes to receptor binding and specificity while domain III appears to modulate the activity of toxins.According to recent research progress from abroad in the field of the mechanism of toxicity of Bt ICPs,this review elucidates the correlation between the domain's structure and its function from different levels of the toxic peptide. ;