Functional Analysis of Two Processed Fragments of Bacillus thuringiensis Cry11A Toxin
Functional Analysis of Two Processed Fragments of Bacillus thuringiensis Cry11A Toxin
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DOI：
10.1271/bbb.68.523
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发表时间：
2004-01
期刊：
影响因子：
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通讯作者：
Masashi Yamagiwa;Kohei Sakagawa;H. Sakai
中科院分区：
文献类型：
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作者：
Masashi Yamagiwa;Kohei Sakagawa;H. Sakai
双翅目昆虫特异性杀虫蛋白Cry11A的70-kDa原毒素被胰蛋白酶加工成36-和32-kDa片段。为了研究两个加工片段的有效功能，构建了每个多肽的GST（谷胱甘肽-S-转移酶）融合蛋白。虽然36-也不是32-kDa的片段是有毒的尖音库蚊幼虫，两个片段的共表达恢复了杀虫活性。此外，共沉淀实验证明36-kDa片段与32-kDa片段缔合。因此，表明Cry11A的两个加工片段的共存是毒性的关键。突变体的36-kDa片段缺乏从Gly257到Arg360的区域结合到32-kDa片段，但与32-kDa片段的共表达导致没有毒性，这表明该区域参与杀虫活性。
The 70-kDa protoxin of Cry11A, a dipteran-specific insecticidal protein, was processed by trypsin into 36- and 32-kDa fragments. To investigate the potent function of the two processed fragments, a GST (Glutathione-S-transferase) fusion protein of each polypeptide was constructed. While neither the 36- nor the 32-kDa fragment was toxic to Culex pipiens larvae, coexpression of the two fragments restored the insecticidal activity. Furthermore, the coprecipitation experiment demonstrated that the 36-kDa fragment was associated with the 32-kDa fragment. It was, therefore, shown that the coexistence of the two processed fragments of Cry11A was essential for the toxicity. The mutant of the 36-kDa fragment lacking the region from Gly257 to Arg360 bound to the 32-kDa fragment but the coexpression with the 32-kDa fragment resulted in no toxicity, suggesting that this region was involved in insecticidal activity.