从大豆中纯化棉铃虫组织蛋白酶B抑制因子HCB-SoyI

Purification of an inhibitor of Helicoverpa armigera cathepsin B from soybean seeds

棉铃虫组织蛋白酶B(Helicoverpa armigeracathepsin B,HCB)在胚胎发育过程中降解卵黄蛋白为氨基酸,供给胚胎发育必需的养料,是棉铃虫胚胎正常发育的重要因素。许多植物种子中存在蛋白酶抑制因子,如大豆和向日葵种子。用棉铃虫组织蛋白酶B为酶源,通过硫酸铵沉淀、排阻层析和离子交换层析等方法,从大豆中分离纯化到了一种对HCB有抑制活性的蛋白酶抑制因子,命名为HCB_SoyI。用牛血清白蛋白为底物进一步证明该抑制因子对HCB具有抑制作用。该抑制因子的纯化为进一步克隆其基因奠定了基础,为转基因抗虫作物研究提供了新的候选靶标。

Cathepsin B from Helicoverpa armigera （HCB） plays important role in the life of the cotton bollworm, which degrades yolk proteins to amino acids as nutrients for embryonic development. Many plant seeds, such as soybean seeds and sunflower seeds, contain proteinase inhibitors. An inhibitor, HCB-Soyl, purified from the soybean seeds by ammonium sulfate precipitation, gel filtration and ion-exchange chromatography, was here reported. The inhibitory activity of the inhibitor was further studied with bovine albumin as a substrate. The purified inhibitor offers an opportunity to further clone its gene and may become a new target for insect resistant transgenic plant research.