Tao Ke, Long Zhangfu, Liu Kun, Tao Yong, Liu Shigui
National Laboratory of Grassland Biocontrol Engineering, College of Life Science, Sichuan University, Chengdu 610064, People's Republic of China.
Curr Microbiol. 2006 Jan;52(1):45-9. doi: 10.1007/s00284-005-0089-8. Epub 2005 Dec 26.
One or more proteinaceous factors with insecticidal activities in the locust pathogen Serratia marcescens HR-3 culture filtrates were found to cause the death of grassland locusts. A novel insecticidal protein was purified to homogeneity. It was a monomer of 61 kDa. The purified protein showed a strong insecticidal effect with a median lethal dosage of 12.1 microg locust(-1) and contained a high level of protease activity (101 U ml(-1)). Insecticidal activity was significantly decreased when the protein was pretreated with ethylene diamine tetraacetic acid and 1-10-phenanthroline, and it was restored when the treated protein was incubated with Zn(2+). The N-terminal amino acid sequence of insecticidal protein showed sequence similarity with metalloprotease from S. marcescens SM6 and Serratia spp. E15. Our results suggested that the factor primarily responsible for insecticidal activity toward locusts was a zinc-dependent 61-kDa metalloprotease.
在蝗虫病原菌粘质沙雷氏菌HR-3的培养滤液中发现一种或多种具有杀虫活性的蛋白质因子可导致草原蝗虫死亡。一种新型杀虫蛋白被纯化至同质。它是一种61 kDa的单体。纯化后的蛋白显示出很强的杀虫效果，半数致死剂量为12.1 μg/蝗虫，并且含有高水平的蛋白酶活性（101 U/ml）。当该蛋白用乙二胺四乙酸和1,10-菲啰啉预处理时，杀虫活性显著降低，而当处理后的蛋白与Zn²⁺孵育时，活性得以恢复。杀虫蛋白的N端氨基酸序列与粘质沙雷氏菌SM6和沙雷氏菌属E15的金属蛋白酶显示出序列相似性。我们的结果表明，对蝗虫具有杀虫活性的主要因子是一种锌依赖性的61 kDa金属蛋白酶。
