目的克隆获取冬虫夏草指标蛋白氰酸酶(IP4)的c DNA全长及对其抗原表位预测。方法结合课题组前期采用蛋白组学法筛选得到的冬虫夏草指标性蛋白IP4和冬虫夏草转录组数据,挖掘IP4 m RNA序列,并克隆IP4 c DNA全长,通过NCBI结构分析服务系统...目的克隆获取冬虫夏草指标蛋白氰酸酶(IP4)的c DNA全长及对其抗原表位预测。方法结合课题组前期采用蛋白组学法筛选得到的冬虫夏草指标性蛋白IP4和冬虫夏草转录组数据,挖掘IP4 m RNA序列,并克隆IP4 c DNA全长,通过NCBI结构分析服务系统对IP4进行保守区和功能区分析,利用DNAMAN 6.0和DNAStar软件分别进行序列比对和抗原表位分析。结果从转录组数据中挖掘到IP4的2个可变剪接体,属于内含子保留的可变剪接。RT-PCR结果显示,IP4 c DNA全长465 bp,编码154 aa(氨基酸)。IP4蛋白的保守区和主要催化活性位点位于87～154 aa,该区域为氰酸酶家族保守核心区域和二聚体结合区域,DNAMAN 6.0分析结果表明1～39 aa和55～81 aa区具有较高种属特异性,DNAStar预测IP4蛋白的抗原表位区主要分布于25～90 aa。结论最终确定IP4的25～39 aa和55～81 aa为最佳抗原特异区,为后续规模化制备IP4蛋白特异抗原区及免疫法鉴定冬虫夏草奠定基础。展开更多
Grass carp （Ctenopharyngodon idella） is an important species of freshwater aquaculture fish in China. However, grass carp reovirus （GCRV） can cause fatal hemorrhagic disease in yearling populations. Until now, a s...Grass carp （Ctenopharyngodon idella） is an important species of freshwater aquaculture fish in China. However, grass carp reovirus （GCRV） can cause fatal hemorrhagic disease in yearling populations. Until now, a strategy to define the antigenic ca- pacity of the virus＇s structural proteins for preparing an effective vaccine has not been available. In this study, some sin- gle-chain variable fragment antibodies （scFv）, which could specifically recognize grass carp IgM, were selected from a con- structed mouse naive antibody phage display cDNA library. The identified scFv C1B3 clone was shown to possess relatively higher specific binding activity to grass carp IgM. Furthermore, ELISA analysis indicated that the IgM level in serum from vi- rus-infected grass carp was more than two times higher than that of the control group at 5-7 days post infection. Moreover, Western blot analysis demonstrated that the outer capsid protein VP7 has a specific immuno-binding-reaction with the serum IgM from virus-infected grass carp. Our results suggest that VP7 can induce a stronger immune response in grass carp than the other GCRV structural proteins, which implies that VP7 protein could be used as a preferred immunogen for vaccine design.展开更多
基金supported by the National Basic Research Program of China (2009CB118701,2009CB118704)the National Natural Science Foundation of China (31072233,31172434)
文摘Grass carp （Ctenopharyngodon idella） is an important species of freshwater aquaculture fish in China. However, grass carp reovirus （GCRV） can cause fatal hemorrhagic disease in yearling populations. Until now, a strategy to define the antigenic ca- pacity of the virus＇s structural proteins for preparing an effective vaccine has not been available. In this study, some sin- gle-chain variable fragment antibodies （scFv）, which could specifically recognize grass carp IgM, were selected from a con- structed mouse naive antibody phage display cDNA library. The identified scFv C1B3 clone was shown to possess relatively higher specific binding activity to grass carp IgM. Furthermore, ELISA analysis indicated that the IgM level in serum from vi- rus-infected grass carp was more than two times higher than that of the control group at 5-7 days post infection. Moreover, Western blot analysis demonstrated that the outer capsid protein VP7 has a specific immuno-binding-reaction with the serum IgM from virus-infected grass carp. Our results suggest that VP7 can induce a stronger immune response in grass carp than the other GCRV structural proteins, which implies that VP7 protein could be used as a preferred immunogen for vaccine design.
