中文摘要：

选择家蚕微孢子虫（Nosema bombycis）表面蛋白质谱数据库中新发现的假定表面蛋白NBO_33g0013进行研究,了解该蛋白质的功能及是否参与微孢子虫对宿主细胞的侵染过程。预测该蛋白质分子质量为26.1 k D,等电点为4.59,其序列N端具有信号肽,无跨膜螺旋结构,含3个N-糖基化位点,无O-糖基化位点,不具有典型的功能结构域,与柑橘凤蝶微孢子虫（Papilio xuthus）的一个假定蛋白序列相似度达到93%。以家蚕微孢子虫CQ1分离株的基因组DNA为模板克隆该蛋白质的编码基因,构建重组表达载体进行该蛋白质的原核表达,并制备获得多克隆抗体,通过间接免疫荧光分析确证该蛋白质定位在家蚕微孢子虫孢子表面。经体外细胞感染实验初步分析,尚未发现该蛋白质参与了微孢子虫孢子对宿主Bm E细胞的粘附过程,推测该蛋白质可能为家蚕微孢子虫孢壁的结构组成型蛋白质,在孢壁的构架形成中发挥作用。

英文摘要：

NBO_33g0013, a novel putative surface protein deposited in mass spectrometry database of Nosema bombycis surface proteins, was investigated to understand its function and whether it is involved in the infection to host cells. This protein is predicted to have a molecular weight of 26. 1 kD, a theoretical pl value of 4.59, a signal peptide at N-terminus, and three N-glycosylation sites. It has no O-glycosylation site and no typified functional domain. It has 93% sequence identity with a hypothetical protein from Papilio xuthus. Coding gene of this protein was cloned using genomic DNA of N. bombycis isolate CQ1 as template. Its recombinant protein was expressed in prokaryotic cells and used to prepare polyclonal antibody. Indirect immunofiuorescence analysis revealed that this protein was localized on the surface of N. bombycis spore. In vitro infection analysis displayed that this protein was not involved in the process of adhesion between microsporidian spore and BmE cell. These data suggest that this protein may be an important structural protein in maintaining the integrity of N. bombycis spore wall.