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目的 筛选和分析日本血吸虫 (Schistosomajaponicum ,Sj)新基因 ,为血吸虫疫苗研究提供新的候选分子。 方法 以日本血吸虫雄性成虫抗原免疫兔血清为探针 ,筛选Sj成虫cDNA文库 ,对阳性克隆的插入片段进行PCR鉴定及测序分析。通过互联网对测序获得的核苷酸序列进行同源性分析 ,并预测新基因编码蛋白的结构与功能。结果 筛选获 11个阳性克隆 ,其插入SjcDNA片段大小在 0 7～ 2 3kb之间。对部分阳性克隆进行测序分析 ,获两个Sj新基因 ,即Sj-MA及Sj -Cp8(登录号分别为AF5 1980 8和AF5 2 4 896 ) ,分别编码 2 4 9和 71个氨基酸的核内蛋白和胞浆蛋白。Sj-MA蛋白含有 9个蛋白激酶C磷酸化位点、3个酪蛋白激酶Ⅱ磷酸化位点、2个酪氨酸激酶磷酸化位点和 1个N -肉豆蔻酸化位点。Sj-Cp8蛋白含一个跨膜区、3个酪蛋白激酶Ⅱ磷酸化位点、2个N -肉豆蔻酸化位点。结论 筛选Sj成虫cDNA文库所获得两个新基因 ,其编码的蛋白可能为存在于胞浆和胞核内的日本血吸虫的重要信息传递分子 ,有望成为新的血吸虫病疫苗候选分子。
Objective To screen and analyze the new gene of Schistosoma japonicum (Sj), and to provide a new candidate for schistosoma vaccine research. Methods The Sj adult worm cDNA library was screened with the serum of rabbits immunized with the adult male adult antigen of Schistosoma japonicum, and the inserted fragment of the positive clone was identified by PCR and sequenced. Homology analysis of the nucleotide sequences obtained by sequencing was made through the Internet and the structure and function of the new gene encoding protein were predicted. Results A total of 11 positive clones were screened and inserted into SjcDNA fragments between 0 7 and 23 kb in size. Two of the new Sj genes, namely Sj-MA and Sj-Cp8 (accession numbers AF5 1980 8 and AF5 2 4 896 respectively) were obtained by sequencing positive clones, encoding 299 nucleotides and 71 amino acids respectively Protein and cytoplasmic proteins. The Sj-MA protein contains 9 protein kinase C phosphorylation sites, 3 casein kinase II phosphorylation sites, two tyrosine kinase phosphorylation sites and one N-myristoylation site. The Sj-Cp8 protein contains a transmembrane region, three casein kinase II phosphorylation sites and two N-myristoylation sites. Conclusions Two novel genes obtained from Sj adult cDNA library are screened and their proteins may be important information transduction molecules of Schistosoma japonicum present in the cytoplasm and nucleus, which may be expected as a new vaccine candidate for schistosomiasis.