日本血吸虫丝氨酸蛋白酶抑制剂基因的克隆和分析

为筛选新的有潜在保护性的抗原分子编码基因 ,采用重复感染兔血清免疫筛选日本血吸虫成虫cDNA文库 ,将阳性克隆的插入序列进行了PCR扩增和序列分析。结果发现 ,所筛选的阳性克隆中有 2个为日本血吸虫丝氨酸蛋白酶抑制剂基因 (SPI)。序列分析表明 ,它可编码分子质量为 4 .6ku ,等电点为 5 .76的蛋白 ,与GenBank中日本血吸虫SPI基因 (大陆株 )、曼氏血吸虫SPI基因和埃及血吸虫SPI基因编码的氨基酸序列的同源性分别为 98%、6 2 %和 6 2 %。TMpred分析表明 ,该蛋白具有 2个明显的跨膜区即 36～ 5 5和 35 6～ 372位氨基酸。

Cloning and sequence analysis of serpin gene of Schistosoma japonicum

To obtain genes encoding potential protective antigens, Schistosoma japonicum adult worm cDNA library was immunoscreened with sera from rabbits repeatedly infected with Schistosoma japonicum. The inserting sequence of positive clone was amplified by PCR and sequenced.The obtained data were analyzed with Nucleotide BLAST software of NCBI and Export Protein Analysis of Swiss Institute of Bioinformatics. The Schistosoma japonicum serpin gene was obtained,which has 1016 bases encoding a protein with372amino acides,PI 5.76 and MW 4.6 ku. The amino acid sequence homology were 98% with that of Schistosoma japonicum mailand strain, 62%and 62% with that of Schistosoma haematobium and Schistosoma mansoni respectively. TMpred analysis showed the protein has 2 strong transmembrane helices.