日本血吸虫精氨酸酶编码基因cDNA的分离和序列分析

Isolation and Sequence Analysis of the cDNA Encoding Schistosoma japonicum Arginase

【目的】分离和鉴定日本血吸虫 (Schistosomajaponicum ,S .j)新基因。【方法】应用免疫学方法筛选S .jcDNA文库获得阳性克隆 ;通过PCR直接序列测定技术 ,表达序列标签 (EST)同源性检索对阳性克隆插入片段进行鉴定 ;采用亚克隆技术及生物信息学等技术 ,对获得的日本血吸虫精氨酸酶编码基因序列进行结构与功能的分析。【结果】获得了一个含10 6 1bp外源插入片段的阳性克隆 ,其cDNA序列含有一个 840bp的阅读框 ,编码 2 79个氨基酸 ,属精氨酸酶家族 ,与国际蛋白质库中的酵母、蛙、人和大鼠精氨酸酶序列的同源性分别为 44 % ,5 0 % ,5 1% ,5 3%和 5 4%。【结论】获得了编码日本血吸虫精氨酸酶编码基因全长cDNA ,为日本血吸虫精氨酸酶基因功能的研究奠定了基础。

Objectives To isolate and identify novel genes of Schistosoma japonicum(S.j) from cDNA library. Methods cDNA clones were screened from S.j cDNA library by immunological method, the inserts of positive cDNA clones were identified by PCR directed sequencing and homologous searching of EST, the cDNA sequence encoding S.j arginase was analyzed by the subcloning and bioinformatics. Results The positive cDNA clone with 1 061 bp insert was isolated from S.j cDNA library, which sequence of the insert included a ORF with 840 bp, and translated into 279 amino acid residues. The deduced protein was similar to the arginase family, the homology at amino acid sequence level was 44%,50%,51%,53% and 54% with schizosacch aromyces pombe (fission yeast) arginase, xenopus laevis (african clawed frog) arginase, homo sapiens (human) arginase ii precursor and rattus norvegicus (rat) arginase ii precursor respectively. Conclusion The full length cDNA sequence encoding Schistosoma japonicum arginase was cloned, which gave the basis for further studying of Schistosoma japonicum arginase.