猪囊尾蚴一种蛋白抗原的cDNA分子克隆

MOLECULAR CLONING OF A cDNA ENCODING AN ANTIGENIC POLYPEPTIDE OF CYSTICERCUS CELLULOSAE

目的 从猪囊尾蚴 c DNA文库中克隆某种编码蛋白抗原的基因。方法 用脑囊尾蚴病人血清筛选猪囊尾蚴 c DNA文库 ,获得阳性克隆后 ,经 PCR技术扩增噬菌体载体中插入的 c DNA片段 ,并将其亚克隆入 p U C18质粒载体中 ,用双脱氧核苷酸末端终止法测定插入片段的核苷酸序列。测序后与 Gen Bank中的核苷酸序列进行同源性分析。结果 经 3次筛选 ,从 c DNA文库中克隆出一个阳性克隆 ,测序后其长度为 5 4 6 bp,含有一个开放读码框 ,编码 15 8个氨基酸。同源序列分析结果表明此基因片段与编码猪囊尾蚴的一种免疫原性蛋白基因 (NC- 9)同源性高达 99%。

Objective To immunoscreen one protein antigen gene from a cDNA library of cysticercus cellulosae. Methods The cDNA library of cysticercus cellulosae was immunoscreened by using the serum of patient with cerebral cysticercosis. After the insert of positive clone was amplified by PCR and subcloned into pUC18, the nucleotide sequence of the cDNA was determined by the dideoxynucleotide chain termination method using a Taq DyeDeoxy Terminator Cycle Sequencing Kit. The homological search of the nucleotide sequence was done by using BLASTN in NCBI. Results A cDNA clone (named cY1) with a length of 546 bp was isolated. The clone contained one open reading frame composed of 474 bp encoding 158 amino acids. The nucleotide sequence of cY1 showed 99% homology with one immunogenic protein gene named NC-9 of cysticercus cellulosae. Conclusion A gene encoding protein antigen of cysticercus cellulosae is cloned.