幽门螺杆菌napA基因的克隆及生物信息学分析

CLONE AND BIOINFORMATION ANALYSIS OF napA GENE OF HELICOBACTER PYLORI

[目的]获取幽门螺杆菌NCTC 11639中性粒细胞激活蛋白基因(napA),预测其编码蛋白作为幽门螺杆菌疫苗候选抗原的可行性,为Hp疫苗研制奠定基础。[方法]提取幽门螺杆菌标准株NCTC 11639的基因组DNA,参照GeneBank中幽门螺杆菌标准株22695的序列设计引物PCR扩增napA基因,克隆入pMD18-T载体中,对重组质粒测序后进行生物信息学分析。[结果]克隆的napA基因全长为435bp,在GenBank上登录(No.DQ341279),与Gen-Bank公布的其它Hp菌株的核酸同源性为94%～98%,与国际测序模式株Hp26695、HpJ99同源性达97%。[结论]成功扩增Hp标准株NCTC 11639 napA基因,通过同源性检索分析表明Hp与人及其它哺乳动物的基因组DNA同源序列低,在不同Hp菌株中高度保守,符合疫苗候选抗原的基本特征;抗原表位预测显示有4条高抗原性肽段,其中118-140肽段抗原指数最强,可能存在良好的抗原表位,结合Hp-NAP二级结构、亲水性分析认为Hp-NAP是很有前景的幽门螺杆菌疫苗候选抗原。

[Objective] To amplify Helicobacter pylori （Hp） neutrophil-activating protein gene （napA） by PCR, analyze nucleic acid sequence and their features to predict the possibilities for it to be a potential vaccine. [Methods] napA fragment was amplified from Hp NCTC11639 chromosomal DNA by PCR .Its T-A was cloned, sequenced and compared with other Hp strains in the GenBank. The sequences of napA genes were analyzed by bioinformatic software. [Results] napA fragment was composed of 435 base pairs （GenBank No. DQ341279） and the nucleotide homology with other lip strains on the GenBank was 94%-98%. [Conclusion] The protein has significant antigenicity, and their homology is low compared with other species, which suggests that the protein NAP is a hot-prospect vaccine candidate of Hp.