幽门螺杆菌napA基因的克隆及生物信息学分析

目的]获取幽门螺杆菌NCTC11639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，为耶疫苗研制奠定基础。方法]提取幽门螺杆菌标准株NCTC11639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，在不同耶菌株中高度保守，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。

CLONE AND BIOINFORMATION ANALYSIS OF napA GENE OF HELICOBACTER PYLORI

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 Hp 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.