旋毛虫ES抗原特异性蛋白两个结构基因的序列分析及重组质粒的构建

目的：获取旋毛虫ＥＳ抗原的结构基因，对其鉴定和克隆，并研制旋毛虫基因重组抗原。方法：先用反转录ＰＣＲ技术获取目的基因，经序列测定和酶切分析后，再用重组ＤＮＡ技术分别将目的基因与融合表达载体ｐＥＸ３１Ｃ、ｐＥＸ３１Ｂ及表达载体ｐＢＶ２２０连接，评价在大肠杆菌中的表达效果和鉴定表达产物的特异性。结果：获得了编码ＥＳ抗原特异性蛋白成分的两个结构基因（０．７ｋｂ和０．９５ｋｂ），其序列与文献报道的稍有差异。共构建３个重组质粒并在大肠杆菌中表达出相应分子量大小的重组蛋白，均能被猪旋毛虫病阳性血清所识别，但非融合蛋白的特异性强于融合蛋白。在相同条件下，融合蛋白的表达量高于非融合蛋白，而表达蛋白的分子量大小与表达水平呈负相关性。结论：在大肠杆菌中表达的３种重组蛋白是研制旋毛虫基因重组抗原的良好候选抗原蛋白。     

日本血吸虫酪氨酸羟化酶基因的克隆、真核表达及鉴定

目的扩增日本血吸虫的酪氨酸羟化酶（Schistosoma japonicum Tyrosine Hydroxylase,SjTH）编码基因,构建pcDNA3.1(+) SjTH真核表达载体,并检测其在COS 7细胞中的表达情况。方法以日本血吸虫成虫cDNA为模板,RACE PCR扩增SjTH编码基因,并与pGEM T连接进行亚克隆,双酶切后回收目的基因,并与真核表达载体pcDNA3.1(+)连接,PCR和双酶切初步鉴定后测序,纯化无内毒素重组质粒pcDNA3.1(+) SjTH,转染入COS 7细胞,G418筛选阳性克隆,RT PCR和Western blot鉴定重组SjTH蛋白的表达。结果RACE PCR 扩增出SjTH编码基因,大小约1 392bp,经双酶切鉴定、测序及Blast分析鉴定重组真核质粒构建成功。脂质体介导无内毒重组真核质粒pcDNA3.1(+) SjTH转染入COS 7细胞,G418筛选出阳性克隆,RT PCR证实阳性单克隆细胞带有SjTH编码基因,Western blot鉴定单克隆细胞表达重组SjTH蛋白,大小约54kD。结论真核表达载体pcDNA3.1(+) SjTH构建成功,G418筛选出阳性克隆,真核表达重组SjTH蛋白,为后续研究SjTH蛋白功能奠定基础。     

日本血吸虫分泌蛋白基因Sjsp16的克隆与表达

目的　克隆和表达日本血吸虫新的分泌蛋白Sjsp16的编码基因。　 方法　根据EST测序的结果设计引物 ,从含有Sjsp16基因的cDNA克隆中扩增得到该编码基因 ,亚克隆入原核表达载体 pET2 8中表达 ,然后用生物信息学的方法对蛋白结构功能进行预测。　结果　成功克隆和表达了日本血吸虫分泌蛋白基因Sjsp16,生物信息学分析提示该基因编码蛋白的N端带有一个信号肽序列 ,是一个分泌蛋白 ,含有一个ML功能结构域 ,具有 4种潜在的功能作用位点 ,即 1个N 糖基化位点、3个蛋白激酶C磷酸化位点、4个酪蛋白激酶Ⅱ磷酸化位点和 3个肉豆蔻酰化位点。　结论　Sjsp16基因编码蛋白为具有脂质识别和结合功能的分泌蛋白 ,可能为潜在的血吸虫病药物靶点或疫苗候选分子。     

间日疟原虫MSP1C端基因亚克隆及在肠埃希菌中的融合表达

目的　在大肠埃希菌中融合表达间日疟原虫MSP1C端编码基因 ,以获得能作为检测抗原的重组蛋白GST PvMSP1C。　方法　以限制性内切酶BamHⅠ和SalⅠ双酶切质粒pMD/PvMSP1C ,获得间日疟原虫MSP1C端编码基因片段 ,柱纯化后 ,插入表达质粒载体的多克隆位点 ,构建重组体 pGEX 4T 2 /PvMSP1C ,并转化大肠埃希菌BL2 1(DE3 ) ,阳性克隆以限制性酶切分析鉴定后 ,以IPTG进行诱导表达 ,表达产物以SDS PAGE电泳与免疫印迹分析。　结果　双酶切质粒pMD/PvMSP1C ,获得 1119bp的PvMSP1C编码基因片段 ,与预期片段大小相符 ;所构建的 pGEX 4T 2 /PvMSP1C重组体阳性克隆经双酶切鉴定与预期结果一致 ;SDS PAGE电泳显示 ,GST PvMSP1C融合表达蛋白的大小约 63ku ,且能够分别被GST抗体与间日疟患者的血清所识别。　结论　成功亚克隆并构建了间日疟原虫MSP1C端编码基因 pGEX 4T 2 /PvMSP1C表达质粒 ,诱导表达了GST PvMSP1C融合蛋白 ,表达蛋白具有一定免疫活性。     

乙型脑炎病毒非结构4A蛋白编码基因重组子的构建及表达

目的构建流行性乙型脑炎病毒(JEV)非结构4A(NS4A)蛋白编码基因重组子并鉴定。方法以JEV SA14-14-2株Total RNA为模板,运用RT-PCR方法扩增JEV NS4A蛋白编码基因,克隆至pMD19-T Simple载体并测序。为便于分析JEV NS4A蛋白编码基因重组子在哺乳动物细胞中的表达,在JEV NS4A蛋白编码基因5’端附加FLAG序列,亚克隆至pcDNA3.1(+)载体中,构建重组子pJNS4A并作酶切及DNA测序分析;采用脂质体法将pJNS4A转染中华仓鼠卵巢(CHO)细胞,采用免疫荧光法检测转染的CHO细胞中JEV NS4A蛋白分布与表达。结果重组质粒pJNS4A经BamHⅠ/EcoRⅠ酶切释出的插入子在830bp左右,与JEV NS4A蛋白编码基因和FLAG基因序列之和(834bp)相一致。JEV NS4A蛋白编码基因重组质粒转染的CHO细胞可见绿色荧光标记,主要分布在胞膜。结论 pJNS4A构建成功,转染的CHO细胞可稳定表达JEV NS4A蛋白。     

弓形虫表面抗原P22编码基因片段的亚克隆与表达

目的亚克隆弓形虫RH株表面抗原P22编码基因,构建表达质粒pBK/P22,并对其在大肠杆菌(E.coli)中的表达作初步研究. 方法以限制性内切酶BamHⅠ和KpnⅠ双酶切质粒pBCG5.6/P22,获得弓形虫表面抗原P22编码基因目的片段,在以低熔点琼脂糖回收纯化后,插入表达质粒载体pBK-CMV的多克隆位点,构建重组体pBK/P22,并转化大肠杆菌DH 5α,快速酚法初筛阳性重组子,阳性克隆以PCR法与限制性酶切分析鉴定后,以IPTG进行诱导在E.coli DH 5α中表达,表达产物以SDS-PAGE与免疫印迹分析. 结果双酶切质粒pBCG5.6/P22,获得约593 bp的P22编码基因片段,与预期片段大小相符;所构建pBK/P22重组体阳性克隆经双酶切和PCR鉴定与预期结果一致;SDS-PAGE与免疫印迹显示,表达产物的大小约28 ku. 结论成功亚克隆并构建了弓形虫表面抗原P22编码基因pBK/P22表达质粒,诱导表达了弓形虫P22表面抗原蛋白,为抗原免疫特性的研究奠定了基础.     

亚马逊利什曼原虫无鞭毛体蛋白基因的克隆化与序列分析

目的：克隆亚马逊利什曼原虫（L.ama)无鞭毛蛋白（amastin)的编码基因,并对其同源基因序列进行分析,方法：根据我们首次克隆的硕大利什曼原虫（L.major)无鞭毛体蛋白的编码基因,设计并合成核苷酸序列特异性引物,以亚马逊利什曼原虫基因组DNA为模板,以多聚酶链反应PCR技术扩增无鞭毛体的编码基因DNA片段,并进行核苷酸 列测定以及核苷酸序列的同源性分析。结果：克隆了亚马逊利什曼原虫无鞭毛体蛋白的编码基因,含有单一开放读框,长度为552bp,编码的无鞭毛体蛋白由183个氨基酸残基（aa)组成,亚马逊利什曼原虫与硕大利什曼原虫无鞭毛体蛋白编码基因之间高度同源,在核苷酸与氨基酸残基序列水平上的同源性分别为96％和94％,结论：首次实现亚马逊利什曼原虫无鞭毛体蛋白基因的克隆化。     

幽门螺杆菌基因hpaA克隆、融合表达和鉴定

目的克隆幽门螺杆菌粘附素基因hpaA,构建幽门螺杆菌hpaA基因与麦芽糖结合蛋白基因融合表达载体,并进行诱导表达,鉴定融合蛋白免疫原性,为幽门螺杆菌疫苗研究提供依据。方法利用PCR技术从H.pylori郑州分离株MEL-HP27染色体DNA上扩增出hpaA基因,序列分析后,将其克隆到表达载体pMAL-c2X中,转化大肠杆菌(E.coliTB1),用IPTG诱导目的基因表达,SDS-PAGE方法对表达产物进行分析,Western blot鉴定其免疫原性。结果用PCR方法扩增的hpaA基因长度为783bp,编码260个氨基酸,经酶切鉴定和测序,插入到克隆载体的基因片段与预期目的DNA片段相一致;SDS-PAGE结果显示表达产物相对分子质量约为29kDa,融合蛋白的表达量约占全菌总蛋白的26%。结论本研究成功构建了hpaA基因与麦芽糖结合蛋白基因融合原核表达系统,为幽门螺杆菌基因工程组分疫苗的研究奠定基础。     

间日疟原虫MSP1 C端基因亚克隆及在大肠埃希菌中的融合表达

目的 在大肠埃希菌中融合表达间日疟原虫MSP1 C端编码基因，以获得能作为检测抗原的重组蛋白GSTPvMSP1 C。方法 以限制性内切酶BamH Ⅰ和Sal Ⅰ双酶切质粒pMD／PvMSP1C，获得间日疟原虫MSP1 C端编码基因片段．柱纯化后，插入表达质粒载体的多克隆位点，构建重组体pGEX-4T-2／PvMSP1C，并转化大肠埃希菌BL21(DE3)，阳性克隆以限制性酶切分析鉴定后，以IPTG进行诱导表达，表达产物以SDS-PAGE电泳与免疫印迹分析。结果 双酶切质粒pMD／PvMSP1C，获得1 119bp的PvMSP1 C编码基因片段，与预期片段大小相符；所构建的pGEX-4T-2／PvMSP1C重组体阳性克隆经双酶切鉴定与预期结果一致；SDS-PAGE电泳显示，GST-PvMSP1C融合表达蛋白的大小约63 ku，且能够分别被GST抗体与间日疟患者的血清所识别。结论 成功亚克隆并构建了间日疟原虫MSP1 C端编码基因pGEX-4T-2／PvMsP1C表达质粒，诱导表达了GST-PvMSP1C融合蛋白，表达蛋白具有一定免疫活性。     

幽门螺杆菌尿素通道蛋白基因Urel的真核载体构建、表达及抗原性研究

目的构建含人幽门螺杆菌（Helicobacter pylori,H．pylori）尿素通道蛋白编码基因（UreI）的真核表达的重组载体,并在COS-7细胞中表达,为核酸疫苗的开发奠定基础。方法以原核表达质粒pET32a（＋）／UreI为模板,扩增UreI编码基因片段,将目的基因与同样进行酶切、纯化的载体pEGFPN1进行连接,而后转化并筛选含有目的基因的重组载体pEG—FP—N1／UreI,并在COS-7细胞中表达,以荧光蛋白和Westernblot法检测其表达产物。结果经酶切、测序证实插入的基因片段为H．pyloriUreI蛋白编码基因;荧光显微镜下和Westernblot法等检测显示,该重组质粒能够在COS-7细胞中表达目的蛋白,同时能够被H．pylori阳性患者血清所识别。结论成功地构建了真核重组载体pEGFP—N1／UreI,并在COS-7细胞中表达。     

幽门螺杆菌抗原基因ureB在乳酸菌中的克隆表达与免疫反应性研究

目的为了开发幽门螺杆菌（Helicobacter pylori,Hp）口服疫苗,将Hp尿素酶B（UreB）在食品级乳酸乳球菌NZ3900菌株中进行表达,并研究其免疫反应性。方法 PCR扩增Hp MEL-HP27菌株ureB基因（基因号：FJ436980）,将其克隆入大肠杆菌-乳酸乳球菌穿梭质粒pNZ8110中并转化乳酸乳球菌NZ3900;采用正交试验确定目的蛋白表达的适宜条件;应用western-blot鉴定其免疫反应性。结果成功扩增了Hp MEL-HP27菌株ureB基因,构建了ureB基因的乳酸菌NICE（Nisin-controlled expression）原核表达系统;UreB蛋白适宜的表达条件为：在ureB重组菌生长至对数生长前期（OD600≈0.3～0.4）加入终浓度为40ng/mL的nisin,诱导表达5h,可溶性UreB蛋白表达量最高,可达27.26μg/mL培养基。可溶性UreB蛋白的表达占上清蛋白的比例最高可达20.19%;Western-blot结果显示乳酸乳球菌表达的UreB抗原蛋白具有良好的免疫反应性。结论结果提示应用乳酸乳球菌构建幽门螺杆菌食品级疫苗可能具有较好前景。     

幽门螺杆菌双亚单位表位疫苗的构建及免疫原性研究

目的构建幽门螺杆菌(Helicobacter pylori,Hp)黏附素(HpaA)和尿素酶B亚单位(UreB)双亚基多表位疫苗,并对其免疫原性进行研究。方法设计引物采用PCR法将黏附素(HpaA)的一个B细胞表位与尿素酶B亚单位的三个TH表位及一个B细胞表位串联起来(HUepi),表位之间用两个赖氨酸(KK)间隔,T-A克隆后构建融合基因表达质粒pET-22b( )-HUepi,在大肠杆菌BL21(DE3)中表达,重组蛋白采用阳离子和疏水层析进行纯化,经鉴定后皮下免疫BALB/c小鼠,检测细胞免疫应答及体液免疫应答。结果PCR法扩增出了约233bp的目的片段;原核表达质粒pET-22b( )-HUepi经酶切及测序鉴定,目的基因序列与设计序列一致;重组蛋白HUepi表达率约20.0%,PAGE初步测定目的蛋白的相对分子质量(Mr)约8.38×103Dr,破菌后电泳证实目的蛋白以可溶形式表达,纯化后蛋白纯度大于97.6%,经N端测序证实为设计的表位疫苗蛋白,TH表位多肽、表位疫苗蛋白及rUreB均能够刺激表位疫苗致敏的小鼠淋巴细胞增殖(SI>2),并且此疫苗能够刺激机体产生特异性抗体。结论Hp HpaA、UreB双亚基表位疫苗HUepi经基因克隆获得了较高的表达量,并初步显示了较好的免疫原性。为新一代Hp疫苗的研制奠定实验基础。     

Construction of prokaryotic expression system of ureB gene from a clinical Helicobacter pylori strain and identification of the recombinant protein immunity

AIM: To clone ureB gene from a clinical isolate of Helicobacter pyloriand construct a prokaryotic expression system of the gene and identify immunity of the expressed recombinant protein. METHODS: ureBgene from a clinical Hpyloristrain Y06 was amplified by the high fidelity polymerase chain reaction technique. The target DNA fragment amplified from ureB gene was sequenced after T-A cloning. Prokaryotic recombinant expression vector pET32a inserted with ureB gene (pET32a-ureB) was constructed. The expression of recombinant UreB protein (rUreB) in E. coli BL21DE3 induced by isopropylthio-β-D-galactoside (IPTG) at different concentrations was examined by SDS-PAGE. Western blot using commercial antibodies against whole cell of Hpylori and an immunodiffusion assay using a self-prepared rabbit anti-rUreB antibody were applied to determine immunity of the target recombinant protein. ELISA was used to detect the antibody against rUreB in sera of 125 Hpyloriinfected patients and to examine rUreB expression in 109 Hpylori isolates. RESULTS: In comparison with the reported corresponding sequences, the nucleotide sequence homology of the cloned ureB gene was from 96.88-97.82% while the homology of its putative amino acid sequence was as high as 99.65-99.82%. The rUreB output expressed by pET32a-ureB-BL21DE3 was approximate 30% of the total bacterial proteins, rUreB specifically combined with the commercial antibodies against whole cell of Hpylori and strongly induced rabbits to produce antibody with a 1:8 immunodiffusion titer after the animals were immunized with the recombinant protein. Serum samples from all Hpyloriinfected patients were positive for UreB antibody and UreB expression were detectable in all tested Hpyloriisolates. CONCLUSION: A prokaryotic expression system with high expression efficiency of Hpylori ureBgene was successfully established. The expressed rUreB showed qualified immunoreactivity and antigenicity. High frequencies of UreB expression in different Hpyloriisolates and specific antibody against UreBin sera of Hpyloriinfected patients indicatet hat UreB is an excellent antigen candidate for developing H pylori vaccine.     

表达幽门螺杆菌尿素酶B亚单位的减毒鼠伤寒杆菌口服疫苗的制备

目的制备抗幽门螺杆菌(Hp)尿素酶B亚单位(UreB)减毒鼠伤寒杆菌活菌疫苗,观察其免疫效果.方法构建表达UreB的原核表达载体PTc01-UreB并转化减毒鼠伤寒杆菌SL3261,得到重组菌SL3261/PTc01-UreB.应用抗Hp菌体蛋白兔血清行Western-blot检测UreB在SL3261中的表达.将SL3261/PTc01-UreB口服免疫Balb/c小鼠,12周后应用ELISA检测肠液和血清中的特异性抗体反应.SL3261/PTc01-UreB在Luria-Bertani培养液中连续传代60代以确定其稳定性.结果成功构建PTc01-UreB原核表达载体.Western-blot显示,其转化减毒鼠伤寒杆菌SL3261后能表达相对分子质量约61×103的蛋白,与HpUreB亚单位相符,具有抗原性.口服免疫小鼠后,在肠液和血清中可分别检测到针对UreB的特异性IgA和IgG抗体.体外连续培养60代未见PTc01-UreB质粒丢失及对宿主细胞毒性.结论表达HpUreB的减毒鼠伤寒杆菌SL3261/PTc01-UreB可用作抗Hp感染口服疫苗.     

日本血吸虫中国大陆株基因重组抗原Sj 22.6kDa的核苷酸序列分析

目的：对ｐＧＳｊ２４克隆化基因进行核苷酸序列分析，了解其编码蛋白的属性。方法：常规制备ｐＧＳｊ２４克隆化基因并重组入测序载体Ｍ１３ｍｐ１９，以ＤＹＥＰＲＩＭＥＲ荧光测序试剂盒进行核苷酸序列测定。分别以ＤＮＡＳＩＳ和ＧＯＬＤＫＥＹ软件对序列资料进行分析。结果：ｐＧＳｊ２４克隆化基因长８４０ｂｐ，含一开放阅读框，可编码一分子量为２２．６ｋＤａ的蛋白质。开读框上游和下游均有终止密码子。该基因与已发表的日本血吸虫２２．６ｋＤａ蛋白的编码基因同源性达９５％，编码区同源性达９９．７％。在该基因内有一段典型的ＥＦ－Ｈａｎｄ钙结合区序列，并有内质网导肽、微体导向信号等功能位点。预测该蛋白质内可能的抗原决定簇位置为第２９－３２、６３－６８和８７－１０１等氨基酸片段。结论：ｐＧＳｊ２４克隆化基因为日本血吸虫２２．６ｋＤａ抗原编码基因。     

Human T-cell growth factor: partial amino acid sequence, cDNA cloning, and organization and expression in normal and leukemic cells.

The partial amino acid sequences of human T-cell growth factors (TCGFs) isolated from normal peripheral blood lymphocytes and from a leukemia T-cell line (Jurkat) show that the amino-terminal sequences of the two proteins (15 residues) are identical. Oligonucleotides based on the published Jurkat TCGF DNA sequence were used to isolate six cDNA clones of TCGF mRNA from normal lymphocytes. The predicted amino acid sequence of normal lymphocyte TCGF was identical to the sequence of the Jurkat protein, showing that the differences in biochemical properties of the two proteins result from post-translational events. Amino acid and nucleotide sequence data suggest that TCGF is derived from a precursor polypeptide that is cleaved at the amino terminus but not at the carboxyl terminus. Hybridization of the cloned lymphocyte TCGF cDNA to cellular DNA and RNA strongly suggested that the TCGF gene is expressed as a single mRNA species from a single-copy gene. No differences in the organization of the TCGF gene in normal, leukemic, and human T-cell leukemia/lymphoma virus-infected cells was detected regardless of whether they produce TCGF or not.     

幽门螺杆菌IgG抗体组分与冠心病发病的相关性研究

目的　探讨幽门螺杆菌 (H·pylori,下称Hp)IgG抗体及其抗体组分与冠心病发病的相关性。方法　2 0 0 1- 0 3～ 2 0 0 3- 0 9广东佛山市第一人民医院应用免疫印迹法检测了 2 0 9例冠心病患者和 191名健康者的Hp血清特异性IgG抗体及其抗体组分。结果　冠心病患者Hp抗体的阳性率显著高于正常对照组 (P =0 . 0 0 4 2 )。用免疫印迹法对Hp抗体组分分析显示 :Hp抗体具有抗细胞毒素相关基因A(CagA)、空泡毒素蛋白A(VacA)、尿素酶A(UreA)、尿素酶B(UreB)等不同的抗体组分 ,仅抗体组分UreB6 6的阳性率在冠心病组 (46 % )与正常对照组(28% )之间有显著差异 (P =0 . 0 0 0 1)。非条件多元逐步Logistic回归分析显示冠心病与UreB6 6、总胆固醇 (TCH)及低密度脂蛋白 -胆固醇 (LDL)显著正相关 ,与高密度脂蛋白 -胆固醇 (HDL)显著负相关 (P <0 . 0 5 )。结论　冠心病发病与Hp感染有关 ,与抗体组分UreB6 6密切相关 ,而含有CagA或VacA抗原成分、在消化系统具有强致病作用的Hp强毒力菌株并无较强的致冠心病作用 ,Hp感染引起冠心病的发病可能通过免疫途径实现。     

日本血吸虫中国大陆株基因重组抗原Sj 22.6kDa的核苷酸序列分析

目的：对ｐＧＳｊ２４克隆化基因进行核苷酸序列分析，了解其编码蛋白的属性。方法：常规制备ｐＧＳｊ２４克隆化基因并重组入测序载体Ｍ１３ｍｐ１９，以ＤＹＥＰＲＩＭＥＲ荧光测序试剂盒进行核苷酸序列测定。分别以ＤＮＡＳＩＳ和ＧＯＬＤＫＥＹ软件对序列资料进行分析。结果：ｐＧＳｊ２４克隆化基因长８４０ｂｐ，含一开放阅读框，可编码一分子量为２２．６ｋＤａ的蛋白质。开读框上游和下游均有终止密码子。该基因与已发表的日本血吸虫２２．６ｋＤａ蛋白的编码基因同源性达９５％，编码区同源性达９９．７％。在该基因内有一段典型的ＥＦ－Ｈａｎｄ钙结合区序列，并有内质网导肽、微体导向信号等功能位点。预测该蛋白质内可能的抗原决定簇位置为第２９－３２、６３－６８和８７－１０１等氨基酸片段。结论：ｐＧＳｊ２４克隆化基因为日本血吸虫２２．６ｋＤａ抗原编码基因。     

Cloning, nucleotide sequence, and overexpression of the bacteriophage T4 regA gene.

The bacteriophage T4 regA gene codes for a regulatory protein that controls the expression of a number of T4 early genes, apparently at the level of translation. Restriction fragments containing the regA structural gene have been cloned into phage M13, and the nucleotide sequence has been determined. Translation of the DNA sequence predicted that regA protein contains 122 amino acids, with a Mr of 14,620. A DNA fragment carrying 85% of the coding sequence of regA has been cloned into the phage lambda leftward promoter PL expression vector pAS1, and a high level of truncated regA protein was produced by nalidixic acid induction. Protein chemical studies of the truncated regA protein gave results consistent with the nucleotide sequence of the regA gene. Subsequently, an intact regA gene was cloned into plasmid pAS1 and overexpressed. The regA protein produced in this way regulates the level of T4 45 and 44 proteins when their corresponding genes are carried on the same plasmid as the regA gene.     

A study of recombinant protective H.pylori antigens

AIM: To construct a recombinant vector which can express M (r)26000 outer membrane protein (OMP) from Helicobacter pylori (Hp), and to obtain the vaccine protecting against Hp infection and a diagnostic reagent kit quickly detecting Hp infection. METHODS: The gene encoding the structural M(r)26000 outer membrane protein of Hp was amplified from Hp chromosomal DNA by PCR, and inserted in the prokaryotic expression vector pET32a (+), which was transformed into the Top10 E. coli strain. Recombinant vector was selected, identified and transformed into BL-21(DE3) E. coli strain. The recombinant fusion proteins were expressed. The antigenicity of recombinant protein was studied by ELISA or immunoblotting and immunized Balb/c mice. RESULTS: The gene of M(r)26000 OMP was amplified to be 594 base pairs, 1.1% of the cloned genes was mutated and 1.51% of amino acid residues was changed, but there was homogeneity between them. The recombinant fusion protein encoded objective polypeptides of 198 amino acid residues, corresponding to calculated molecular masses of M (r)26000. The level of soluble expression products was about 38.96% of the total cell protein. After purification by Ni-NTA agarose resin columniation, the purity of objective protein became about 90%. The ELISA results showed that recombinant fusion protein could be recognized by patient serum infected with Hp and rabbit serum immunized with the recombinant protein. Furthermore,Balb/c mice immunized with the recombinant protein were protected against H.pylori infection. CONCLUSION: M (r)26000 OMP may be a candidate vaccine preventing Hp infection.