Primary study on trans-activation ability of hepatitis B virus envelope proteins

目的构建系列含乙型肝炎病毒(HBV)表面抗原前-前-S区的酵母细胞表达质粒,初步探讨表达蛋白是否具有反式激活作用。方法用多聚酶链反应(PCR)扩增含前-前-S区的全S、S2和S基因,定向克隆于pDEST32载体,进行序列测定,重组质粒命名为pDEST32-wS、pDEST32-pS2和pDEST32-SHBs。用乙酸锂转化法将重组质粒转化酵母菌MaV203,经Western blot和胶体金法验证重组质粒在酵母细胞中的表达。以酵母双杂交法将重组质粒和载体pDEST22共同转入酵母菌MaV203,并在SC/-leu/-trp/-his三缺培养基及不同浓度梯度3AT培养基中验证自激活。结果重组质粒pDEST32-wS经序列测定含有HBV自前-前-S至主蛋白基因序列。经Western blot和胶体金法证实转染的酵母细胞可表达表面抗原蛋白。pDEST32-wS与pDEST22共转染实验证实被转染酵母细胞不能在浓度30 mmol/L以上的3AT培养基生存。结论构建了pDEST32-wS、pDEST32-pS2和pDEST32-SHBs表达载体,pDEST32-wS和pDEST32-SHBs在酵母细胞中可表达HBsAg... 【英文摘要】 Objective To construct yeast expression vector of HBV whole-S gene including pre-pre-S region and explore the trans-activation function of whole-S protein.Methods Whole-S gene,pre-pre-S to pre-S2 region and major HBsAg coding region containing Not I and Sal I endoenzyme sites were obtained by PCR method.After enzyme digestion,PCR products were cloned into yeast expression vector pDEST32.Recombinant plasmids were sequenced and named as pDEST32-wS,pDEST32-pS2 and pDEST32-SHBs,respectively.Recombinant plasmids...厦门市首批重大疾病科研攻关项目(WKZ0501);; 厦门市卫生局医学科研立项项目(WSK0506);; 厦门大学引进人才科研启动基金(Z03109);; 福建省青年科技人才创新项目(2006F3127);; 福建省青年科技人才创新项目(2006F3127

中国东南沿海港口外轮压舱水生物的调查

随机选取东南沿海港口的17艘外来船舶(含8条集装箱船和9条散货船)作为监测对象,进行压舱水浮游植物及动物的物种鉴定和丰度测定,并对监测数据进行统计学分析。检出分属于7个浮游植物门类和5个动物门类的309种外来压舱水生物(包括60种赤潮生物)。外轮压舱水生物的分布及生存状态与水样的水龄和盐度相关。船舶压舱水排放是大家熟知的外来水生生物入侵的主要媒介。本调查结果表明,中国东南沿海外来散货船的压舱水排放所具的潜在生物入侵风险比集装箱船更应受关注

A new mutation pattern of hepatitis B virus X gene

目的:证实乙型肝炎病毒(hepatitis Bvirus,HBV)X基因一种新的变异方式.方法:从HBV慢性感染患者血清中提取HBVDNA,扩增X基因序列,克隆入pMD19T载体,选择阳性克隆进行DNA测序,与已知HBV基因相应序列比较该患者体内HBV基因变异位点以及变异形式.结果:从21例患者中共挑选74个克隆测序,测序结果提示54个克隆X基因下游大段缺失突变,长度达234nt,位于1601-1834nt处,另有1个克隆发生245nt缺失突变.发生缺失变异的病毒株同时存在G/A1515C、G1518C和A1585T替换突变,这两种突变具有联动特征.缺失突变株HBx仅编码76aa,其第44和45位编码为LL,具有特异性.结论:观察到一种X蛋白变异方式,这种大段缺失突变导致X蛋白下游编码序列丢失,其为X因子还是X蛋白以及这种变异是否为常态形式尚需进一步研究.AIM: To identify a novel X gene mutation pattern of hepatitis B virus (HBV) in patients with chronic HBV infection.METHODS: A pair of primers was designed on the basis of nucleotide sequences of X gene. Polymerase chain reaction (PCR) was used to amplify the target region from HBV DNA sam- ples extracted from chronic hepatitis B patients in Xiamen city. After electrophoresis of the PCR products in 9 g/L agarose gel, the target regions were cut, re-purified and TA-cloned into pMD19 T vector. The inserted regions in positive clones were sequenced. Sequence comparison with HBV genome submitted in GenBank was made to find the mutation sites. RESULTS: Totally 74 strains from 21 patients with chronic HBV infection were sequenced, and the results showed that there was a charac- teristic deletion region, with a length of 234 nt (nt 1601-1834) in 54 clones, and a length of 245 nt in 1 clone. There were 3 replacement mutations bounding to deletion mutation: G/A1515C, G1518C and A1585T, which caused substitutions in the 44th and 45th amino acid site to LL. These mutant strains only coded 76 aa of up-stream HBx. CONCLUSION: A novel deletion mutation in HBV X gene is observed in patients with chronic HBV infection. The deletion mutants encode 76-aa X factor instead of X protein.厦门市首批重大疾病科研攻关资助项目,No.WKZ0501;; 厦门市卫生局医学科研立项资助项目,No.WSK0506;; 厦门大学引进人才科研启动基金资助项目,No.Z03109;; 福建省青年科技人才创新资助项目,No.2006F3127~

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies