花生主要变应原Ara h2的克隆及原核表达

目的:在原核载体中克隆、表达花生主要变应原Ara h2,为其重组变应原应用研究奠定基础。方法:合成花生主要变应原Ara h2基因,设计特异性引物行PCR扩增,经Eco RⅠ、HindⅢ双酶切后与做相应酶切的pET-28a载体连接,转化大肠杆菌BL21,提取质粒进行双酶切鉴定及测序分析,使用IPTG诱导融合蛋白表达,使用Ara h2特异性多克隆抗体对表达产物进行免疫印迹鉴定。结果:成功扩增了Ara h2基因,重组质粒双酶切见目的条带,基因测序显示Ara h2在正确开放阅读框中,基因长423bp,编码140个氨基酸,预测的等电点为5.3,分子量约16660.17 Da,基因比对分析显示其与相关报道的核苷酸序列一致性达100%。重组pET-28a-Ara h2/BL21经0.6 mmol/L IPTG诱导表达可见重组融合蛋白在相应分子量大量表达,使用Ara h2多克隆抗体免疫印迹法能检测到目的蛋白。结论:成功克隆、表达了花生主要变应原Ara h2,为其重组变应原应用研究奠定了基础。     

花生过敏原iso-Ara h 3的克隆、表达和免疫学鉴定

采用Touchdown PCR技术从花生cDNA中克隆到花生的过敏原iso-Ara h 3基因,并进行重组蛋白表达,再用Western blot技术鉴定重组蛋白过敏原性。结果显示,构建的pET44a-iso—Ara h 3重组菌能表达iso—Ara h 3蛋白。用8例花生过敏的阳性血清鉴定表明,重组的iso—Ara h 3蛋白血清IgE识别率为12．5％,是一种低过敏原性的过敏原蛋白。     

牛奶过敏原β-乳球蛋白的重组制备及磁微粒化学发光检测法的建立

运用原核系统表达牛奶β-乳球蛋白(Bos d5)蛋白,建立一种纳米磁微粒化学发光方法用于检测牛奶组分过敏原β-乳球蛋白特异性Ig E抗体的含量。通过优化合成牛奶β-乳球蛋白基因,与质粒重组导入Rosetta原核表达菌株中表达目标蛋白,纯化的重组蛋白采用生物素标记后,在化学发光平台上进行过敏原项目检测。获得纯度﹥85%的22.5 kD重组牛β-乳球蛋白,将生物素化的重组蛋白用于牛奶β-乳球蛋白纳米磁微粒检测试剂盒,检测临床110例血清样本,和Phadia进行方法学比对阳性符合率为88.9%,阴性符合率97.3%,总符合率94.5%,P<0.001,χ^2=84.238,Kappa=0.874,其与Phadia参照试剂盒同样具有良好的检测能力。原核表达系统中获得的重组牛奶过敏组分β-乳球蛋白具有较好的免疫活性,开发的免疫诊断试剂盒具备良好的性能,可用于临床辅助诊断。     

表达非洲猪瘟病毒CD2v与P12蛋白的重组伪狂犬病毒的构建

非洲猪瘟(African swine fever,ASF)与伪狂犬病(pseudorabies,PR)分别由非洲猪瘟病毒(African swine fever virus,ASFV)与伪狂犬病毒感染(Pseudorabies virus,PRV)引起的猪(或部分猪)高致死、传染性疾病.目前非洲猪瘟无商业化疫苗,两种疾...     

一种高纯度,无SDS的重组人白细胞介素2制备方法

由Ｅ．ｃｏｌｉ表达的重组白细胞介素２（ｒＩＬ－２）以包含体形式存在于工程菌胞浆中,经超声破碎等步骤处理提取包合体,用盐酸胍（ＧｕＨＣｌ）将其溶解后经ＳｅｐｈａｃｒｙｌＳ－２００分子筛提纯,复性后再用单克隆抗体柱进行亲和层析纯化,结果可使ｒＩＬ－２纯度达９９％以上,平均比活性为１．０×１０７Ｕ／ｍｇ蛋白左右,产品不含ＳＤＳ,残余鼠ＩｇＧ含量测定符合生物制品规程要求。     

人SPRED2 基因重组腺病毒载体的制备及其对K562 细胞

目的:构建携带SPRED2的质粒载体与重组腺病毒载体,并观察其在K562细胞的表达及对ERK信号通路的作用,为Spred2在造血细胞中的作用的研究奠定基础。方法:以HepG2细胞cDNA为模板,RT-PCR克隆SPRED2全长CDS序列,并亚克隆到pCDNA3.0和pshuttle-CMV质粒载体,构建携带SPRED2的真核表达载体pCDNA3.0-Spred2与穿梭载体pshuttle-CMV-Spred2;将线性化pshuttle-CMV-Spred2与腺病毒骨架质粒Adf11p在感受态细胞BJ5183中进行同源重组,产生重组质粒Adf11p-Spred2;后者经线性化后转染至HEK293细胞进行病毒包装;在HEK293细胞扩增病毒颗粒,以CsCl密度梯度离心法进行纯化,TCID50法测定病毒滴度;将病毒颗粒以100MOI感染K562细胞,Western blot检测Spred2过表达情况及Spred2对细胞ERK的影响。结果:经酶切、DNA测序、Western blot检测等方法鉴定,证明pCDNA3.0-Spred2与Adf11p-Spred2携带Spred2序列正确,能够在HEK293细胞、K562细胞正确表达,Spred2过表达能够显著抑制K562细胞ERK活性。结论:成功构建对K562细胞有高感染效率的SPRED2重组腺病毒载体,且Spred2对K562细胞ERK信号通路有显著抑制作用。     

新型重组VPAC2激动剂RD的制备及促进胰岛素功能的分子机制

利用DNA重组、原核表达、Chitin-Beads柱和HPLC纯化、质谱鉴定等技术,制备了一种新型具有抗2型糖尿病功能的VPAC2受体激动剂RD,并初步研究和揭示了其在Ⅱ型糖尿病治疗中有效促进胰岛素信号传导的分子机制。实验结果表明:利用基因重组技术制备的VPAC2受体激动剂RD的分子量为3 785.0 Da,纯度为96%;将重组肽作用于正常或胰岛素抵抗的3T3-L1 脂肪细胞(IR模型细胞),1和5μmol/L 重组肽RD可促进正常3T3-L1脂肪细胞IRS-1 蛋白的表达(分别增加36%和42%),而促进IR模型细胞IRS-1 蛋白的表达增加更为明显(分别增加55%和63%)。IR模型细胞经1,5和10μmol/L重组肽RD处理后,pIRS1(ser307)的表达水平分别比降低了5.9%,10.7%和32.7%。在IR模型细胞中,5和10μmol/L RD处理组,IRS-2蛋白的表达水平分别降低12.8%和40.6%;而1,5和10μmol/L RD各处理组pIRS2蛋白的表达水平分别降低35.1%,40.8%和48.5%。5 and 10μmol/L RD处理的IR模型细胞中Akt蛋白的表达显著增强,表达量分别增加74%和77%。1,5 和10μmol/L的重组肽RD处理的IR模型细胞中,Akt Ser473磷酸化水平分别降低33.9%,64.0%和71.1%;Akt Thr308磷酸化水平分别升高13.5%,78.6%和83.3%。建立了重组VPAC2受体激动剂RD的制备技术,并在体外细胞水平检测了其效果(显著促进正常3T3-L1脂肪细胞及IR模型细胞IRS-1 蛋白的表达;降低IR模型细胞pIRS1(ser307),IRS-2,pIRS2蛋白的表达;促进IR模型细胞Akt蛋白的表达及Akt Thr308磷酸化水平等),为阐明其在2型糖尿病治疗中的分子作用机制及药用研发提供了实验基础。     

新型基因重组PACAP衍生物MPL-2的制备及其抗2型糖尿病作用研究

利用基因工程技术高效制备具有治疗2型糖尿病功能的垂体腺苷酸环化酶激活肽(PACAP)衍生物MPL-2,并以2型糖尿病小鼠(db/db小鼠)为模型在体内研究其抗2型糖尿病的生物学作用。实验结果表明:利用基因工程技术制备的PACAP27衍生多肽MPL-2的分子质量为3 902Da.,纯度达97%,其产率可达29.3mg/L发酵产物;在以db/db小鼠为模型的体内葡萄糖耐量实验中,MPL-2可有效促进小鼠胰岛素第一时相(5~15min)分泌,显著提高小鼠的葡萄糖耐受能力。在MPL-2的长效药效学实验中,经过8周连续用药治疗后,MPL-2可显著提高db/db小鼠的胰岛素敏感性,胰岛素耐量实验60min时MPL-2可将小鼠血糖降至初始值的63.52%;同时,在8周连续用药治疗过程中,与生理盐水(NS)处理组相比,MPL-2可有效降低db/db小鼠的体重、空腹血糖、饮食量、饮水量,分别低于NS组21.98%、21.46%、22.20%、60.07%,而且可显著改善db/db小鼠的血脂常数,生物学作用显著优于多肽BAY55-9837。建立了新型基因重组PACAP27衍生多肽MPL-2的高效制备技术,重组多肽MPL-2可有效改善2型糖尿病db/db小鼠的葡萄糖耐量、胰岛素敏感性、血脂常数,显著降低db/db小鼠的体重、空腹血糖、饮食和饮水量,从而发挥治疗2型糖尿病的生物学作用,可为MPL-2的药用研发提供实验数据。     

草鱼重组瘦蛋白的制备及其对JAK2-STAT3信号通路的作用研究

瘦素(leptin)是主要由脂肪细胞分泌的蛋白质,具有调节机体食物摄入和能量代谢的功能。为了获得具有生物活性的瘦蛋白,本研究采用PCR技术从草鱼脑垂体中扩增出瘦素的cDNA开放阅读框(open reading frame, ORF)序列,用于构建pGEX4T-1-CiLEP重组质粒(带GST标签),并将重组质粒在大肠杆菌BL21中进行原核表达。经SDS-PAGE和Western-blot检测证实,在47 kD处有与预期相对分子质量相符的融合重组瘦蛋白(即含GST标签的草鱼重组瘦蛋白)。体内注射试验结果表明,与注射GST标签蛋白相比,纯化后的融合重组瘦蛋白的注射对草鱼脑垂体和肠道的瘦素受体基因及JAK2-STAT3信号通路相关基因的表达有上调作用。以上结果为进一步研究草鱼重组瘦蛋白对JAK2-STAT3信号通路相关基因表达的影响和深入了解草鱼瘦素基因的功能及其调控机制奠定了基础。     

我国D2-43病毒株PrM-E基因的重组SFV的制备及生物学鉴定

 为构建含PrM E基因的重组SFV病毒 ,将含我国登革 2型病毒PrM E基因的SFV表达载体和辅助载体DNA线性化后 ,进行体外转录 .然后将获得的 2种RNA转录物共转染BHK2 1细胞 ,以RT PCR法证明转染后的细胞培养上清中含有重组SFV .进一步将该重组病毒经蛋白酶激活后可使BHK2 1细胞产生细胞病变 ,并且以间接免疫荧光法在感染细胞内可检测到登革 2型病毒所特有的蛋白 .含我国登革 2型病毒PrM E基因的重组SFV的获得 ,为进一步观察该重组病毒的免疫原性奠定了基础 ,从而为登革新型疫苗的研制提供新途径     

Purification and Recombinant Expression of Major Peanut Allergen Ara h 1

Reaction to peanut, as one of the major food allergens, has become an increasingly common life-threatening disorder. Although peanut allergens have been extensively identified, Ara h 1 is still too expensive to be applied in food safety or clinical utility. In this study, the purification, expression, and immunological analyses of Ara h 1 are investigated. It was shown that a high purity (>95%) of Ara h 1 could be prepared by either purification or expression. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blot, and mass spectroscopy were used to identify the Ara h 1, and it was found that natural Ara h 1 (nAra h 1) and expressed Ara h 1 (rAra h 1) have the same properties, including amino acid sequence. In particular, rAra h 1 reacted positively with anti-nAra h 1 serum, showing their similar immunological property. Thus, by either purification or expression, Ara h 1 could be prepared with low cost, as performed in the present work. SDS-PAGE, mag trix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS), and immunological analysis confirmed that both forms of Ara h 1 had the same properties.     

Identification and characterization of a hypoallergenic ortholog of Ara h 2.01

Peanut (Arachis hypogaea L.), can elicit type I allergy becoming the most common cause of fatal food-induced anaphylactic reactions. Strict avoidance is the only effective means of dealing with this allergy. Ara h 2, a peanut seed storage protein, has been identified as the most potent peanut allergen and is recognized by approximately 90% of peanut hypersensitive individuals in the US. Because peanut has limited genetic variation, wild relatives are a good source of genetic diversity. After screening 30 Arachis duranensis accessions by EcoTILLing, we characterized five different missense mutations in ara d 2.01. None of these polymorphisms induced major conformational modifications. Nevertheless, a polymorphism in the immunodominant epitope #7 (S73T) showed a 56–99% reduction in IgE-binding activity and did not affect T cell epitopes, which must be retained for effective immunotherapy. The identification of natural hypoallergenic isoforms positively contributes to future immunological and therapeutic studies and peanut cultivar development. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Purification of antibody against Ara h 2 by a homemade immunoaffinity chromatography column

Antibodies are used extensively in numerous applications both in vivo and in vitro. To purify anti-Ara h 2 polyclonal antibody, a homemade immunoaffinity chromatography (IAC) column method was established. The properties of homemade column were compared with those of the mAb affinity protein G (MPG) agarose high flow, a commercially available column successfully used in capturing polyclonal antibodies. During antibody purification from rabbits’ antiserum against Ara h 2, the column capacity, recovery, and purification factor were characterized for IAC and MPG. The homemade IAC could separate the corresponding antibody with higher specificity and lower cost but with lower recovery and column capacity than those of MPG. Thus, the homemade IAC is a specific, inexpensive, and suitable method that can be used for various laboratory purifications.     

Detection of genic interactions by analyzing the F2 generation of diallel crosses

Summary The ability of the Hayman and Jinks method of analysis of diallel crosses to detect genic interactions was studied in peanuts. Six traits, measured in the F₂ generation of a diallel cross of four cultivars, were analyzed. In F₂ analyses of the diallel, least squares estimates of variance components D, H₁ , H₂, F, E, were used as an additional criteria for the adequacy of the diallel model. They were found to be in substantial agreement with the tests based on W_r and V_r values, and probably more reliable. The regression of W_r on V_r was shown to be unsuitable to detect duplicate gene type of interactions; it was detected, however, by the ratio of the mean within-F₂ — family variance and the variance among the parents. Using the different criteria, duplicate genes type of interactions was detected for two traits, complementary genes type was detected for one trait and three traits were found to fit the additive-dominance model without any genic interactions.     

Alleviating peanut allergy using genetic engineering: the silencing of the immunodominant allergen Ara h 2 leads to its significant reduction and a decrease in peanut allergenicity

Peanut allergy is one of the most life-threatening food allergies and one of the serious challenges facing the peanut and food industries. Current proposed solutions focus primarily on ways to alter the immune system of patients allergic to peanut. However, with the advent of genetic engineering novel strategies can be proposed to solve the problem of peanut allergy from the source. The objectives of this study were to eliminate the immunodominant Ara h 2 protein from transgenic peanut using RNA interference (RNAi), and to evaluate the allergenicity of resulting transgenic peanut seeds. A 265-bp-long PCR product was generated from the coding region of Ara h 2 genomic DNA, and cloned as inverted repeats in pHANNIBAL, an RNAi-inducing plant transformation vector. The Ara h 2-specific RNAi transformation cassette was subcloned into a binary pART27 vector to construct plasmid pDK28. Transgenic peanuts were produced by infecting peanut hypocotyl explants with Agrobacterium tumefaciens EHA 105 harbouring the pDK28 construct. A total of 59 kanamycin-resistant peanut plants were regenerated with phenotype and growth rates comparable to wild type. PCR and Southern analyses revealed that 44% of plants stably integrated the transgene. Sandwich ELISA performed using Ara h 2-mAbs revealed a significant ( P <  0.05) reduction in Ara h 2 content in several transgenic seeds. Western immunobloting performed with Ara h 2-mAb corroborated the results obtained with ELISA and showed absence of the Ara h 2 protein from crude extracts of several transgenic seeds of the T₀ plants. The allergenicity of transgenic peanut seeds expressed as IgE binding capacity was evaluated by ELISA using sera of patients allergic to peanut. The data showed a significant decrease in the IgE binding capacity of selected transgenic seeds compared to wild type, hence, demonstrating the feasibility of alleviating peanut allergy using the RNAi technology.     

一株龙葵内生细菌SDE06去除Cd2+的实验

植物内生菌广泛存在于各种植物中, 对宿主的生命活动产生了各种影响。本研究通过对重金属镉(Cd)超累积植物龙葵(Solanum nigrum L.)内生菌优势种进行分离纯化, 并用含Cd2+培养基初步筛选, 得到7株有抗性的菌株, 分别命名为SDE01-07,其中SDE06在Cd2+浓度为80 mg/L的条件下仍能生长。经鉴定此株菌属芽孢杆菌属(Bacillus sp.)。对SDE06在不同条件下去除Cd2+的情况进行研究, 结果表明：正交实验得最佳实验条件为培养时间36 h, pH 6.0, 温度37°C     

病原菌诱导转录的水稻Rim2家族转座酶编码亚组的结构与分布

以基因组克隆Rim2-569为代表,分析了该家族中转座酶编码亚组的分子结构,同时对Rim2因子在染色体和不同水稻品种之间的差别分布情况进行了研究。序列分析表明,Rim2-569具有完整的16-bp的末端颠倒重复序列(TIRs)、若干正向和反向的16-bp的亚末端重复(STRs)以及插入位点3-bP的同向重复。它的TIRs上具有保守序列CACTG,有别于以往报告的CACTA转座子。该因子含有一个编码区,与已报告的Rim2 cDNA的ORF基本一致,其预测编码蛋白与CACTA转座子编码的转座酶TNP2和TNPD有低度的同源性。该亚组的其它因子的分子结构均与Rim2-569的相似,但这些因子预测0RF长度上存在着差异,反映了结构上的多样性。对检索到的Rim2因子的定位作图表明,它们在已测序拼接完成的第1、4和10号染色体上呈不均匀分布,以着丝点附近的分布频率为最高。PCR反应显示,Rim2编码因子在品种之间存在着编码序列多态性。