Prokaryotic expression, polyclonal antibody preparation of the stilbene synthase gene from grape berry and its different expression in fruit development and under heat acclimation

Stilbene synthase (STS, EC 2.3.1.95) leads to the production of resveratrol compounds, which are major components of the phytoalexin response against fungal pathogens of the plant and are highly bioactive substances of pharmaceutical interest. STS expression and regulation are important. Temperature is one of the main external factors affecting phytoalexin accumulation in plant tissues, the effect of temperature on resveratrol synthesis and stilbene synthase expression in grape berries has not been reported before. Here we cloned the full-length sts cDNA with 1179 bp from grape berry via PCR, and then introduced into an expressed plasmid pET-30a(+) vector at the EcoRI and XhoI restriction sites. With the isopropyl-β-d-thiogalactoside (IPTG) induced, the pET-sts was highly expressed in Escherichia coli BL21 (DE3) pLysS cells. A fusion protein with the His–Tag was purified by Ni-NTA His · Bind Resin and then used as the antigen to immunize a New Zealand rabbit. Furthermore, the antiserum was precipitated by 50% saturated ammonium sulfate and DEAE-Sephadex A-50 chromatography to obtain the immunoglobulin G (IgG) fraction. These results provide a substantial basis for the further studies of the STS in grape berry as well as in other species of plants. The sts expression in fruit development and in response to heat acclimation was then assayed. The results indicated STS was regulated in fruits depending on the developmental stage and significantly accumulation of STS mRNA and synthesis of new STS protein during the early of heat acclimation, this work offers an important basis for further investigating the mechanism of post-harvest fruit adaptation to environmental stresses.     

家蚕丝氨酸蛋白酶抑制剂4(serpin-4)的基因克隆、原核表达和多克隆抗体制备

丝氨酸蛋白酶抑制剂4(serpin-4)为丝氨酸蛋白酶抑制剂家族中的一员.本研究旨在研制高效价的家蚕Bombyx mori serpin-4多克隆抗体,为深入研究serpin-4基因的生理功能打下物质基础.首先于家蚕脂肪体中克隆了serpin-4基因,利用基因重组技术构建了pET28a-serpin-4原核表达载体,经...     

游仆虫Rab家族成员Eorab1f基因的克隆、表达及多克隆抗体制备

Rab家族蛋白在真核细胞囊泡转运过程中起关键作用。为进一步研究该家族成员的功能, 本研究从八肋游仆虫(Euplotes octocarinatus) 大核基因组中克隆得到Rab蛋白家族中一个新Rab蛋白基因(命名为Eorab1f)的编码区。该开放读框长624 bp, 含有两个通用终止密码子TGA。通过定点突变将TGA突变为TGC。突变后的Eorab1f克隆入原核表达载体pRSETc 中, 工程菌E coli BL21 (DE3) /pRSETc Eorab1f 经IPTG诱导表达,SDS- PAGE分析表明, 有一分子量约为26 kD的特异蛋白条带出现。表达产物经IMAC金属螯合亲和层析及Re source- Q阴离子交换层析纯化, 获得电泳纯的蛋白。Brandford法检测表明每升发酵液中可获得纯化的目的蛋白1 353 mg。Western blotting印迹分析表明该蛋白为融合有6个His的Eorab1f蛋白。纯化的Eorab1f融合蛋白免疫大鼠制备多克隆抗体, ELISA法测得抗体效价为1∶5 000。用制备的多克隆抗体检测八肋游仆虫的蛋白提取物,表明Eorab1f蛋白在游仆虫细胞内表达, 同时表明所得的多克隆抗体特异性良好。     

菜蛾盘绒茧蜂多分DNA病毒EP-1-like基因克隆、原核表达与多克隆抗体制备方法

本实验提取被菜蛾盘绒茧蜂寄生后24h的小菜蛾幼虫体内总RNA,反转录合成cDNA,以此为模板PCR扩增出菜蛾盘绒茧蜂多分DNA病毒（Cotesia vestalis polydnavirus,CvBV）EP-1-like基因,将其分别克隆到表达载体pET30a、pET28a中,转化宿主菌BL21（DE3）,获得单克隆重组质粒pET-30a-EP1L和pET-28a-EP1L。经IPTG诱导,pET-28a-EP1L成功表达了约34.8kDa的包涵体蛋白。将诱导条件优化以后,采用割胶回收的方法纯化包涵体,将纯化后的表达蛋白免疫新西兰大耳兔制备多克隆抗体。ELISA分析表明制备的抗体效价达1：128000,Western blot检测证明抗体具有良好的免疫反应特异性。     

二点委夜蛾非典型嗅觉受体AlepOrco的基因克隆、原核表达及多克隆抗体制备

【目的】非典型嗅觉受体(olfactory receptor co-receptor, Orco)与典型嗅觉受体共同形成离子通道,在昆虫嗅觉识别中具有至关重要的作用。本研究旨在克隆和表达二点委夜蛾Athetis lepigone Orco基因,明确其分子特性,为进一步研究该基因在二点委夜蛾中的功能奠定基础。【方法】将二点委夜蛾雌雄成虫触角转录组数据建立本地数据库,通过生物信息学分析获得二点委夜蛾Orco同源基因AlepOrco;利用RT-PCR方法克隆二点委夜蛾AlepOrco基因全长,并在pGEX-6P-1/BL21(DE3)系统中进行了该基因开放阅读框(ORF)的原核表达,制备多克隆抗体,用Western blot检测抗体特异性;利用qPCR技术检测该基因在二点委夜蛾雌雄成虫不同组织(喙、触角、去除触角和喙的头、胸、腹、足和翅)中的表达谱。【结果】获得了二点委夜蛾AlepOrco的cDNA(GenBank登录号:MN583125)全长序列,开放阅读框长1 422 bp,编码473个氨基酸,序列中有7个跨膜结构区,预测等电点为8.59,分子量为53.40 kD。SDS-PAGE和We...     

O-GlcNAcase抗原片段的选择、优化表达和多克隆抗体的制备

为了探讨O-GlcNAc修饰的生物学作用和相关疾病的发病机理,需制备高效、专一的O-GlcNAcase (OGA) 抗体。通过对人源OGA蛋白进行序列分析发现,氨基端1~350 aa片段 (sOGA) 抗原性和亲水性较强,将该片段构建至原核表达载体pET-28a,并在大肠杆菌Escherichia coli BL21(DE3) 中进行诱导表达,通过优化IPTG浓度 (0.05 mmol/L) 和诱导时间 (10 h) 获得了高可溶性表达的重组蛋白酶。采用Ni-NTA亲和层析和分子筛层析对重组蛋白进行了纯化,SDS-PAGE检测分子量的大小 (45 kDa) 和纯度 (95％以上)。以4-MU-O-GlcNAc为荧光底物,检测到sOGA的糖苷酶活性为106 nmol/(min·mg),表明该片段是OGA糖苷酶的活性区域。以此片段作为抗原免疫新西兰大白兔,以CNBr活化Sepharose 4B微珠纯化抗血清制备OGA特异性多克隆抗体。Western blotting和ELISA检测表明,该抗体可以特异识别含有OGA糖苷酶活性区域的多种变体,检测灵敏度为0.11 ng/mL (效价为1∶80 000),可应用于O-GlcNAcase生物功能研究。     

小菜蛾普通气味结合蛋白2基因的原核表达与多克隆抗体制备

本实验提取羽化3 d的小菜蛾Plutella xylostella成虫触角总RNA,反转录合成cDNA,以此为模板PCR扩增出小菜蛾普通气味结合蛋白2基因,大小为492 bp,Blast结果显示与多种昆虫的GOBP2具有较高的同源性.将该基因克隆到表达载体pMAL-c4E中,转化宿主菌TB1(DE3),获得单克隆重组质粒pMAL-c4E-GOBP2.IPTG成功诱导pMAL-c4E-GOBP2表达出约60 kDa的融合蛋白.优化诱导条件为3 mmol/L终浓度IPTG、6 h,可获得大量可溶性蛋白.表达的融合蛋白通过亲和色谱法纯化、免疫新西兰大白兔制备多克隆抗体.ELISA分析表明制备的抗体效价达1:1.28×105.     

RAP蛋白的纯化和抗体制备

从04018金黄色葡萄球菌培养上清分离纯化获得相对分子质量为38000,具有激活RNAⅢ作用的RAP蛋白。用该蛋白免疫家兔得到效价为1：128000的多抗血清。纯化后的抗体可以特异结合RAP并抑制其激活RNAⅢ转录的作用。     

拟态弧菌VMH蛋白的原核表达及其多克隆抗体制备

目的实现拟态弧菌热不稳定性溶血素(VMH)的原核表达,制备兔抗VMH蛋白的多克隆抗体。方法根据GenBank上已有的拟态弧菌vmh基因序列,设计并合成引物,通过PCR方法扩增vmh基因。PCR纯化产物酶切后,定向插入到PET-32a表达载体构建重组表达质粒PET-32a-vmh。重组表达质粒转化至E.coli Rosetta感受态细胞,在IPTG诱导下进行VMH蛋白表达。SDS-PAGE分析重组VMH蛋白(rVMH)的表达形式,并分别采用兔血平板扩散法和Western blot检测其溶血活性和免疫反应性。用纯化的rVMH蛋白免疫新西兰大白兔,3次免疫后采集免疫血清,采用饱和硫酸铵分级沉淀结合亲和层析法纯化多克隆抗体,并检测其纯度与效价。结果重组表达质粒PET-32a-vmh诱导表达后,经SDS-PAGE分析发现分子量约为77.8kDa的rVMH蛋白主要以包涵体形式表达,该蛋白经变性复性后具有溶血活性和免疫反应性。兔抗rVMH蛋白的多克隆抗体经纯化后,其纯度达95%,ELISA效价为1∶26843545600,琼扩效价为1∶32。结论成功制备了rVMH蛋白及其多克隆抗体,为进一步采用噬菌体肽库筛选技术鉴定VMH蛋白表位提供了物质基础。     

Prokaryotic expression of pathogenesis related protein 1 gene from Nicotiana benthamiana: antifungal activity and preparation of its polyclonal antibody

The nucleotide sequence of the pathogenesis-related protein 1(PR-1) gene was obtained from Nicotiana benthamiana using RT-PCR. Restriction enzyme cutting sites of EcoRI and NotI were introduced to the ORF fragments of PR-1, they were then linked together with pET-30a (+) and transformed into E. coli BL21 (DE3). The target protein was induced by 1.5?mM IPTG, at 37°C for 4?h. The expressed protein was purified by Ni-NTA and an anti-NbPR-1 polyclonal antibody was prepared using rabbits. The antibody could detect the expression of PR-1 in N. benthamiana and other Nicotiana plants. NbPR-1 protein has four α-helices and two β-sheets by homology modeling. Furthermore, the purified NbPR-1 protein exhibited a broad-spectrum antifungal activity.     

鸡传染性法氏囊病病毒非结构蛋白基因的克隆、表达及多克隆抗体制备

利用RT-PCR技术从传染性法氏囊病病毒(IBDV)TL2004株感染鸡胚尿囊液中扩增到VP5基因,进而构建了T7启动子控制下的N端GST-Tag融合表达质粒pGEX-VP5。序列测定表明VP5基因全长438bp,编码一个由145个氨基酸组成的VP5蛋白。将pGEX-VP5转化大肠杆菌BL21,在IPTG的诱导下高效表达了GST-VP5融合蛋白(44kD)。通过包涵体纯化的方法,获得的较高纯度的融合蛋白,免疫新西兰兔,Western blot和ELISA分析表明,制备的融合蛋白抗血清效价在1∶12800以上,并具有良好的免疫反应特异性,为进一步研究VP5在IBDV复制与致病中的作用,以及研制IBDVVP5基因缺失疫苗打下了良好的基础。     

大肠杆菌FtsZ蛋白原核表达及多克隆抗体的制备与鉴定

为制备特异性抗大肠杆菌丝状热敏蛋白Z(Escherichia coli filamentous thermosensitive protein Z,Ec-FtsZ)多克隆抗体,将Ec-FtsZ基因进行化学合成后连接pET-22b(+)表达载体,构建重组质粒Ec-FtsZ-pET-22b(+)。将重组质粒转化到大肠杆菌E.coli BL21(DE3)中进行Ec-FtsZ原核表达与表达条件优化,以HisTrap层析柱进行Ec-FtsZ的分离纯化,再以孔雀绿法进行Ec-FtsZ GTPase(Guanosine triphosphatase)活性测定。使用纯化的Ec-FtsZ为抗原免疫大鼠制备多克隆抗体,经酶联免疫吸附测定实验(Enzyme-linked immunosorbent assay,ELISA)、Western blotting实验和免疫荧光实验鉴定,抗Ec-FtsZ多克隆抗体效价可达1∶256 000且具有良好的抗原特异性。抗Ec-FtsZ多克隆抗体的成功制备为Ec-FtsZ生物学功能研究和生化检测奠定了实验基础。     

大肠埃希菌Mn-SOD基因的克隆、表达及多克隆抗体制备

目的实现Mn-SOD基因在大肠埃希菌中的高可溶性表达,制备Mn-SOD的多克隆抗体。方法用PCR方法从一株野生型大肠埃希菌（E.coli）基因组中扩增Mn-SOD基因编码区．将它克隆到原核表达载体上进行大量表达和纯化,再用纯化的蛋白对新西兰大白兔进行背部多点注射,40d后取其血清,用Western-blot印迹实验测定抗体效果。结果SDS-PAGE分析表明SOD的表达量约为细菌总蛋白的50％;黄嘌呤氧化酶法测定表达蛋白活性,结果表明每毫克菌体可溶性总蛋白中表达产物酶比活为3921．77U／mg,是对照BL21的276．77倍;并制备了高效价的多克隆抗体。结论该研究成功地构建了大肠埃希菌Mn-SOD基因高效原核表达系统,所表达的Mn-SOD具有良好的免疫原性和免疫反应性。     

Overexpression, refolding, purification of Erbin PDZ domain from Escherichia coli and preparation of its polyclonal antibody

The Erbin was recently identified. The antibody against Erbin has not been commercially available. As a new member of peripheral protein LAP family and novel type of adaptor protein, its functions and binding partners are not completely known. In the present study, cDNA encoding PDZ domain of Erbin was inserted in a prokaryotic expression vector. His-tagged recombinant protein was overproduced in E. coli and purified by Ni-NTA column chromatography. About 14.4 mg of the purified protein was obtained from 500 mL of cell culture. The purity of the recombinant protein was higher than 90%. The polyclonal antibody against this protein was raised. The antibody can recognize both denatured and natural Erbin protein. It will be used to further identify the new binding partners of Erbin and study its unknown functions.     

游仆虫中心蛋白在大肠杆菌中的高效表达和多克隆抗体制备

中心蛋白是一种在微管组织中心的复制和分离中起着重要作用的蛋白质。为了进一步进行中心蛋白结构和功能的研究 ,我们克隆了单细胞真核生物游仆虫中心蛋白基因并构建了重组表达质粒pGEX 6P EoCen ,其在大肠杆菌BL2 1中经IPTG诱导后获得了大量的可溶性表达 ,融合蛋白表达水平达到了细菌总蛋白的 32 6 %。GST抗体进行Westernblotting检测结果为阳性。经GST亲和层析和superdex 75凝胶层析后得到 90 %以上电泳纯的蛋白。用纯化后的蛋白免疫大鼠产生抗血清 ,经ELISA检测抗体效价达 1∶2 5 6 0     

家蝇防御素在大肠杆菌中的表达、纯化与抗体制备

家蝇防御素是从家蝇中克隆得到的1种抗菌肽。为了进一步研究家蝇防御素的功能和制备特异性抗体,采用大肠杆菌表达外源蛋白的方法, 进行了家蝇防御素原核表达的研究。根据克隆到的家蝇防御素基因(Mdde) 的cDNA序列, 设计特异性引物, PCR 扩增成熟肽的cDNA片段, 将成熟肽序列重组到表达载体pGEX 4T 1中, 构建m Mdde/pGEX 4T 1重组表达载体, 在大肠杆菌BL21 中诱导表达, 重组表达的融合蛋白GST Mdde占菌体总蛋白的33 4%。纯化得到GST Mdde后, 再用凝血酶将其从特定位点切开, 得到表达的m Mdde。液体抑菌实验结果初步表明, 表达的融合蛋白GST Mdde对细菌生长有一定的抑制作用。利用纯化的GST Mdde融合蛋白, 制备了抗血清。     

人SUMO-3基因原核表达及多克隆抗体制备

构建人SUMO-3基因的原核表达载体pET41a(+)-SUMO-3,表达重组GST-SUMO-3融合蛋白,制备人SUMO-3多克隆抗体。试验结果显示,通过PCR方法从重组质粒pEYFP-SUMO-3中克隆到的SUMO-3 N端93个氨基酸的基因序列与NCBI上提供的序列一致,重组质粒pET41a(+)-SUMO-3构建成功;重组pET41a(+)-SUMO-3在E.coli.BL21 (DE3) pLysS中表达GST-SUMO-3融合蛋白,分子量为44.0 kDa,与预期分子量一致;采用亲和层析纯化融合蛋白GST-SUMO-3并免疫家兔,获得人SUMO-3抗体;Western blot 检测显示该抗体可以特异性识别SUMO-3,ELISA检测结果成阳性,抗体效价约为1: 20000。实验结果为进一步研究人SUMO-3及SUMO第二类家族的功能提供了有用工具。     

High-level expression, polyclonal antibody preparation and sub-cellular localization analysis of mouse Rhox5 protein

Mouse reproductive homeobox on the X chromosome (Rhox) is a novel homeobox gene cluster. Rhox5, also called Pem, belongs to the beta subcluster of Rhox. Codon analysis indicated that the cDNA contains 16% of codons rarely used in Escherichia coli. To achieve high-level expression of Rhox5, the coding sequence of Rhox5 was amplified and subcloned into the prokaryotic expression vector pET22b (+) in order to produce 6His-tagged fusion protein in the modified BL21 (DE3) cells, namely Rosetta2 (DE3) cells. The 6His-tagged Rhox5 was expressed efficiently in Rosetta2 (DE3), compared with marginal expression in BL21 (DE3). The fusion protein amounted to 16% of the total bacterial proteins after induction with 0.4mM IPTG for 1.5h at 37 degrees C. After purification, Rhox5-6His was used to immunize New Zealand white rabbits following standard protocol. The homemade antiserum could detect both endogenous Rhox5 protein expressed in eukaryotic cells (Cos-7) and exogenous GFP-Rhox5 protein. Furthermore, the antiserum was used to determine the localization of Rhox5 in NIH3T3 cells using an immunofluorescence technique. The results demonstrated that Rhox5 was localized predominantly in the nucleus. Preparation of the anti-Rhox5 polyclonal antibody will facilitate further functional study of Rhox5.     

Prokaryotic expression and polyclonal antibody preparation of a novel Rab-like protein mRabL5

Rab GTPases, which belong to the Ras superfamily, represent a group of small molecular weight GTP binding proteins that are involved in various steps along the exocytic and endocytic pathways. We first identified mRabL5 (GenBank Accession No. NP_080349), a novel Mus musculus Rab-like protein, present as a Golgi-associated protein. Here we presented the results of the cloning, prokaryotic expression, purification, and polyclonal antibody production of the novel Rab-like protein. In order to obtain a specific antibody against mRabL5, we prepared two GST fusion proteins, full-length mRabL5 GST fusion protein and mRabL5 C terminus GST fusion protein, to immunize rabbits. Western blot analysis showed that both antibodies prepared against full length of mRabL5 and its C terminus, respectively, can recognize mRabL5 protein. Immunofluorescence of mRabL5 in NIH3T3 cells using the two antibodies showed its perinuclear clustering distribution pattern. The polyclonal antibodies preparation against mRabL5 provided a good tool for us to study the functional involvement of mRabL5.