人Cuedc2真核表达载体的构建及其在HEK293细胞中的表达

目的:构建人Cuedc2的真核表达载体,并进行体外验证。方法:提取人卵巢癌细胞总RNA,通过RT-PCR的方法其反转录为cDNA;以之为模板,利用PCR获得Cuedc2的编码区,纯化后克隆入pcDNA3.1myc-his(-),利用菌落PCR及DNA测序进行鉴定。最后,采用瞬时转染的方法,将所构建的重组CUEDC2真核表达载体通过脂质体转染HEK293细胞,48h后通过western blot检测Cuedc2蛋白的表达。结果:Cuedc2编码区cDNA正确地插入真核表达载体pcDNA3.1myc-his(-)中,western blot检测证实其在HEK293细胞中表达,而空载体转染的细胞为阴性,表明所构建的pcDNA3.1myc-his(-)-Cuedc2能够在体外有效表达。结论:本研究成功地克隆了人Cuedc2 cDNA,构建了重组真核表达载体,并在HEK293细胞中有效表达,为进一步研究人Cuedc2的功能及其与肿瘤的关系奠定了实验基础。     

Direct cloning of a target gene from a pool of homologous sequences: complete cDNA sequence of a weak neurotoxin from cobra Naja kaouthia

Selective cloning of the cDNA coding for a weak neurotoxin (WTX) from cobra N. kaouthia including the 5'- and 3'-non-translated regions (NTR) is described. The known amino acid sequence of WTX was used together with the nucleotide sequence of a weak neurotoxin NNAM2 from cobra Naja atra, to design WTX-specific primers for direct amplification of an internal WTX cDNA fragment by RT- PCR. The sequence of the complete WTX cDNA was determined in sequencing runs on internal PCR products, cloned 3'- and 5'-RACE-fragments and several full-length cDNA clones. The cDNA coding sequence is in excellent agreement with the previously determined WTX amino acid sequence, has a high homology with other known weak toxin cDNAs, whereas even higher homology (up to 96%) with several classes of 3-finger toxins was detected in the 59 bp 3'-NTR consensus sequence. A possible function of the highly conserved nucleotide sequence elements is discussed.     

人促红细胞生成素基因组基因和cDNA的克隆及其在COS－7细胞中的表达

利用ＰＣＲ技术,从正常人胎肝染色体ＤＮＡ中克隆到长度为１５７２ｂｐ的人促红细胞生成素（ＥＰＯ）基因组基因片段,它包含除第一个外显子和第一个内含子外所有外显子及内含子。再人工合成１３ｂｐ外显子１的编码区,并与１５７２ｂｐ片段拼接,从而得到除第一个内含子的人促红细胞生成素基因组基因。将克隆得到的ＥＰＯ基因插入载体ｐＳＶ２－ｄｈｆｒ得到ｐＳＶ２－ＥＰＯ表达载体,转染ＣＯＳ－７细胞后获得高效表达。利用自行研制的小鼠抗人ＥＰＯ单抗及兔抗人ＥＰＯ多抗,对表达产物进行ＥＬＩＳＡ定量测定,细胞分泌ＥＰＯ量高达２５１±７Ｕ／ｍｌ．Ｋｒｙｓｔａｌ法测得体外生物活性２４１．５±６．５Ｕ／ｍｌ．用ＥＰＯ单抗免疫沉淀结合ＳＤＳ－ＰＡＧＥ对转染细胞的表达产物做了进一步鉴定,清晰地看到了ＥＰＯ条带。从高效表达ＥＰＯ的转染细胞中分离纯化ｍＲＮＡ,用ＲＴ－ＰＣＲ方法扩增并克隆到ＥＰＯ的ｃＤＮＡ,这为ＥＰＯ在其它系统中的表达及ＥＰＯ的功能与结构的研究打下了基础。     

小鼠 LRRC 10腺病毒载体构建及其在心肌细胞中的表达

目的：构建含有小鼠Lrrc10（Leucine-rich Repeat Containing protein 10）基因的重组腺病毒表达载体。方法：设计小鼠Lrrc10特异性引物,以小鼠cDNA为模板,通过PCR扩增出mLrrc10的编码区,并引入HA标签蛋白和Sal Ι酶切位点。该片段经凝胶电泳纯化后插入pMD-18 T载体。测序后,用Sal Ι和Hind III酶切,将目的片段亚克隆至pAd-track-cmv穿梭载体中。用PmeΙ线性化后,用100 ng转化细菌BJ5183,在细菌内同源重组后得到 pAd-Lrrc10质粒。pAd-Lrrc10经PacⅠ线性化后用LipofectamineTM2000转染293A细胞,包装得到含Lrrc10基因的病毒重组子。将病毒重组子在293A细胞中扩增后,反复冻融得到滴度较高的含Lrrc10的病毒液。将收集的病毒液感染心肌细胞,绿色荧光观察 GFP、免疫印迹检测Lrrc10-HA蛋白的表达。结果：用病毒液感染原代心肌细胞,24小时后在荧光显微镜下可观察被感染的细胞发出绿色荧光,提取心肌细胞总蛋白,Western可检测到Lrrc10-HA融合蛋白的表达。结论：小鼠Lrrc10腺病毒载体构建成功,并可将编码Lrrc10-HA的目的片段导入心肌细胞中表达。     

肿瘤MUC1/Y的克隆及其胞外段在大肠杆菌中的可溶性表达、纯化和鉴定

为获得MUC1 Y全长cDNA及其胞外段蛋白 ,以用于进一步的生物学功能及肿瘤生物学治疗的研究 .利用RT PCR从HeLa细胞中扩增MUC1 Y全长cDNA ;PCR扩增其胞外段 ,克隆到原核表达载体pGEX 2T ,转化DH5a菌 ,诱导表达 ;亲和层析纯化 ;凝血酶酶切、GST活性及N端蛋白测序鉴定 ;免疫家兔制备多克隆抗体 .所得MUC1 YcDNA的开放读框为 759bp ,登录于GenBank(AF12 552 5) .其信号肽编码序列缺失 9bp ,第 3 3 1位发生G A转换 ,造成缬氨酸突变为蛋氨酸 .表达获得约 4 0kD融合蛋白GST Yex ,占菌体总蛋白 2 5%～ 3 0 % ,其中 70 %～ 80 %为可溶性 ,经亲和层析一步纯化 ,纯度 >90 % ,GST比活性为 0 2 1U μg .凝血酶酶切后的N端蛋白序列测定表明与已知序列完全一致 ,抗血清ELISA效价为 1∶2 50 0 0 0 .结果表明 ,克隆到发生碱基缺失和突变的MUC1 Y全长cDNA ,获得MUC1 Y胞外段蛋白及其多抗 ,可进一步用于相关研究 .     

Sparc基因的克隆及其在HEK293细胞中的表达

目的：为探讨SPARC（secreted protein acidic and rich in cysteine）在人恶性肿瘤发生、发展中的作用及其分子机制,进一步明确SPARC发挥作用的方式及其与肿瘤发生类型的关系。方法：我们首先提取了人乳腺癌细胞系MCF-7的总RNA,在对总RNA进行纯度与定量检测后,利用RT-PCR的方法,以该总RNA为模板,将其反转录为cDNA;再设计引物,以该cDNA为模板,利用PCR扩增出包含Sparc编码区的DNA片段,将该产物纯化后通过T-A克隆连接入pMD20-T载体,利用菌落PCR及DNA测序进行鉴定。以pMD20-T-Sparc为模板,我们设计了特异的针对Sparc全长编码区的引物,并在引物5＇端分别加入BamHI、HindIII酶切位点,通过PCR将Sparc编码区扩增出来,经纯化及双酶切后与真核表达载体pcDNA3.1myc-his（-）相连,再经菌落PCR和DNA测序进行鉴定。通过瞬时转染的方法,利用脂质体将所构建的重组SPARC真核表达载体转染HEK293细胞,48h后裂解所培养的细胞,使用western blot检测有无SPARC的表达。结果：测序证实所克隆的Sparc编码区cDNA正确地插入pcDNA3.1myc-his（-）中,western blot检测证实其在HEK293细胞中得到表达,而空载体转染的细胞则无表达,说明所构建的pcDNA3.1myc-his（-）-Sparc能够成功表达。结论：我们成功克隆了人Sparc cDNA,构建了其真核表达载体,并在HEK293细胞中得到有效表达,从而为进一步研究人SPARC的功能及其与肿瘤的关系奠定了基础。     

小鼠金属硫蛋白 Ⅰ cDNA编码序列的克隆及其在昆虫细胞中的表达

将质粒ｐＢＸ－ＭＴ上的小鼠ＭＴ－ⅠｃＤＮＡ片段切下作为模板,通过ＰＣＲ方法删除该片段的非编码序列,将编码序列克隆到质粒ｐＢＳ－ＳＫ中,经ＤＮＡ序列测定后证明其克隆序列正确．再将ＭＴ－ⅠｃＤＮＡ编码序列插入到转移载体ｐＢａｃＰＡＫ８的ＢａｍＨⅠ和ＥｃｏＲⅠ位点之间,通过磷酸钙／ＤＮＡ共转染方法将其导入昆虫细胞Ｓｆ９中,以Ｗｅｓｔｅｒｎｂｌｏｔ和ＤｏｔＥＩＡ方法对表达产物进行了检测,表达量为１ｍｇ／Ｌ     

Expression of the transglutaminase gene in Escherichia coli.

1. The cDNA gene coding for the enzyme transglutiminase (EC 2.3.2.13) was cloned into the pUC18 oriented for expression from the lac promoter. 2. DNA sequencing of the 5' end showed that the cDNA was missing the sequence coding of the N-terminal 30 amino acids. 3. The truncated gene was then cloned into pKK233-2, and the recombinant product was produced in Escherichia coli. 4. A gene construct coding for the complete protein was generated by inserting an oligonucleotide for the missing 30 amino acids into the Eco RI site of the pUC18 clone. 5. A consensus Shine-Dalgarno sequence and translational start codon were positioned at the 5' end of the linker. 6. Immunoblotting experiments of E. coli JM105(pUC18-TGase) indicated the expression of the transglutaminase gene. 7. The cell lysate as well as the partially purified transglutaminase showed no detectable enzyme activity.     

恒河猴tPA基因的克隆、测序与真核表达

目的对恒河猴tPA编码区cDNA进行测序和表达.方法采用RT-PCR方法从恒河猴淋巴细胞中扩增tPA基因,将获得的cDNA克隆于T载体,序列确定后再克隆至真核表达载体.结果测序结果表明恒河猴tPAcDNA编码区与人tPAcDNA编码区的核苷酸序列同源性为96%,由此所推导的氨基酸序列的同源性为97.5%.随后将恒河猴tPAcDNA克隆于真核表达载体,转染CHO细胞后成功表达出了有活性的tPA.培养上清检测结果显示其活性约为50?U/ml,略低于人tPA在CHO细胞中表达产物的活性.结论本研究首次报道了恒河猴tPA基因编码区的全长cDNA序列并获得了有活性的恒河猴tPA真核表达产物.将为进一步比较灵长类动物间tPA的生物学特性奠定基础.     

Molecular cloning and expression of rat liver N-heparan sulfate sulfotransferase.

N-Heparan sulfate sulfotransferase catalyzes the transfer of sulfate from 3'-phosphoadenosine 5'-phosphosulfate to the nitrogen of glucosamine in heparan sulfate. The enzyme has been previously purified to apparent homogeneity from rat liver (Brandan, E., and Hirschberg, C. B. (1988) J. Biol. Chem. 263, 2417-2422). We have now cloned the rat liver enzyme using the following strategy: (a) the amino acid sequence was obtained from tryptic peptides of the purified protein, (b) mixed oligonucleotides were generated based on the sequence of the tryptic peptides, (c) a polymerase chain reaction fragment was obtained using mixed oligonucleotide interprimer amplification of cDNA, and (d) this fragment was used to screen rat liver lambda gt 10 and lambda ZAP libraries. Three clones were obtained, one of which seems to contain the complete coding sequence of the N-heparan sulfate sulfotransferase (N-HSST). Evidence that the cDNA clone corresponds to the previously purified and characterized N-HSST was the following: (a) the predicted sequence of the N-HSST contains all of the 11 tryptic peptides obtained from the purified protein, (b) when a cDNA containing the sequence coding for the N-HSST was introduced in a eukaryotic expression vector and transfected in COS-1 cells, the enzyme activity was expressed 9-fold over controls, and (c) the characteristic of the predicted protein fits with the purified protein in terms of molecular weight, membrane localization, and its being an N-linked glycoprotein. The size of the longest cDNA isolated is 4.1 kilobases, which is in close agreement with the 4.2-kilobase size of one of the mRNA observed in Northern analyses. In addition, messages of 7.0 and 8.5 kilobases were also observed, suggesting that a large portion is untranslated. The latter messages were the major mRNA species detected.     

人脑源性神经营养因子基因的克隆及在大肠杆菌中表达

人脑源性神经营养因子基因的克隆及在大肠杆菌中表达何晓龙,路长林,王成海（第二军医大学神经生物学教研室,上海２００４３３）关键词神经营养因子;基因克隆脑源性神经营养因子（ｂｒａｉｎ－ｄｅｒｉｖｅｄｎｅｕｒｏｔｉｃ…ｉ。血。ｔｏｒ,ＢＤ贾助是Ｂａｄｅ等人...     

单纯疱疹病毒2型感染细胞多肽27真核表达质粒的构建及表达

为了构建单纯疱疹病毒2型(HSV-2)感染细胞多肽27(ICP27)真核表达质粒,应用PCR技术从HSV-2 333株的基因组中扩增ICP27基因,并连接至真核表达载体pEGFPC2,对阳性克隆进行菌落PCR、酶切和测序鉴定后,成功构建了重组质粒pEGFPC2-ICP27。用X fect转染试剂盒将重组质粒pEGFPC2-ICP27转染至Vero细胞中,并用RT-PCR及W estern b lot-ting检测其表达情况。结果显示,ICP27基因在Vero细胞中得到正确表达。真核表达质粒pEGFPC2-ICP27的构建成功,为进一步研究ICP27对宿主细胞的影响奠定了基础。     

中国人促红细胞生成素cDNA的克隆及其在COS—7细胞中的表达

利用PCR技术,以中国人促红细胞生成素(EPO)次全基因组为模板,进行了基因修补和重组,克隆出EPO cDNA全序列。同时发现中国人EPO cDNA与国外的克隆比较有一个核苷酸的差异,导致第62位氨基酸是丝氨酸,不是亮氨酸。将人EPO cDNA基因插入表达载体pSV2-dhfr中的不同克隆位点,构建了6种不同的转移载体质粒,即pSV2-dhfr/F1,pSV2/N2,pSV2-dhfr/F3,pSV2-dhfr/P4,pSV2-dhfr/G1和pSV2-dhfr/G3。将它们分别转染导入COS-7细胞,结果表明6种转移载体质粒转染的细胞上清液都有明显的EPO活性。人EPO cDNA基因转移载体质粒在COS-7细胞中的表达水平高于人次全EPO基因组转移载体质粒。     

Cloning and Characterization of a Soluble Kynurenine Aminotransferase from Rat Brain: Identity with Kidney Cysteine Conjugate β-Lyase

Abstract: In this study, we describe the cloning and characterization of a soluble form of kynurenine aminotransferase (KAT, EC 2.6.1.7) present in rat brain. Soluble KAT was purified from rat kidney and the amino acid sequences of four tryptic peptides determined. These peptides were found to belong to the amino acid sequence reported for rat kidney soluble cysteine conjugate β-lyase, indicating that rat kidney KAT and β-lyase represent the same molecular entity. Oligonucleotide probes derived from the β-lyase cDNA were then used as primers for PCR of reverse-transcribed rat brain poly(A)⁺ RNA. After subcloning of the resulting PCR fragment and sequencing of the isolated rat brain clone, its oligonucleotide sequence was found to be identical to that reported for the β-lyase cDNA. Further evidence that the isolated rat brain clone encoded for KAT was obtained by transfecting HEK-293 cells with a construct containing the coding sequence for the enzyme. The transfected cells exhibited KAT activity and, in the presence of 2 m M pyruvate and 2-oxoglutarate, the K _m values for l -kynurenine were 1.2 m M and 86.3 µ M , respectively. Northern blot analysis of rat kidney, liver, and brain RNA revealed a single species of KAT/β-lyase mRNA of ∼2.1 kb.     

小鼠新分泌蛋白基因mBolA1的克隆与鉴定

采用生物信息学工具预测与实验相结合的方法得到了一个新的小鼠分泌蛋白基因mBolA1。该基因定位于染色体3F2,cDNA全长为730bp,编码137个氨基酸的蛋白,该蛋白含有一个保守的BolA结构域,等电点为9.05。用RT-PCR方法从鼠的混合cDNA库中克隆到mBolA1。Western blot实验表明mBolA1能从瞬转的COS 7细胞中分泌到细胞培养液中。亚细胞定位显示mBolA1定位于细胞浆,且与高尔基体不共定位,提示它是个非经典分泌途径的分泌蛋白。RT PCR显示mBolA1在组织中广泛表达。它的具体功能有待进一步研究。     

禽腺病毒江苏株（JS）复制非必需片段的确定

利用PCR方法从一株Ⅰ群禽腺病毒的分离物(FAVI-JS)中扩增出其基因组的两个末端L片段和r片段、ITR片段,并分别克隆进pGEM-T easy载体,然后将L片段、r片段和ITR片段同时克隆进pHC粘粒载体中,获得质粒pHC-FAVI-r-ITR-L,再在该克隆片段中插入增强型绿色荧光蛋白(eGFP)基因,获得转移质粒载体pFAVI-eGFP.将pFAVI-eGFP转染已被该野生型Ⅰ群禽腺病毒分离物感染了的鸡胚肾细胞进行同源重组,通过无限稀释法筛选重组病毒,结果获得了表达增强型绿色荧光蛋白的重组Ⅰ群禽腺病毒rFAVI-eGFP,证明位于基因组右末端r片段和ITR片段之间的位点为病毒复制非必需区,为禽腺病毒的重组基因工程疫苗的研究奠定了基础.     

人促血小板生成素受体c-Mpl编码区全长cDNA的克隆及其稳定表达的细胞株的构建

以人HEL细胞总RNA为模板,采用RT-PCR方法扩增了人促血小板生成素受体c-Mpl编码区全长1.9kb cDNA,测序结果表明与已报道的序列一致。然后构建了c-mpl的pcDNA3表达载体pcMPL,转染不表达cmpl的K562细胞后,经G418抗性筛选,Northern blot和Southern blot检测证实获得稳定表达cmpl的细胞株。为进一步研究cMpl的生物学功能提供有用的实验材料。     

The platelet collagen receptor glycoprotein VI is a member of the immunoglobulin superfamily closely related to FcalphaR and the natural killer receptors.

We have cloned the platelet collagen receptor glycoprotein (GP) VI from a human bone marrow cDNA library using rapid amplification of cDNA ends with platelet mRNA to complete the 5' end sequence. GPVI was isolated from platelets using affinity chromatography on the snake C-type lectin, convulxin, as a critical step. Internal peptide sequences were obtained, and degenerate primers were designed to amplify a fragment of the GPVI cDNA, which was then used as a probe to screen the library. Purified GPVI, as well as Fab fragments of polyclonal antibodies made against the receptor, inhibited collagen-induced platelet aggregation. The GPVI receptor cDNA has an open reading frame of 1017 base pairs coding for a protein of 339 amino acids including a putative 23-amino acid signal sequence and a 19-amino acid transmembrane domain between residues 247 and 265. GPVI belongs to the immunoglobulin superfamily, and its sequence is closely related to FcalphaR and to the natural killer receptors. Its extracellular chain has two Ig-C2-like domains formed by disulfide bridges. An arginine residue is found in position 3 of the transmembrane portion, which should permit association with Fcgamma and its immunoreceptor tyrosine-based activation motif via a salt bridge. With 51 amino acids, the cytoplasmic tail is relatively long and shows little homology to the C-terminal part of the other family members. The ability of the cloned GPVI cDNA to code for a functional platelet collagen receptor was demonstrated in the megakaryocytic cell line Dami. Dami cells transfected with GPVI cDNA mobilized intracellular Ca(2+) in response to collagen, unlike the nontransfected or mock transfected Dami cells, which do not respond to collagen.     

人EYA3基因真核表达载体的构建及其活性检测

目的：构建带myc标签的人EYA3基因真核表达载体,获得myc-EYA3融合表达蛋白,并对其功能进行初步检测。方法：采用PCR技术从乳腺文库中扩增人EYA3基因,并将其正确插入pXJ-40-myc载体;将重组质粒与空载体分别转染人乳腺癌细胞系ZR75-1后,Western印迹检测表达情况,并进行生长曲线实验。结果：双酶切和测序鉴定表明,myc-EYA3真核表达质粒构建成功,转染ZR75-1细胞后成功表达;生长曲线实验结果表明,EYA3可促进乳腺癌细胞的生长。结论：构建了带myc标签的人EYA3基因真核表达载体,myc-EYA3能在乳腺癌细胞ZR75-1中表达,且能促进该细胞的生长,本实验为进一步研究EYA3在乳腺癌中的功能奠定了基础。