cDNA cloning and expression of earthworm fibrinolytic enzyme component A

Earthworm fibrinolytic enzyme component A(EFEa),a protein with dual fibrinolytic activity ,is one of the major therapeutically important earthworm fibrinoltic enzyme components .The cDNA fragment encoded the mature protein was cloned from earthworm (Eisenia fetida )by the RT-PCR technique,The deduced amino acid sequence of the EFE component A show high homology with some members of serine proteases trypsin family,and the amino acid residues constituting the active sites are conserved in the EFEa as compared with the other proteins of the trypsin family ,The cDNA fragment was subcloned into the expression vector pQE31 and pMAL-c2X of E.coli.The resulting expression plasmids,pQE-efea and pMAL-efea ,were used to transform the E.coli strain M15.Recombinant protein bands corresponding with calcuated molecular witht were induced .The induced His6-EFEa fusion protein with pQE-efea was accumulated into inclusion body ,while the induced MBP-EFEa fusion protein with pMAL-efea was soluble and showed fibrinoloytic activities.     

Cloning and expression analysis of MBLL cDNA

The mbl (muscleblind) gene of Drosophila encodes a nuclear protein which contains two Cys3His motifs. The mutation of mbl gene will disturb the differentiation of all the Drosophila's photoreceptors. Primers have been designed according to human EST086139, which is highly homologous to mbl gene. Human fetal brain cDNA library has been screened and a novel cDNA clone has been obtained. The 2595 bp cDNA, designated MBLL (muscleblind-like), contains an open reading frame which encodes 255 amino acids and has 4 Cys3His motifs (GenBank Acc. AF061261). The amino acids sequence shares high homology to Drosophila's mbl. The Northern blot and RNA dot blot hybridization of 43 human adult tissues and 7 fetal tissues show that MBLL is a widely expressed gene, but the expression amounts differ in these tissues.     

人类Neuritin cDNA的克隆和表达

从人胎脑cDNA文库筛选出一条1618bp的cDNA。此cDNA含有一个426bp的最大开放阅读框,编码一个142个氨基酸的蛋白质,预测分子质量为15.3ku。与目前数据库中序列比较,该cDNA与鼠neuritin基因同源性达98％。多组织Northern blot分析显示neuritin在脑组织高度表达。neuritin cDNA的读框片段正确插入到pQE40表达载体中,获得了预期的表达产物,并初步得到了其纯化蛋白。     

皱纹盘鲍Hdh-MMP-1基因cDNA的克隆及原核表达

利用同源克隆方法和cDNA末端快速扩增(RACE)技术,从皱纹盘鲍(Haliotis discus hannai)肌肉组织中克隆得到基质金属蛋白酶-1基因(Hdh-MMP-1)cDNA全长序列(GenBank登录号:KR537291)。结果表明,Hdh-MMP-1 cDNA全长2136 bp,其中ORF长度为1551 bp,编码区含有516个氨基酸残基,预测其分子质量为58.94 ku,理论等电点为5.99。Hdh-MMP-1具有MMPs家族典型的N-端前肽区、催化区、铰链区和C-端类血红素结合区。利用SOPMA和SWISS-MODEL软件对该基因编码蛋白质高级结构进行了预测分析。氨基酸序列相似性结果显示,Hdh-MMP-1不仅与多种生物MMP-1基因具有序列相似性,且与某些软体动物和虫类的MMP-14及MMP-19也具有序列相似性。多序列比对结果显示,Hdh-MMP-1与红螺鲍、杂色鲍、美洲牡蛎的MMP-1相似性分别为95.29%、82.35%、38.85%。随后,构建了表达载体pET28a-catMMP-1,利用大肠杆菌原核表达系统,在大肠杆菌BL21 (DE3)中成功对该蛋白质催化区进行异源表达。     

Cloning and expression analysis ofMBLL cDNA

Thembl (muscleblind) gene ofDrosophila encodes a nuclear protein which contains two Cys₃His motifs. The mutation ofmbl gene will disturb the differentiation of all theDrosophila’s photoreceptors. Primers have been designed according to human EST086139, which is highly homologous tombl gene. Human fetal brain cDNA library has been screened and a novel cDNA clone has been obtained. The 2595 bp cDNA, designatedMBLL (muscleblind-like), contains an open reading frame which encodes 255 amino acids and has 4 Cys₃His motifs (GenBank Acc. AF061261). The amino acids sequence shares high homology toDrosophila’s mbl. The Northern blot and RNA dot blot hybridization of 43 human adult tissues and 7 fetal tissues show thatMBLL is a widely expressed gene, but the expression amounts differ in these tissues.     

兔生长激素cDNA克隆和表达

从兔脑下垂体中的mRNA中,利用合成引物逆转录PCR,获得了前体和成熟生长激素的cDNA,成熟生长激素的cDNA克隆在pET-3a表达载体并转化到大肠杆菌BL21(DE3 plys)中,获得了高效表达,表达量达到大肠杆菌总蛋白的40%。     

人Rab蛋白cDNA的克隆和表达

从人胎脑cDNA文库中克隆到一种新的Rab cDNA,全长920bp,以编码213个氨基酸残基,该蛋白预测的分子质量为24567u,等电点7．34,经同源比较,该cDNA与GenBank数据库中登录号为X14964的Rab蛋白有83％的相似性和76％的相同性,将该cDNA克隆到经改造的PBV220表达质粒,转化DH5a菌株诱导表达出该蛋白,取24种不同组织的总cDNA各100ng,用该基因序列设计引物作PCR,结果在胎肝组织中检测到有明显条带,表明该Rab基因相对在胎肝有高表达。     

Cloning and analysis of a cDNA encoding acetohydroxy acid isomeroreductase from G2 pea

Using cDNA representational difference analysis (cDNA RDA) method, we have successfully isolated a gene fragment whose expression was specifically induced by external GA₃ application. Screening a G2 pea cDNA library using this fragment as a probe, we obtained a 2036 bp full-length cDNA. It contains a 1746 bp open reading frame and encodes a protein of 581 amino acids with a theoretical molecular weight of 64 ku. It shares high-level sequence identity withAAIR genes from other plant species. This cDNA was cloned into expression vector and recombinantE. coli DH5α cells with remarkable AAIR enzyme activity were obtained.     

人Endostatin cDNA克隆及其在大肠杆菌中的表达

Ｅｎｄｏｓｔａｔｉｎ是一种新发现的血管生成抑制因子,具有很强的抗肿瘤活性,为了研究人Ｅｎｄｏｓｔａｔｉｎ的生物学功能和作用机制,作者从人胎肝组织中克隆到人ＥｎｄｏｓｔａｔｉｎｃＤＮＡ,然后将其插入到ｐＳＱＥ表达质粒中,转化Ｅｓｃｈｅｒｉｃｈｉａ,ｃｏｌｉ ＢＬ２１（ＤＥ３）,获得了ｐＳＱＥ－ＥＮＤ／ＢＬ２１（ＤＥ３）表达工程菌,对其诱导表达产物ｈＥｎｄｏｓｔａｔｉｎ进行了分离、纯化和复性的研究,结     

人粒细胞集落刺激因子cDNA的克隆与表达

用脂多糖诱导正常人单核细胞使产生粒细胞集落刺激因子。从诱导细胞中提取出总ＲＮＡ，以特上物经逆转录ＰＣＲ扩增出粒细胞集落刺激因子ｍＲＮＡ和ｃＤＮＡ，将其插入经改造的分泌型表达载体ｐＩＮ－ｏｍｐ Ａ，并转化受体菌Ｅ．ｃｏｌｉ。克隆的ｃＤＮＡ通过限制性酶双酶切的３＇端、５＇端及中间序列探针分子杂交鉴定，结果与预期一致。表达质粒在大肠杆菌哟ＩＰＲＴＧ诱导，粒细胞集落刺激因子被分泌到细菌的周质中。产物提取后     

波纹唇鱼神经肽Y基因的克隆及原核表达

以波纹唇鱼为实验对象,采用同源基因克隆技术和RACE技术得到神经肽Y基因的cDNA全长序列.波纹唇鱼npy的cDNA全长序列为645 bp,包含59 bp的5'UTR、300 bp的ORF和286 bp的3'UTR.分子进化的比对分析表明,波纹唇鱼NPY前体与斜带石斑鱼和锯隆头鱼的亲缘关系最近.波纹唇鱼ORF编码99个氨基酸,NPY前体多肽包括:信号肽、成熟肽、Gly-Lys-Arg翻译后加工位点和羧基末端侧翼肽段(CPON).该NPY前体的预测分子质量为11.27 kD,理论等电点为5.51.采用pET-32a(+)原核表达系统构建波纹唇鱼npy基因的原核表达重组子pET-32a(+)-NPY,并获得重组菌株.对重组蛋白表达菌株进行培养条件优化,结果表明:该菌株在30℃,0.6 mmol/L IPTG,培养时间8 h的条件下,重组蛋白的表达效率最高.     

棉花类耐盐锌指蛋白基因的克隆与结构分析

从棉花花瓣cDNA文库中随机挑选部分克隆，经测序发现一个与拟南芥耐盐锌指蛋白基因同源的cDNA(CSTZ),CSTZ序列全长1012bp，开放阅读框共编码272个氨基酸，含典型的植物双锌指（Cys2/His2)结构区，Northern杂交证实，CSTZ的表达随棉花幼苗钠盐处理浓度的升高而增强，在棉花花龄期，CSTZ基因在叶片，根，花瓣和花药组织中大量表达，在柱头组织中表达相对较弱。     

草鱼生长激素基因的克隆及原核表达研究

应用RT-PCR技术从草鱼脑垂体总RNA中克隆草鱼生长激素cDNA(cGH)，全长669bp，含开放阅读框633bp，编码210个氨基酸，分子量为23．6kDa，等电点为6．28；与已报道的草鱼GH有12个碱基、3个氨基酸残基的差异，同源性为98％．将草鱼cDNA定向插入原核表达载体pGEX-4T-1，构建了重组草鱼GH基因质粒pGEX-GcGH，经IPTG诱导，pGEX-GcGH在大肠杆菌中可表达49．6kDa的融合蛋白．     

Monitoring gene expression by cDNA array

A new method designated cDNA array was developed by hybridization of quantitatively arrayed DNA samples isolated randomly from a cDNA library with probes reverse-transcribed from mRNAs of different sources or treatments. The gene expression patterns of 1 000 randomly chosen clones from an Arabidopsis library were analyzed with green seedlings versus suspension cells and seedlings irradiated under UV light. Northern blot and sequence analysis of some differentially expressed clones confirmed the results revealed by cDNA array, indicating that this method is efficient and reliable to monitor gene expression.     

辣椒抗菌蛋白cDNA的分离与表达的初步分析

本研究从经辣椒疫霉侵染处理的辣椒叶片cDNA文库中分离获得了一个辣椒抗菌蛋白cDNA阳性克隆,其长度为255bp,含有长度为85个氨基酸的开放读码框架,与其它植物抗菌蛋白或几丁质酶有不同程度的同源性,推测为辣椒抗菌蛋白,命名为CansLTPS.cDNA-AFLP分析表明,CansLTPS的转录受UV-B照射和辣椒疫霉侵染的诱导,外源脱落酸(ABA)、乙烯(ETH)、水杨酸(SA)等可不同程度的诱导CansLTPS基因的转录,而MeJA处理对CansLTPS基因的转录表达影响不大,表明CansLTPS基因可应答生物和非生物逆境胁迫,其上游可能涉及ABA、ETH、SA等介入的信号传递途径.     

牛肠激酶催化亚基cDNA的克隆及融合表达载体的构建

肠激酶(Enterokinase,EK)是目前生物制药领域纯化重组蛋白产品时用于切割融合蛋白的首选工具酶之一．为克隆表达牛肠激酶催化亚基(EKL)编码的基因,以期应用于融合蛋白的切割与纯化,从市售肉牛十二指肠组织中提取总RNA,以RT-PCR方法扩增其cDNA片段,将此片段克隆于pUCm-T载体中进行全序列分析．结果表明克隆的cDNA与GenBank上的序列相比完全一致．随后,将目的基因片段插入pET32a融合型表达载体中．经测序证实其重组DNA5’端多克隆位点与重组片段的接口处核苷酸顺序准确无误,所表达重组蛋白经SDS-PAGE分析,相对分子质量为50kD,表达量达38％,为进一步进行Enterokinase催化亚基蛋白表达及活性研究奠定了基础．     

AtGT-3b基因克隆及原核表达与纯化

GT-3b转录因子是一个受NaCl和病原体诱导表达的GT-1-like转录因子,它能与GT-1 cis-element( GAAAAA)相互作用,促进下游基因的表达,在植物耐盐中起着重要的调节作用.通过分离了拟南芥(Arabidopsis thaliana)AtGT-3b基因,克隆到原核表达载体pCold TF中,并在大肠杆菌(Escherichia coli)BL21中进行融合表达;通过纯化得到AtGT-3b融合蛋白,以期用于研究其与GT-1顺式作用元件在体外的相互作用.