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1.
应用基因工程技术,将EGF,GM-CSF基因克隆到pGEM-3Zf载体的EcoRI,BamHI位点上,再钭重组融合基因亚克隆到表达载体pBV220扔EcoRI,BamHI位点上,在大肠杆菌DH5α中进行表达,SDS-聚丙烯酰胺凝胶电泳和Western blot表明EG-FGM-CSF融全蛋白获得表达,并且具有EGF,GM-CSF免疫学活活。  相似文献   

2.
hEGF和hTGF—αN结构域与C结构域的功能差异   总被引:4,自引:0,他引:4  
用PCR的方法将人表皮生长因子和人转化生长因子-α(hTGF-α)的N结构域和C结构域互换,构造了两个嵌合分子E-TGF(EGF1-32-TGF-α34-50)和T-EGF(TGF-α1-33-EGF33-53)。野生型和嵌合分子基因在大肠杆菌phoA系统表达并纯化定量。各重组体的受体竞争结合活性大小为hEGF〉hTGF-α和E-TGF〉T0-EGF,它们的促细胞生长活性的大小为hTGF-α和E-  相似文献   

3.
雄激素受体片段(氨基酸:359 ̄732)以及糖皮质激素受体片段(氨基酸:396 ̄548)以与GST融合形式在大肠杆菌中分别表达为GST-AR和GST-GR两种融合蛋白,它们含有DNA结合结构域和一些旁侧氨基酸,凝胶阻滞分析表明能与雄激素/糖皮质激素应答元件(ARE/GRE)在体外结合。本文报道在大鼠前列腺中发现有抑制GST-AR以及GST-GR与ARE/GRE结合的因子,抑制作用与ARE/GRE来  相似文献   

4.
日本血吸虫26kD抗原基因在BCG中的表达   总被引:5,自引:0,他引:5  
研究了外源基因日本血吸虫26kD抗原(Sj26GST)在卡介苗(bacilusCalmete-Guerin,BCG)、耻垢分枝杆菌(M.smegmatis)和大肠杆菌(E.coli)中的表达.运用重组DNA和聚合酶链反应(PCR)等分子生物学技术,以表达Sj26GST的E.colipGEX衍生质粒为模板,经PCR得到编码Sj26GST的全长cDNA片段.将其按正确的阅读框顺序,克隆到人结核杆菌热休克蛋白(heatshockprotein,HSP)70的启动子下游,再将HSP70启动子和Sj26GST基因一起亚克隆到E.coli-分枝杆菌穿梭质粒pBCG-2000中,得到E.coli-分枝杆菌穿梭表达质粒pBCG-Sj26.pBCG-Sj26电转化入BCG和M.smegmatismc2155中表达Sj26GST抗原,所表达的天然重组Sj26GST(rSj26GST)为可溶性蛋白,在SDS-PAGE上分子量为26kD处可见明显的表达蛋白带.其表达量分别占BCG和M.smegmatis菌体总蛋白的15%和10%.可见,Sj26GST基因能在BCG中高效表达.  相似文献   

5.
为表达、获取日本血吸早谷胱甘肽转移酶(SjGST)基因工程重组蛋白,以日本血吸虫(中国大陆株)cDNA为模板,设计、合成特定寡核苷酸引物,RT-PCR法扩增GST编码基因序列,将扩增产物连接pGEM-T克隆载体,再亚克隆到真、原核表达质粒pBK-CMV中,转染大肠杆菌XL1-blue,经IPTG诱导后用SDS-PAGE分析表达效果。结果 RT-PCR法特异性扩增出日本血吸虫GST编码区基因片段,其  相似文献   

6.
血管内皮生长因子C的研究进展   总被引:13,自引:0,他引:13  
血管内皮生长因子C(VEGF-C)是一种特异性血管、淋巴管内皮细胞调节因子,其结构与VEGF具有同源性。VEGF-C通过受体CEGFR-2和VEGFR-3发挥作用,其mRNA的表达具有一定的组织特点,并受多种因素的调节。VEGF-C对于胚胎发育,细胞分化、活体内外血管、淋巴管内皮细胞均有重要的调节作用。  相似文献   

7.
狂犬病毒aG株糖蛋白在pET原核系统中的表达及纯化   总被引:6,自引:0,他引:6  
在狂犬病的临床诊断和基础研究中都迫切需要大量纯度高且价廉的狂犬病毒糖蛋白抗原。本文应用带有His6尾的pET原核表达系统对狂犬病毒(RV)aG株的糖蛋白(GP)进行表达和纯化。构建的融合表达载体pET-aG1和pET-aG2(-57bp)分别含有RVaG株GP基因的全序列及删除了为GP信号肽编码的58个碱基的序列。用SDS 聚丙烯酰胺凝胶电泳、免疫印迹、间接ELISA检测都证明表达产物为RVGP,且位于菌体中的包涵体内。经固定化金属螯合层析(IMAC)提纯,pET-aG1表达产物有较高的特异性和纯度,可用作测定RVGP抗体的免疫诊断试剂。  相似文献   

8.
蛇毒蛋白Echistatin的C端突变基因的构建,表达及其活性研究   总被引:1,自引:0,他引:1  
通过PCR定点突变的技术,将蛇毒蛋白Echistatin基因的C端进行了突变(Ala48→Arg48→,Thr49→Val49),模拟纤维蛋白N端的四肽(Gly-Pro-Arg-Val),以期增加Ecs(Echistatin)的活性,突变的基因重组到表达质粒pJC264上,经IPTG诱导,以CheY-Ecs融合蛋白方式进行了表达,表达量占菌体总蛋白的15 ̄20%,Sephadex G-75初步纯化  相似文献   

9.
以鲑鱼基因组DNA为模板,采用PCR获得sCT基因,并为DNA序列分析所证实.以pGEX-3X为表达载体,利用体外定点突变技术成功地构建了融合蛋白GST-sCT的重组表达质粒pGEX-3X-sCT,在大肠杆菌中得到高效表达,其表达量约为菌体总蛋白的30%;利用亲合层析法对融合蛋白GST-sCT进行纯化,再经Fac-torΧa酶切后获得了重组sCT,并对其进行活性检测.初步实验证明,重组sCT具有较强的生物活性  相似文献   

10.
利用COS7细胞暂时表达系统,研究转译起始序列对EPO-cDNA表达的影响。通过DNA重组技术,构建了原EPO-cDNA表达载体pCSV-EPO(1),其转译起始序列为5'AATTCATGG3'。同时通过定点突变技术,将起始序列改变成5'CCACCATGG3',而构建了另一表达载体PCSV-EPO(2)。后经序列分析证明无误后和前均通过DEAE-dextran法转染COS7细胞上清,测定结果为  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

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For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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