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Objective:To obtain the high expression of Herpes Simplex Virus Type 1(HSV-1)Glycoprotein D gene. Methods:The Herpes Simplex Virus Type 1(HSV-1)Glycoprotein D(gD1) gene fragment containing dominant antigen epitopes confirmed by computer analysis was cloned by PCR technical and inserted into plasmid vector pTrxA. Then the recombinant plasmid was transformed into Rosetta. The expressed product was analyze by SDS-PAGE. Results:930 bp gene fragment was amplified by PCR as anticipated. Nucleotide sequencing showed a 100 % homology with that of the published sequence in GenBank. The molecular weight of the expressed protein was about 48kDa, Western blotting indicated that the antigenicity of the protein was good. Conclusion:The plasmid pTrxA-gd1 was constructed and a high efficiency expression of the gd1 gene from Herpes Simplex Virus Type 1(HSV-1)strain was made. The expressed product shows a good antigenicity.
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The complete coding sequences of Eya gene family was amplified by standard PCR fromhuman tissues or cells cDNA library.The product of PCR was cloned into the eukaryotic expression vector pcDNA3-FLAG,generating pcDNA3-FLAG-Eya1～4.Thenhuman embryo kidney 293T cells were transfected with the recombinant plasmids and the expression of Eya genes were identified by Western blot.Transcriptional assay using a reporter containing myogenin enhance factor indicated that expression of Eya cooperation with Six in 293T cells affected the Myogenin gene expression.The expression vectors of Eya genes were constructed and confirmed by restriction enzyme digestion and DNA sequence analysis.Transcriptional assay using a reporter containing myogenin enhance factor indicated that expression of Eya in coordination with Six in 293T cells stimulated the Myogenin gene expression.Eya proteins are transcriptional activator of Six and can improve the activity of myogenin promoter.
ABSTRACT
A novel method for quickly cloning genes with multiple DNA fragments--one step cloning technique using isoschizomer-heterotail restriction endonuclease (IHRE) is described. Up to six DNA segments are ligated by using only one restriction endonuclease in this method. Comparing with routine method,it is simple, fast, economical and generates products with higher purity and achievement. Light chain of human enterokinase, DNA multi-epitope vaccine to HSV2 have been designed and successfully constructed via this method.
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Objective:To construct mammalian cell expression vector of human leukocyte antigen C gene and express it in JAR cell and study its functions.Methods:Total cell RNA was extracted from peripheral blood mononuclear cells and the cDNA was amplified by RT PCR;the cDNA fragments were directly inserted into Pbluescript KS(+/-) and the recombinant PBS HLA C was identified by restriction endonuclease digestion and sequencing;then the plasmid of pcDNA HLA C was transfected into JAR cells.Lactate Dehydrogenase(LDH) release assay was employed to detect the cytotoxicities of NK cells proliferated in vitro against HLA C transfectants JAR cells.Results:The recombinant mammalian cell expression vectors of pcDNA3 HLA C was constructed,the sequences of the insert was identical to the published sequences encoding HLA Cw *0602 gene.Several transfected JAR clones were obtained,which expressed HLA Cw *0602 in high level and constitutively.The specific lysis was detected for NK cells stimulated by IL 2 against JAR cells and HLA C transfectants JAR cells.But both cells were resistant to freshly isolated PBL cells.Conclusion:The recombinant mammalian cell expression vectors of pcDNA3 HLA Cw *0602 was successfully constructed,JAR cells resistance to NK lysis could involve an HLA C independent mechanism.
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AIM: To clone and express the metalloproteinase domain of human von Willebrand factor-cleaving protease (vWF-cp). METHODS: The metalloproteinase domain of human vWF-cp, amplified from the plasmid containing the vWF-cp cDNA gene by using polymerase chain reaction, was cloned into pUC18, and its accuracy was verified by sequencing. Then the domain was inserted into the multiclone site of pET28a(+) and included a 6?His Tag at its amino terminal. After induced by IPTG, the recombinant protein was purified by using a Ni-NTA column and confirmed by Western blot. RESULTS: Comparison of the nucleotide sequence of our cloned domain with the GenBank sequence revealed no difference. High-level expression of the recombinant protein was yielded after 5-hour induction, which amounted to 28% of total bacteria protein in inclusion body. Western blot demonstrated that it possessed high specificity. CONCLUSION: The metalloproteinase domain of vWF-cp was high efficiently expressed in Escherichia coli. This might contribute to the further study of the relationship between its structure and function. [
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Objective] To determine the nucleotide sequence of the 3′\|termal of the RESA gene Plasmodium falciparum isolate FCC1/HN, and find out the differences of the sequences of RESA gene among isolate FCC1/HN,FC27,NF7 and Palo Alto. [Methods] 3′\|terminal fragment of RESA gene of P.falciparum isolate FCC1/HN was amplified by PCR method, then was cloned into pMD18\|T vector. The recombinant was screened and identified by BamHI+XhoI and PCR technique. The nucleotide sequence of the 3′\|terminal of the RESA gene was determined by the dideoxy chain termination method. DNASTAR and BLAST software were used to compare and analyze the RESA gene sequences among the different isolates. [Results] The 3′\|termal fragment of the RESA gene with about 846 bp was specifically amplified by PCR, the recombinant pMD18\|T\|RESA was successfully constructed. Different degrees of diversity of the RESA gene sequences were found among P.falciparum isolates FCC1/HN、FC27,NF7 and Palo Alto. [Conclusion] There were differences in the sequences of RESA gene among the P.falciparum isolate FCC1/HN and three other isolates (FC27,NF7 and Palto alto).
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Alpha-toxin gene was amplified from chromosomal DNA of Clostridium perfringens type C by polymerase chain reaction(PCR). PCR product was inserted into vector pGEM-T directively. The cloned recombinant plasmid pXCPA1 possesses positive nucleotide sequence of alpha-toxin. A 1.2 kb alpha-toxin gene fragment was cleaved with restriction endonucleases NcoI/EcoRI from plasmid pXCPA1, and then inserted into an expression vector pET-28c which cleaved with NcoI/EcoRI by blunt-end ligation. The recombinant expression plasmid pETXA1 was studied in detail by restriction endonucleases analysis and nucleotide sequencing. The results showed that the recombinant expression pETXA1 possessed a positive alpha-toxin gene sequence and reading frame. BL21(DE3) (pETXA1) could produce alpha-toxin and the expressed products were recognized by alpha-toxin monoclonal antibodies, and the expression level of the alpha-toxin proteins were about 16.28% of total cellular protein by SDS-PAGE and thin-layer gel scanning analysis.
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The L-cysteine desulfhydrase gene (cd) of Pseudomonas sp.TS1138 was amplified by PCR,and the amplified gene was recombined in the cloning vector pBluescript SKII.The 1.2kb DNA fragment containing cd was sequenced,and its homology with other desulfhydrases was blast; then the cd was cloned into the expression vector pET-21a(+), and afterward expressed by IPTG inducement.The expression protein was purified by Ni-NTA His-Bind Resin.Then the expression protein was identified by the method of activity staining of desulfhydrase, and the characterization of L-cysteine desulfhydrase and the critical role it played in the L-cysteine biosynthetic pathway were discussed.
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Objective To determine the nucleotide sequence of the LACK (Leishmania homologue of receptors for activated protein kinase C) gene of Leishmania donovani isolates from plain foci (L.d SD1) and desert foci (L.d XJ771) of China, and to find out the difference of the sequence of LACK gene with other Leishimania spp. and also the isolate from hill foci of China.. Methods. The LACK genes of L.d SD1 and L.d XJ771 were amplified by RT-PCR and cloned into pUC18 vector respectively, sequenced by the dideoxy chain termination method, then analyzed and compared with that of other isolates.. Results . The LACK genes of the two isolates were successfully cloned. Both of the 2 fragments were 942 bp in length. Comparison of the two nucleotide sequences with that of other Leishmania spp. in GenBank showed that the identities were more than 97%, and the identities of the nucleotide sequences of LACK genes of the three L.d isolates from plain, desert and hill foci of China were more than 95%.. Conclusion . High identities exist among the nucleotide sequences of LACK genes of the three L.d isolates from the three foci of China.