Eukaryotic expression and biological activity identification of fusion protein ABD-Fc-IL-2 / 中国生物制品学杂志

@#Objective To express the fusion protein ABD-Fc-IL-2 in eukaryotic cells and detect its biological activity. Methods The target gene SP-ABD-Fc-IL-2 was amplified by direct and overlapping PCR,and then ligated to vector pcDNA3. 1(+).The obtained recombinant plasmid pcDNA3. 1/SP-ABD-Fc-IL-2 was transiently transfected into CHO-S cells to express the fusion protein ABD-Fc-IL-2,which was purified by Protein A beads affinity chromatography. The specificity of the purified fusion protein was detected by Western blot,the biological activity was detected by CTLL-2/MTT cell proliferation colourimetry,and the interaction between ABD fragment and human serum albumin(HSA)was detected by pull down/Western blot. Results The recombinant plasmid pcDNA3. 1/SP-ABD-Fc-IL-2 was constructed correctly as identified by restriction analysis and sequencing. The purified fusion protein ABD-Fc-IL-2 showed a purity of 90% and bound specifically to mouse anti-IL-2 monoclonal antibody with the biological activity of 3. 29 × 108IU/mL. The ABD of fusion protein and HSA bound to each other. Conclusion The eukaryotic fusion protein ABD-Fc-IL-2 had high biological activity,which promoted the proliferation of CTLL-2 cells and maintained the binding ability of ABD fragment to HSA.

Prokaryotic expression and purification of CcPT1 protein from Aspongopus chinensis / 中国生物制品学杂志

@#Objective To express and purify Cc PT1 protein from Aspongopus chinensis in prokaryotic cell.Methods Thesynthesized Cc PT1 gene was cloned to vector p GEX-4T-1 to construct recombinant expression plasmid p GEX-4T1-Cc PT1,which was then transformed to competent E.coli Rosetta strain and induced by IPTG.The induction temperature(20 ℃ and37 ℃),final concentration of IPTG(0.25,0.5,0.75 and 1 mmol/L)and induction time(6,8,10,12 h)were opti-mized.The obtained protein was purified by GST protein purification system,which was then analyzed by 10% SDS-PAGEand identified by Western blot.GST tags were removed by Pre Scission Protease during purification.Results The recombi-nant protein GST-Cc PT1 was expressed in the form of inclusion body with a concentration of 0.026 9 mg/ml,of which therelative molecular mass was 29 800,consistent with the expectation.The optimum induction condition was induction withIPTG of final concentration of 0.75 mol/L for 12 h at 20 ℃.The purified protein was more than 90% in purity and boundspecifically to mouse monoclonal antibody against GST.After remove of GST tags,Cc PT1 protein showed a relative molecu-lar mass of about 2 830 and the yield was 11.15%.Conclusion A.chinensis Cc PT1 protein was expressed by prokaryoticexpression system,and the purity of Cc PT1 protein was high after purification,which laid a foundation of the in-depth studyof anticancer peptides of A.chinensis.

Prokaryotic expression and immunogenicity of hepatitis A virus capsid proteins VP1 and VP3 / 中国生物制品学杂志

@#Objective To express the capsid proteins VP1 and VP3 of hepatitis A virus(HAV) in prokaryotic cells and evaluate their immunogenicity.Methods VP1 and VP3 gene fragments were amplified by PCR,cloned into vector pETG28a to construct recombinant expression plasmids pET-G28a-VP1 and pET-G28a-VP3,which were transformed into competent E.coli BL21(DE3),induced by IPTG,and then analyzed by 12% SDS-PAGE.The target protein was purified by ion exchange chromatography,renatured and combined with several adjuvants to immunize mice.The mice were divided into VP1-MF59,VP1-AH,VP1-AP,VP1-AP-10CpG,VP1-AP-50CpG,VP3-AP,VP3-VP1-AP and PBS control groups,five for each group.Serum IgG antibody titers of mice in various groups were detected by ELISA,and serum neutralizing antibody titers of mice in VP1-AP,VP3-VP1-AP and PBS control groups were detected by rapid fluorescence focus immunosuppression experiment.Results Colony PCR and sequencing showed that the recombinant plasmids pET-G28a-VP1 and pET-G28a-VP3were constructed correctly.The recombinant proteins VP1 and VP3,with relative molecular masses of about 37 000 and26 000 respectively,mainly existed in the form of inclusion bodies,the expression levels were 18.6% and 32.4%,and the purity was 86.3% and 84.7%,respectively.The recombinant proteins VP1 and VP3 reacted specifically with rabbit anti-HAV antiserum and mouse anti-HAV-VP3 antiserum respectively.The serum IgG antibody titer of mice in VP1-AP-50CpG group was significantly higher than that in VP1-AP group(q=22.05,P <0.01),and the serum IgG antibody titer of mice in VP3-VP1-AP group was significantly higher than that in VP1-AP group and VP3-AP group(q=22.05 and 22.49 respectively,each P <0.01).Compared with PBS control group,the serum neutralizing antibody titer of mice in VP1-AP and VP3-VP1-AP group increased significantly(q=7.79 and 25.11 respectively,P<0.01) Conclusion Prokaryotic HAV capsid proteins VP1 and VP3 showed high purity and good immunogenicity,and the addition of CpG in the preparation was beneficial to enhance the immunogenicity of antigens.This study laid a foundation of the development of HAV recombinant subunit vaccine.

Analysis of Gene Recombination between HLA-B and -DRB1, HLA-DQB1 and -DPB1 Loci / 中国实验血液学杂志

OBJECTIVE@#To investigate the recombinations within the human leukocyte antigen (HLA) region in two families.@*METHODS@#Genomic DNA was extracted from the peripheral blood specimens of the different family members. HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 loci were genotyped using polymerase chain reaction-sequence specific oligonucleotide probing technique (PCR-SSO) and next-generation sequencing technique. HLA haplotype was determined by genetic analysis of the pedigree.@*RESULTS@#The haplotypes of HLA-A*11:01~C*03:04~B*13:01~DRB1*12:02~DQB1*03:01~DPB1*05:01:01G and HLA-A*03:01~C*04:01~B*35:03~DRB1*12:01~DQB1*03:01~DPB1*04:01:01G in the family 1 were recombined between HLA-B and HLA-DRB1 loci, which formed the haplotype of HLA-A*11:01~C*03:04~B*13:01~DRB1* 12:01~DQB1*03:01~DPB1*04:01:01G. The haplotypes of HLA-A *02:06~C*03:03~B*35:01~DRB1*08:02~DQB1*04:02~ DPB1*13:01:01G and HLA-A *11:01~C*07:02~B*38:02~DRB1*15:02~DQB1*05:01~DPB1*05:01:01G in the family 2 were recombined between HLA-DQB1 and HLA-DPB1 loci, which formed the haplotype of HLA-A*02:06~C*03:03~B*35:01~ DRB1*08:02~DQB1*04:02~DPB1*05:01:01G.@*CONCLUSION@#The gene recombination events between HLA-B and -DRB1, HLA-DQB1 and -DPB1 loci were found respectively in two Chinese Han families.

Construction and expression of the recombinant plasmids of truncated and normal selenoprotein S genes / 西安交通大学学报(医学版)

Objective To construct the recombinant plasmids of normal and truncated selenoprotein S genes so as to observe their biological function in vitro or in vivo.Methods We constructed the recombinant plasmids of normal and truncated selenoprotein genes by gene recombinant technology.The gene of truncated selenoprotein was coding domain sequence(CDS)fragment of mRNA;the gene of normal selenoprotein was CDS and 3'untranslated region(including Sec insertion sequence)fragment of mRNA.We confirmed the sequence of recombinant genes by sending them to a company for comparison.The recombinant plasmids of normal and truncated genes of SelS were transfected into cells by Lipofectamine 2000.After 24 hours,the expression of green fluorescent protein was observed and transfection efficiency was detected by FACS analysis.We collected the cells to isolate the total RNA by TRIzol method,and then cDNA was obtained by mRNA reverse transcription and amplified by PCR.Results The sequencing results showed that the recombinant genes were completely the same as the target genes,indicating that we constructed the plasmids successfully.The expression of green fluorescent protein could be observed and transfection efficiency was detected up to 40% by FACS analysis.PCR results showed that the target selenoprotein gene was highly expressed in the experimental group than in control group.Conclusion The truncated and normal selenoprotein S genes were successfully constructed and transfected into cells where they were highly expressed.It lays foundation for observing the biological effect of truncated and normal selenoprotein in cell line or animal body.

Construction of SHIP1 overexpressed NSCLC cell line and the effect of SHIP1 on NSCLC cell proliferation / 中国肿瘤生物治疗杂志

@# Objective: To observe the effect of SHIP1 on NSCLC cell proliferation. Methods: The CDS region of human SHIP1 gene was obtained by inquiring NCBI Gene database and was inserted into the vector pTSB-CMV-MCS-SBP-3Flag-EGFP to construct SHIP1 over-expression plasmid, which was further used to construct SHIP1 overexpression lentivirus. SHIP1 over-expressed lentiviruses were used to transfect A549, SPCA-1 and PC-9 cell lines to construct SHIP1 overexpressed NSCLC cell line. Western blotting and qRT-PCR were used to determine the protein and mRNAexpression of SHIP1. The MTT assay and Clone formation assay were used to examine the cell proliferation ability and clone formation ability of PC-9 cells overexpressed SHIP1; Western blotting was performed to examine the level of AP-1 proteins. Results: The sequencing result suggested that the SHIP1 eukaryotic over-expression plasmid was successfully constructed. A519, SPCA-1 and PC-9 cells with SHIP1 over-expression were observed to display uniform green fluorescence under fluorescent microscopy. Compared with negative control group, the mRNA and protein levels of SHIP1 were significantly increased in SHIP1 overexpressed cells (all P<0.01). The over-expression of SHIP1 suppressed the abilities of proliferation and clone formation in PC-9 cells (all P<0.01), and down-regulated the expression of p-c-Jun and FosB etc. Conclusion: The SHIP1 overexpressed NSCLC cell lines were successfully established, and the over-expression of SHIP1 suppressed the cell proliferation ability by inhibitingAP-1 proteins in NSCLC cell lines.

Progress in application of Newcastle disease virus for anti-tumor therapy / 中华实验和临床病毒学杂志

Oncolytic virus therapy is becoming a new direction for cancer treatment, which could take the advantage of the characteristic of oncolytic virus selectively replicating in cancer cells, and killing tumor cells without damaging normal cells. Compared with conventional chemotherapy or radiotherapy, it has higher specificity, fewer side effects and the ability resisting various kinds of malignant tumors. Newcastle disease virus, a typical oncolytic virus, can cause Newcastle disease in poultry. However, no serious symptoms occurred after human being infected with NDV. With the development of reverse genetics technology, it is possible to enhance the anti-tumor activity of NDV by promoting membrane fusion and apoptosis with gene recombination. The review is about the recent research progress in vitro and in vivo oncolytic experiments and clinical application of NDV at home and abroad, which aimed at providing scientific reference for the anti-tumor study of NDV in the future.

Establishment of human ApoE4 gene transfected PC12 cell line and the effect of maltol aluminum on its cell viability / 中国职业医学

OBJECTIVE: To establish a PC12 cell line with stable expression of human apolipoprotein E( ApoE4) gene by transfection with a lentiviral vector carrying human ApoE4 gene and to investigate the effect of maltol aluminum on the viability of transfected PC12 cells. METHODS: The lentiviral vector carrying human ApoE4 gene was transfected into PC12 cells. PC12 cells with overexpression of ApoE4 gene and negative control vector were obtained after puromycin screening.The mRNA relative expression of R-Apo E and( or) H-Apo E-FLAG of cells in PC12,PC12-NC and PC12-ApoE4 groups were detected by real-time fluorescent quantitative polymerase chain reaction,and the effect of cell construction was identified. PC12-ApoE4 cells and PC12 cells were exposed to maltol aluminum solution at concentrations of 0. 00,100. 00,200. 00 and 400. 00 μmol/L respectively for 24 hours,and cell viability was detected by Cell Counting Kit-8( CCK-8)assay. RESULTS: PC12-ApoE4 and PC12-NC cells under the fluorescence microscope showed fluorescence expression,suggesting that transfection was successful. The expression of PC12 cells showed no fluorescence. The relative expression of H-Apo E-FLAG gene mRNA( the median amount) of PC12-ApoE4 cells was 148. 74,which was higher than the R-Apo E gene in PC12 cells( 1. 00) and PC12-NC cells( 1. 01)( P < 0. 01). After exposure to maltol aluminum,the cell survival rates in terms of the main effect and interaction effect of dose and cell type were statistically significant( P < 0. 01),among them,the cell viabilities were decreased in the concentration range of 0. 00-400. 00 μmol/L with the dose of maltol aluminum exposure increased,showing dose-effect relationship( P < 0. 01). CONCLUSION: The cell line stably expressed human ApoE4 gene was constructed successfully. There was interaction between the effects of maltol aluminum and ApoE4 gene on the survival rate of PC12 cells,and ApoE4 gene could enhance the cytotoxicity of maltol aluminum on PC12 cells.

The cell model establishment through lentivirus transfecting fluorescent protein EYFP-H148Q/I152L / 西安交通大学学报(医学版)

Objective To establish the HeLa cell line that can stably express EYFP fluorescent protein as the model for anion channel blocker (halide ion) screening ,which lays the foundation for high throughput screening of anion channel blocker (halide ion) .Methods Through gene recombination technology ,a new lentivirus vector which can express mutant protein YFP (EYFP‐H148Q/I152L) and puromycin resistance ,was built .The mixture of lentivirus vector and packaging plasmid was transfected into 293T cells to produce lentivirus particles . After infection of HeLa cells by the lentivirus particles ,puromycin was used to screen the cells as YFP‐positive HeLa cell line .Then cell amplification was carried out after purification and efficiency of EYFP‐H148Q/I152L was further detected by Real‐time quantitative PCR (RT‐PCR) and Western blot .We then verified the activity of EYFP‐HeLa transfected cell line as a screening model of anion channel blocker .Results Gene sequencing verified that EYFP‐H148Q/I152L was successfully inserted into lentivirus vectors .RT‐PCR and Western blot results showed that the target gene was overexpressed in HeLa cells . The specific yellow fluorescence of EYFP of HeLa cells could be observed under fluorescence microscope with the efficiency of nearly 100% . I- (low permeability ) solution stimulated the opening of anion (halogen) channels ,and the yellow fluorescence was quenched by I - flow into cells . Conclusion The EYFP‐HeLa cell line can stably express EYFP yellow fluorescent protein and is sensitive to the internal flow of I - .Therefore ,it can be used as an ideal screening model of anion channel blocker (halide ion) .

Establishing a genebank for phage single-chain antibody using silicotic rats / 中国职业医学

OBJECTIVE: To establish a genebank for phage single-chain antibody for further screening the specificity of single chain fragment variable( Sc Fv) in lung tissue of silicosis rats by phage display technology. METHODS: Twenty-four specific pathogen free male SD rats were used to construct silicosis model by one-time bronchial perfusion with 1. 0 m L of silicon dioxide suspension( mass concentration,100 g / L). We took periphery blood from 6 rats 3,6,9 and 12 weeks respectively after establishing the model. The peripheral lymphocytes were mixed,and total RNA was extracted using Trizol,and c DNA was synthesized by reverse transcription. The degenerated primers were used to amplify the variable region of heavy chain( VH) gene and variable region of light chain( VL) gene by polymerase chain reaction( PCR).Then VH and VL genes were assembled to form Sc Fv by T4 DNA linker. The cloning recombinant of Sc Fv and plasmid of PCANTAB-5e were transformed into competence E. coli TG1 by calcium chloride. The Sc Fv genebank of silicosis model was constructed by M13K07 helper phage superinfection. There were 10 bacterial colonies for plasmid restriction dualenzyme digestion randomly selected for confirmation. RESULTS: Agarose gel electrophoresis showed that there were two bands of obvious 28 S and 18 S in total RNA of periphery blood lymphocytes of silicosis rats. The total RNA was intact. The size of VH gene fragment was about 400 bp,the size of VL gene fragment was about 350 bp and recombinant Sc Fv gene fragment length was about 750 bp. The helper phage was amplified and placed with double-deck agar plate and observed limpid plaque with the size of a rice grain. The phage titer was 1. 35 × 10~(16) pfu / L. The recombinant plasmids were transformed into E. coli TG1 and total bacterial count was 8. 0 × 10~9 cfu / L in resistant plate. The positive cloned plasmid PCR gel electrophoresis and double enzyme results showed a positive inserting rate of 90. 0%. The capacity of phage single-chain antibody genebank of experimental silicosis was 7. 2 × 10~9 cfu / L. CONCLUSION: The silicosis rat model with phage Sc Fv gnebank could be successfully established,and its capacity and diversity provide support for the follow-up screening.

Construction of microRNA Let-7b-mediated recombinant influenza A (H1N1) virus with mutated PB1 / 医学研究生学报

Objective Vaccination is a most effective method for the prevention of severe diseases caused by pandemic influenza and microRNA ( miRNA) mediated gene silencing has offered a novel approach to the construction of new vaccines.Our study aimed to construct a recombinant influenza A ( H1 N1 ) virus with the PB1 gene that carries the target fragment of miRNA Let-7b. Methods After comparing the sequence of the A/Nanjing/108/2009 H1N1 viral fragments with that of Let-7b, we selected PB1 as the optimal gene sequence, inserted the Let-7b binding target gene into PB1, ligated the modified fragments with pDP 2000, and named the recombinant plasmids pDP-mu-PB1 and pDP-sclb-PB1, respectively.We co-transfected the MDCK and 293T cells with the recombinant and other seven plasmids and injected the supernatant into the allantoic cavity of the chickenembryo for virus propagation, followed by detection of the virus by hemagglutination ( HA) assay and measurement of the viral titer by TCID50 .We amplified the viral cRNA by RT-PCR and identified the viruses by agarose gel electrophoresis and nucleotide sequence analysis. Results PB1 was the optimal sequence ( 83 bp -107bp) for the attenuation of viruses.The HA-titers of miRT-H1N1 and scbl-H1N1 were 1∶32 and 1∶64, and their viral loads were 4.68 ×105 and 7.94 ×104 TCID50/mL, respectively.Nucleotide sequence analysis showed the expected fragment in the rescued virus. Conclusion A recombinant strain vaccine was successfully constructed, which has laid the foundation for fur-ther assessment of virulence.

Analysis of genetic characteristics and molecular variation of human rhinovirus strains isolated in Shenzhen during 2012 / 中华微生物学和免疫学杂志

Objective To analyze the genetic characteristics and molecular variation of human rhi-novirus strains isolated in Shenzhen.Methods RNA samples were extracted from nasopharyngeal swab samples collected from influenza-like subjects in Shenzhen and analyzed by fluorescent RT-PCR.The VP4-VP2 and VP1 gene regions of human rhinovirus strains were amplified by nested RT-PCR.Clustal W and MEGA programs were used to evaluate molecular variation of the human rhinovirus strains.Results Both human rhinovirus A and B were prevalent in Shenzhen during 2012.Human rhinoviruses A was the predomi-nant pathogen, including subtypes A47, A31, A90, A18 and so on.Two recombinant strains of human rhi-noviruses A47 and A31 were detected.The mutations scattered on the VP1 protein and varied in different subtypes.The receptor binding sites ( loop BC, DE and HI) in different subtypes showed polymorphism. Five out of twenty-five drug sensitivity sites ( I121V, L123M, V167I, Y189H and H259G) showed muta-tion.Conclusion Multiple subtypes of human rhinovirus were prevalent in Shenzhen and were in a state of constant recombination and variation.

Production and phenotype identification of specific expressed green fluorescent protein in male mice germ cells / 中国比较医学杂志

Objective The aim of this study is production of organ specific animal model for studying reproductive toxicity in mice.Methods F1 generation was gotten by mating the Ddx4 -cre transgenic male mice with the Rosa26mT/mG transgenic female mice.F1 offspring and its parents phenotype was screened by molecular biological, histopathological and in vivo imaging technology.Results At molecular level, specific DNA fragment was only found in testis of F1 offspring; At the organ level, the expression of green fluorescent protein could only be observed in testis of F1 offspring; Testicular frozen sections and sperm fluorescence observation showed that green fluorescent protein were mainly expressed in the germ cell lineage such as secondary spermatocyte and spermatocyte and spermatozoon.Conclusions The production of the mice with specific germ cell expressed green fluorescent protein by Cre/loxP recombination system were built successfully.

Discovery of Human Leukocyte Antigen HLA-A/C Gene Recombination / 现代检验医学杂志

Objective To investigate the recombination events occurring between HLA-A and-C loci discovered in two Chi-nese families.Methods HLA class I (HLA-A and-B)and II (HLA-DRB1)alleles low resolution typing were typed by pol-ymerase chain reaction-sequence specific oligonucleotide,(PCR-SSO)and PCR-sequence specific primer (PCR-SSP).HLA class I and II high resolution typing was done by sequencing-based typing (SBT).Then the recombination sites were ana-lyzed by family study.Results The results indicates that the recombination events occurred in one family between A*30∶01/32∶01-C*06∶02 and another family between A*11∶01/26∶01-C*07∶06 during meiosis.The recombination both came from fathers and resulted in new HLA haplotypes that were inherited by the children.Conclusion Two HLA-A/C re-combination events occurring between HLA-A and-C loci have been found in two Chinese families,which help further study the mechanisms of HLA recombination.

Construction and identification of pcDNA3-HBsAg-p30-ROP2 expression vec-tor / 中国血吸虫病防治杂志

Objective To construct a multi-gene recombinant pcDNA3-HBsAg-p30-ROP2 expression vector and identify it preliminarily. Methods According to recombinant pcDNA3-p30-ROP2 restriction sites,HBV HBsAg gene sequences of primers were designed and synthesized to amplify target fragment,and then cloned into pcDNA3-HbsAg-p30-ROP2 expression vector. Af-ter sequencing,it was identified finally by restriction enzyme digestion and other molecular biology techniques. Results HBV HBsAg gene segment was amplified by PCR and the multi-gene recombinant pcDNA3-HBsAg-p30-ROP2 expression vector was constructed and identified to be correct as theoretical values. The PCR and restriction enzyme digestion results showed that HBsAg and p30-ROP2 gene in recombinant plasmid were confirmed by DNA sequencing. Conclusion The multi-gene recombinant pcD-NA3-HBsAg-p30-ROP2 expression vector is successfully constructed.

Angiogenic effects of recombinant thymosin beta4 in a mouse hindlimb ischemia model / 동물의과학연구지

Recombinant thymosin beta4 (rTbeta4) has been reported to migrate and promote vascularization, wound-healing, and hair growth in a mouse hindlimb ischemia model of peripheral vascular disease. C57BL/6 mice (11-weeks-old) were anesthetized and an ischemic model was made by cutting the right aorta femoralis. The ischemic group was intraperitoneally administered with saline (300 microL/mouse) and the muscular administration group received rTbeta4 (150 microg in 300 microL of saline) or rTbeta4 (150 microg in 300 microL saline) to the abdominal cavity at 3-day intervals for 21 days. Myoatrophy of the ischemic group was observed compared to the normal control group. Generation of adjacent vessels was carried out in the rTbeta4 administration group compared to the ischemic group. The biopsy results showed significant fibrosis around the muscular undersurface and perimysium in the musculus quadriceps femoris of the ischemic group, whereas partial fibrosis was observed in the perimysium and endomysium in the rTbeta4 administration group. Immunostaining indicated that expression levels of hypoxiainducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor-1 (VEGF-1), and endothelial nitric oxide synthase (eNOS) in the rTbeta4 group were higher than those of the ischemic group. Western blotting showed that expression levels of HIF-1alpha, VEGF-1, and eNOS in the rTbeta4 group were higher than those of the ischemic group. In conclusion, rTbeta4 increases expression levels of HIF-1alpha, VEGF-1, and eNOS, resulting in angiogenesis.

Detection of integration frequency catalyzed by integrase using phenotypic screening method / 中华微生物学和免疫学杂志

Objective To establish a system for detecting integration frequency of antibiotic resist-ante integron.Methods We cloned integron and aadA2 gene cassette into different sites of plasmid pACYC 184,and the plasmid was transformed into E.coli BL21(DE3)containing plasmid overexpressing integrase.The positive clone was cultured overnight and then was spread on LB agar plate with or without streptomycin respectively,and with appropriate amount of bacteria.Clones after cultured overnight were counted to detect the integration frequency.Meanwhile we used positive clones in LB agar plate containing streptomycin as templates to carry out PCR.The purified PCR products were sequenced to identify the integration sites.Re-suits The integration frequency of integron capturing aadA2 gene cassette in BL21(DE3) host was 1.1 x 10-3 mainly at attI site.Conclusion This system can be used to detect integration frequency.

Cloning and Expression of the New Gene Recombinant RMBAY Against Type-2 Diabetes and Its Production Optimization / 中国生物工程杂志

Constructing prokaryotic expression vector pKY-RMBAY by gene recombination and research its optimizing productive conditions.By PCR technology synthesizing the gene of the RMBAY with preference codon of E.coli and the RMBAY gene was inserted into high efficiency expression vector pKYB-MCS.Expressed fusion proteins in E.coli ER2566 were purified with Chitin-Beads column.Fusion proteins binding on Chitin-Beads was cut on N-terminus of intein due to the induction of ?-mercaptoethanol and the target peptide RMBAY was released.The RMBAY was identified by mass spectrum.Experiment results showed RMBAY can be high efficiently expressed in E.coli ER2566,with optimizing productive conditions the yield of the RMBAY may be 6.7mg/L fermentation product and its purity is greater than 98%.The molecular weight of RMBAY is 3.887 kDa by mass spectrum and that accords with its theory value.

Construction and expression of secreting type human TRAIL gene vector mediated by hypoxia/radiation double sensitive promoter / 吉林大学学报(医学版)

Objective To construct secreting type human TRAIL(shTRAIL) gene vector pcDNA3.1-HRE/Egr1-shTRAIL mediated by hypoxia/radiation double sensitive promoter,and observe the effect of hypoxia and radiation on shTRAIL.Methods HRE upper and lower strands were gotten by chemical synthesis,double strands HRE was gotten by PCR;pMD19T-Egr1 was digested by SacⅠ and Hind Ⅲ,then Egr1 was obtained,pshuttle-shTRAIL was digested by Kpn Ⅰ and BamH Ⅰ,then shTRAIL was obtained;HRE/Egr1 double sensitive promoter mediated shTRAIL expression vector pcDNA3.1-HRE/Egr1-shTRAIL was constructed by gene recombination technique,it was identified correctlly by enzyme digestion,PCR and sequencing.A549 cells were divided into normal,hypoxia(0.1%),irradiation(6 Gy) and hypoxia + irradiation groups.Results After enzyme digestion by BamH Ⅰ and Sma Ⅰ,the fragments which lengthes were 1284 bp and 4 998 bp,2 292 bp and 3 990 bp were obtained;the vector was amplified by PCR with Egr1 and shTRAIL primer,the products which lengthes were 469 bp and 820 bp were obtained;pcDNA3.1-HRE/Egr1-shTRAIL was sequenced,the result was same to designed,this demonstrated that the construction was right.The vectors were transfected into A549 cells of adenocarcinoma of lung,the expression levels of shTRAIL mRNA and protein were increased after treated with hypoxia and radiation,it had statistically significant differences compared with normal group(P

Construction of Antisense GA cDNA Recombinant Plasmid and Its Effect on the Growth of Colon Cancer Cells / 中国医师杂志

Objective To construct the recombinant plasmid carrying antisense GA cDNA, and evaluate the effect of antisense GA gene on the biological characteristics of colon cancer cells. Methods The recombinant plasmid pcDNA3.0/GA containing antisense GA gene was constructed by gene recombination technique. The recombinant plasmid was transfected into colon cancer cells by lipofectamine. The effect of antisene GA gene on the biological characteristics of colon cancer cell line DH52 was evaluated by MTT and electron microscopy. Results The recombinant plasmid pcDNA3.0/GA was successfully constructed. The growth rate of colon cancer cells decreased, and microstructure of the cells appeared typical apoptotic changes after transfection. Conclusion Antisense GA gene could inhibit the growth of colon cancer cells possibly by suppressing GA gene expression and decreasing GA activity in the colon cancer cells.