Objective To prepare rabbit polyclonal antibody against mouse IQ and ubiquitin-like domain-containing protein (IQUB) and detect its expression in the mouse testis. Methods Full-length coding sequence of IQUB was inserted into the pET-30a(+) vector to construct pET-30a-IQUB recombinant prokaryotic plasmid. Transformation of pET-30a-IQUB plasmid into E. coli BL21 was performed, and protein expression was induced with isopropyl-beta-D-thiogalactoside (IPTG). The protein was purified through histidine-tagged fusion protein purification column, then denatured by treatment of urea with gradient concentration. New Zealand rabbits were immunized with the denatured protein to produce IQUB polyclonal antibody. Antibody titer was detected by ELISA, and Western blot analysis and immunofluorescence assay were employed to validate the effectiveness and specificity of IQUB antibody. Results pET-30a-IQUB recombinant plasmid was constructed, and protein expression of IQUB was induced successfully with IPTG. The titer of IQUB polyclonal antibody reached 1:1 000 000. The antibody specifically recognized the endogenous IQUB protein of testis in the wild-type adult mouse. IQUB was expressed in spermatogenic cells of different stages. It was localized in the acrosome and flagellum of mature sperms. Conclusion The highly specific rabbit anti-mouse IQUB polyclonal antibody is successfully prepared, which can be used for Western blot and immunofluorescence histochemistry.
Male ; Rabbits ; Animals ; Mice ; Ubiquitins ; Escherichia coli/genetics* ; Isopropyl Thiogalactoside ; Antibodies ; Enzyme-Linked Immunosorbent Assay

Objective To prepare specific mouse monoclonal antibody (mAb) against human adenovirus type 55 Hexon protein (HAdV55 Hexon). Methods The Hexon genes of HAdV55, 3, 4, 7, 16 and 21 were chemically synthesized as templates for PCR amplification. The prokaryotic expression plasmids pET28a-HAdV55 Hexon and eukaryotic expression plasmids pCAGGS-HAdV3, 4, 7, 16, 21 and 55 Hexon were constructed respectively. The pET28a-HAdV55 Hexon plasmid was transformed into E. coli competent cell BL21 (DE3) and was induced by IPTG. After the purified inclusion body was denatured and renatured, Hexon55 protein was purified by tangential flow filtration system. pCAGGS-HAdV55 Hexon was used to immunize BALB/c mice by cupping, and HAdV55 Hexon protein was used to booster immunization. The anti-HAdV55 Hexon mAb was prepared by hybridoma technique and the titer and subclass were determined. The specificity of antibody was identified by Western blot using HEK293T cells transfected with pCAGGS-HAdV55 Hexon and by immunofluorescence assay (IFA) using BHK cells transfected with pCAGGS-HAdV55 Hexon. Both clones with high titer were selected, and the cross-reactivity of pCAGGS-HAdV3, 4, 7, 16, 21 and 55 Hexon transfected cells were analyzed by Western blot analysis and IFA. Results PET28a-HAdV55 Hexon and pCAGGS-HAdV55 Hexon, 3, 4, 7, 16 and 21 expression plasmids were successfully constructed. BL21 transformed with pET28a-HAdV55 Hexon was induced by IPTG. The HAdV55 Hexon protein was mainly expressed in the form of inclusion body. After denaturation and renaturation, the purified HAdV55 Hexon protein was obtained by ultrafiltration. Six hybridoma cell lines secreting HAdV55 Hexon mAb were obtained. The antibody subclass analysis showed that 2 strains were IgG2a subtypes and 4 strains were IgG2b. Two specific HAdV55 Hexon antibodies with high titer were obtained, and there was no cross-reactivity with HAdV3, 4, 7, 16, 21 Hexon. Conclusion The specific mice mAb against HAdV55 Hexon provides an experimental basis for establishing its antigen detection method.
Animals ; Mice ; Humans ; Adenoviruses, Human/genetics* ; Escherichia coli/genetics* ; HEK293 Cells ; Isopropyl Thiogalactoside ; Blotting, Western ; Immunoglobulin G ; Antibodies, Monoclonal ; Antibody Specificity ; Mice, Inbred BALB C

Constructing robust gene circuits is a fundamental work for synthetic biology. Bacteria with suicide gene circuit based on quorum-sensing will kill themselves in a controllable pattern upon certain cell density. In the media of different IPTG inducer concentration, we observed the growth and suicidal behavior of the Escherichia coli. Top10F' with such gene circuit, screened the mutants and determined their mutated loci. The results show that, with higher IPTG concentration, the more wild type bacteria were killed; as well the mutants emerged earlier and spread over the population more quickly. The sequence of plasmids in those mutants revealed that a transposon inserted into the luxR gene and therefore disrupted Quorum-Sensing of these individuals. Furthermore, the insertion sequence of the plasmid can solely result in the mutants escaping from suicide.
Culture Media ; chemistry ; DNA Transposable Elements ; genetics ; Escherichia coli ; genetics ; growth & development ; Gene Expression Regulation, Bacterial ; Genes, Synthetic ; genetics ; Genes, Transgenic, Suicide ; Isopropyl Thiogalactoside ; chemistry ; Mutation ; Quorum Sensing ; genetics ; Repressor Proteins ; genetics ; Trans-Activators ; genetics

OBJECTIVE: To optimize the induction condition of human NOR1 gene expression in E.coli. and purify NOR1 recombinant proteins. METHODS: A full-length cDNA of human NOR1 was inserted into the corresponding region of pET28b expression vector to yield recombinant prokaryotic expression vector pET28b-NOR1. The prokaryotic expression vector pET28b-NOR1 was introduced into the bacterial host E.coli Rosettablue(DE3). Recombinant NOR1 protein was induced at different conditions. Induction condition was optimized to obtain high yield of recombinant protein. At last, the recombinant NOR1 protein was purified by Ni-IDE chromatography resin. RESULTS: Recombinant NOR1 protein was induced by IPTG in a dose-dependent manner. Increase of kanamycin concentration and induction temperature resulted in high yield of recombinant protein. The most recombinant protein was found in inclusion bodies. The recombinant His-NOR1 protein was purified with Ni-IDE chromatography resin under denature condition. CONCLUSION IPTG, kanamycin concentration and temperature can affect the expression of recombinant NOR1 protein in pET28b system. High yield of recombinant NOR1 protein is achieved by inducing 1 mmol/L IPTG and 200 μg/mL kanamycin at 37 degree. Recombinant His-NOR1 protein with high purity is purified.
Base Sequence ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Humans ; Isopropyl Thiogalactoside ; pharmacology ; Membrane Transport Proteins ; biosynthesis ; genetics ; Molecular Sequence Data ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Tumor Suppressor Proteins ; biosynthesis ; genetics

PURPOSE: Peritoneal dialysis associated peritonitis (PD peritonitis) is an important complication in maintaining. There have been only a few reports on the clinical outcome of initial no-growth peritonitis (INGP). METHODS: We reviewed 332 episodes of PD peritonitis between January 2002 and August 2009. INGP was defined as PD peritonitis with no growth of etiologic microorganism within 3 days of peritonitis. INGP was compared with initial positive growth peritonitis (IPGP) in view of clinical manifestations and outcomes. RESULTS: We divided PD peritonitis episodes into two groups: INGP (n=90) and IPGP (n=242). Peritonitis-related mortality was 5.6% in INGP, while 0.8% in IPGP (p=0.017). Further relapse was noted in INGP (10.0%) than in IPGP (vs. 4.1%; p=0.041). Salvage antibiotics were used more frequently in INGP (21.1%) than in IPGP (vs. 11.6%; p=0.027). Odds ratio of INGP to IPGP for peritonitis-related mortality was 7.14 (95% CI 1.36-37.51; p=0.017). Growth of mycobacteria or fungi increased the risk of peritonitis-related mortality with an odds ratio of 18.11 (95% CI 2.99-109.89; p=0.013). In multivariate analysis, growth of mycobacteria or fungi was the only independent risk factor for peritonitis-related mortality with an odds ratio of 10.63 (95% CI 1.27-88.75; p=0.029). CONCLUSION: INGP revealed poorer outcome than IPGP. Higher growth rate of mycobacteria or fungi in INGP than in IPGP accounted for the poor outcome. Thus one should make vigorous efforts to detect surreptitious organism when there is no growth by 3 days, especially for the possibility of either mycobacteria or fungi.
Anti-Bacterial Agents ; Fatal Outcome ; Fungi ; Isopropyl Thiogalactoside ; Multivariate Analysis ; Mycobacterium ; Odds Ratio ; Peritoneal Dialysis ; Peritonitis ; Recurrence ; Risk Factors

The expression plasmid pET32CPS harboring SmCPS gene was transformed into E. coli BL21 trxB (DE3) resulting in recombinant strain E. coli [pET32CPS]. The induction of E. coli [pET32CPS] in different temperatures, induction time, IPTG concentrations and A600 values of E. coli were performed. The optimal expression conditions of SmCPS were characterized according to the orthogonal analysis, and the ratio of the interest protein to total proteins reached to 35.6%. The recombinant SmCPS protein purified by Ni2+ affinity chromatography column was identified by SDS-PAGE and Western blotting, and then used for rabbit immunization. The titer of the rabbit antiserum against SmCPS was about 1:24 300 after the third immunization, and could specifically recognize the antigen of SmCPS protein by Western blotting analysis. The successful preparation of polyclonal antibody against SmCPS laid a foundation for further correlative study between expression of SmCPS and the production of tanshinones in protein level.
Alkyl and Aryl Transferases ; genetics ; isolation & purification ; metabolism ; Animals ; Antibody Formation ; Escherichia coli ; metabolism ; Gene Expression ; Immune Sera ; biosynthesis ; immunology ; Isopropyl Thiogalactoside ; chemistry ; Male ; Plant Proteins ; genetics ; isolation & purification ; metabolism ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Plasmids ; Rabbits ; Recombinant Proteins ; genetics ; metabolism ; Salvia miltiorrhiza ; chemistry ; Temperature ; Time Factors ; Transformation, Genetic

To produce recombinant Maxadilan using gene engineering technology, the gene of recombinant Maxadilan which expressed in protocaryon were designed and synthesized according to the amino acid sequences of Maxadilan. The recombinant plasmid pKYB-MAX was constructed and transformed into host bacteria Escherichia coli strain ER2566. After the MAX-intein-CBD fusion protein was purified by chintin-affinity chromatography, the self-cleavage activity of the intein was induced by beta-mercaptoethanol and the recombinant Maxadilan was released from the chitin-bound intein tag. The molecular weight of peptides was determined by the laser flight mass spectrometry and the results was conformity with the theoretical value. The biological activity analysis showed that recombinant Maxadilan significantly enhanced the concentration of serum glucose.
Animals ; Base Sequence ; Escherichia coli ; genetics ; metabolism ; Insect Proteins ; biosynthesis ; genetics ; Inteins ; genetics ; Isopropyl Thiogalactoside ; pharmacology ; Molecular Sequence Data ; Recombinant Proteins ; analysis ; biosynthesis ; genetics

OBJECTIVETo clone human CCL3L1 cDNA and to express and purify the glutathione-S-transferase (GST) fusion protein and human CCL3L1 protein.

METHODSTotal RNA was isolated from breast cancer cell line MCF7. CCL3L1 cDNA including open reading frame was obtained by RT-PCR. PCR product was digested with EcoR I and cloned into the pGEX-4T-1 vector. The plasmids from positive clone was prepared and sequenced to confirm the CCL3L1 in correct fusion form. pGEX-4T-CCL3L1 was transfected to BL21 E. coli via isopropyl-beta-D-thiogalactoside (IPTG) induction to produce GST-CCL3L1 fusion protein, which was further detected by SDS-PAGE and Western blotting.

RESULTSAs shown and confirmed by restriction endonuclease digestion analysis, CCL3L1 was correctly inserted into pGEX-4T-1 vector. The expressed fusion protein had a relative molecular weight of approximately 34 kD.

CONCLUSIONGST-CCL3L1 fusion protein can be successfully expressed using appropriate vector.

Cell Line, Tumor ; Chemokines, CC ; biosynthesis ; genetics ; Cloning, Molecular ; DNA, Complementary ; genetics ; Escherichia coli ; drug effects ; genetics ; metabolism ; Female ; Genetic Vectors ; Glutathione Transferase ; biosynthesis ; genetics ; Humans ; Isopropyl Thiogalactoside ; pharmacology ; Recombinant Fusion Proteins ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction

Expression strain of des-pGlu1-brazzein was constructed and the conditions using lactose as inducer was also optimized. The Influences of three factors which were lactose concentration, induction time and inducing temperature on the growth of strain and on the yield of des-pGlul-Brazzein was analyzed in detail. The result indicated that high lactose concentration inhibit the growth of strains (P < 0.01) but made no difference on expression of target protein between 0.5%-5% (P > 0.05), Biomass would be improved as time passed (P < 0.01), but the yield of target protein didn't increase obviously at 30 degrees C compared with at 37 degrees C. Further result showed that the greater expressed level of des-pGlul-Brazzein, as high as about 20% of total cell protein, could be achieved after the strain had been induced with 0.5% lactose under 28 degrees C - 30 degrees C for 4 h.
Dose-Response Relationship, Drug ; Escherichia coli ; drug effects ; genetics ; Isopropyl Thiogalactoside ; pharmacology ; Lactose ; pharmacology ; Plant Proteins ; genetics ; Plasmids ; genetics ; Temperature ; Time Factors ; Up-Regulation ; drug effects

To get the mature peptide of human-derived neurotrophin-6 (NT-6), NT-6 gene encoding mature peptide was amplified by PCR, using the NT-6 cDNA that had been cloned as templet. The gene encoding mature peptide of NT-6 gene was cloned into pGEX1-lambdaT plasmid to construct the fusion expression vector. Expression of fusion protein in Escherichia coli was defected after induction by isopropyl beta-D-thiogalactoside(IPTG). The mature peptide of NT-6 was collected with GST fusion protein purifying kit. It was shown that a fragment of 460bp was gained by PCR. With the techniques of double-cleave and electrophoresis, the recombinant vector was identified as pGEX1-NT-6. The recombinant vector pGEX1-NT-6 transformed Escherichia coli expressed fusion protein of 41KD after induction by IPTG. Cleaved by thrombin, the mature peptide of NT-6 was obtained; its molecular weight was about 15KD. The cloning and expression of human-derived NT-6 gene encoding mature protein has provided a basis for further studies on the function and clinical application of NT-6.
Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Isopropyl Thiogalactoside ; pharmacology ; Nerve Growth Factors ; biosynthesis ; genetics ; Peptides ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification