Pyruvate phosphate dikinase (PPDK; EC 2.7.9.1) is found in certain microorganisms and plants, and catalyzes the conversion of AMP, PPi and phosphoenolpyruvate (PEP) to ATP, Pi and pyruvate. Using the genomic DNA of Microbispora rosea subsp. aerata as the template, a DNA fragment encoding the gene PPDK was amplified by PCR and inserted into the expression vector pET28a(+), yielding pET28a (+)-PPDK. The E. coli BL21 (DE3) was transformed with the pET28a (+)-PPDK. After inducing with IPTG, the E. coli BL21 (DE3) [pET28a (+)-PPDK] expressed recombinant PPDK fused to an N-terminal sequence of 6-His Tag. The molecular weight of PPDK was estimated to be 101 kD by SDS-PAGE. The PPDK was purified by His * Bind Resin affinity chromatography and ultrafiltration using 10 kD cut-off membrane. The successful application of PPDK in pyrosequencing was also demonstrated.
Actinomyces ; enzymology ; Escherichia coli ; genetics ; metabolism ; Pyruvate, Orthophosphate Dikinase ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Recombination, Genetic ; Sequence Analysis

The porcine IL-18 gene was amplified from recombinant plasmid pGEM-IL-18 by PCR, then the pPIC9K-IL-18 of fusion expression vector was constructed by inserting IL-18 fragment,and was transformed to GS115 by electroporation, multi-copy recombinant strains were screened by G418. The expression of recombinant fusion protein was induced by methanol, SDS-PAGE was used to analyze expression product, fusion protein was purified by Sephadex G-100 column, bioactivity of IL-18 was measured by MTT assays. Experiment results show fusion protein of pIL-18 secreted by GS115,expression reaches the secretion peak of 160 mg/L at 72 h. We have expressed and purified successfully the recombinant pIL-18 with obvious biological activity in Pichia pastoris.
Animals ; Electrophoresis, Polyacrylamide Gel ; Electroporation ; Interleukin-18 ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Fusion Proteins ; analysis ; biosynthesis ; genetics ; Swine

The aim of this study is to develop monoclonal antibody against human hepatocyte growth factor activator inhibitor 1 (HAI-1) for future study of HAI-1. The cDNA fragments of human hepatocyte growth factor activator inhibitor 1 (HAI-1) were subcloned to construct GST-HAI-1 fusion protein expression vectors. The vectors were transformed into E. coli and fusion protein expression was induced by IPTG. The GST-HAI-1 fusion proteins were separated on preparative SDS-PAGE and recovered by electroelution, and used to immunize BALB/c mice. Hybridomas producing monoclonal antibodies against human HAI-1 were prepared by cell fusion technique and characterized by ELISA, Western Blot and immunohistochemical staining. One hybridoma cell line, ZMC6, was obtained, which produces specific antibody against the expressed GST-HAI-1 fusion protein. The monoclonal antibody recognizes both the membrane-type and secretory-type HAI-1 proteins of colorectal tissue. The successful development of anti-HAI-1 antibody provides a powerful tool for further investigation on HAI-1's function.
Animals ; Antibodies, Monoclonal ; immunology ; Blotting, Western ; Glutathione Transferase ; genetics ; Immunohistochemistry ; Mice ; Mice, Inbred BALB C ; Proteinase Inhibitory Proteins, Secretory ; analysis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; immunology

This study was aimed to construct the soluble HLA-A*0201-PR1 complex for preparation of HLA-A*0201-PR1 tetramer. The recombinant HLA-A*0201-BSP (BirA substrate peptide) fusion protein as heavy chain and beta(2)-microglobulin (beta(2) m) as light chain were expressed highly as insoluble aggregates in Escherichia coli and then purified with gel filtration, and the final purity reached above 90%. The two subunits were refolded to form an HLA-A*0201-peptide complex by dilution method in the presence of an antigenic peptide PR1, a HLA-A2-restricted peptide from proteinase 3 (aa 169 - 177, VLQELNVTV). Refolded HLA-A*0201-PR1 complex was biotinylated using a BirA enzyme and purified by anion exchange chromatography on a Q-Sepharose (fast flow) column. The extent of reconstitution of the HLA-A*0201-PR1 complex was analyzed by HPLC gel filtration. The refolded and biotinylated products were detected by Western blot and ELISA with monoclonal antibody BB7.2 that recognized the natural conformations of HLA-A2 and streptavidin. The results showed that the refolded complex was composed of HLA-A*0201-BSP aggregate, HLA-A*0201-PR1 complex and beta(2) m, and reconstitution yields of 18% with PR1 was obtained. Refolded HLA-A*0201-PR1 complex could be confirmed by practical immunological method and biotinylated efficiently. It is concluded that the refolding and biotinylation of HLA-A*0201-PR1 complex is successfully obtained. This work provides the basis for the preparation of HLA-A*0201-PR1 tetramer.
DNA Primers ; genetics ; Escherichia coli ; genetics ; HLA-A Antigens ; analysis ; biosynthesis ; genetics ; HLA-A2 Antigen ; Humans ; Oligopeptides ; genetics ; metabolism ; Protein Binding ; Protein Folding ; Recombinant Fusion Proteins ; analysis ; biosynthesis ; beta 2-Microglobulin ; biosynthesis ; chemistry ; genetics

The delivery of transgenes to the central nervous system (CNS) can be a valuable tool to treat CNS diseases. Various systems for the delivery to the CNS have been developed; vascular delivery of viral vectors being most recent. Here, we investigated gene transfer to the CNS by intravenous injection of recombinant adenoviral vectors, containing green fluorescence protein (GFP) as a reporter gene. Expression of GFP was first observed 6 days after the gene transfer, peaked at 14 days, and almost diminished after 28 days. The observed expression of GFP in the CNS was highly localized to hippocampal CA regions of cerebral neocortex, inferior colliculus of midbrain, and granular cell and Purkinje cell layers of cerebellum. It is concluded that intravenous delivery of adenoviral vectors can be used for gene delivery to the CNS, and hence the technique could be beneficial to gene therapy.
Adenoviruses, Human/isolation & purification* ; Animals ; Blood-Brain Barrier ; Brain/virology* ; Cerebellum/cytology ; Cerebellum/virology ; Comparative Study ; Female ; Genes, Reporter ; Genetic Vectors/administration & dosage ; Genetic Vectors/isolation & purification ; Genetic Vectors/pharmacokinetics* ; Hippocampus/virology ; Inferior Colliculus/virology ; Injections, Intravenous ; Luminescent Proteins/analysis ; Luminescent Proteins/biosynthesis ; Luminescent Proteins/genetics ; Mice ; Mice, Inbred BALB C ; Neuroglia/virology ; Neurons/virology* ; Purkinje Cells/virology ; Pyramidal Cells/virology ; Recombinant Fusion Proteins/analysis ; Recombinant Fusion Proteins/biosynthesis ; Recombinant Fusion Proteins/genetics ; Tail/blood supply ; Tissue Distribution

This experimental study was aimed to construct the recombinant bisbicistronic eukaryotic expression vector containing endocrine and exocrine protein (EECP) gene associated with breast cancer and enhanced green fluorescent protein (EGFP) gene. And then we transfected it into breast cancer cells MCF-7 to detect the expression of EECP protein and study preliminary biological function of EECP gene. The EECP sequence was cloned to pBluescript II SK (+) plasmid. After restriction endonuclease reaction of pBluescript II SK(+) plasmid, the EECP fragment was cloned to pIRES2-EGFP vector forming a recombinant eukaryotic expression vector named pEECP-IRES2-EGFP. The potential vector was identified by restriction endonuclease digestion and sequencing. Correct plasmid was extracted and transfected into breast cancer cells MCF-7. The expression of EECP protein was detected by western blot analysis. Its biological function was studied by MTT and Flow-cytometry. It turns out that the recombinant eukaryotic expression vector containing EECP gene and EGFP gene was constructed successfully, and it could transfect MCF-7 cells efficiently. It can get higher expression of EECP protein and higher cell proliferation, thus providing an important and convenient tool for studying the function of EECP gene in vitro and in vivo.
Base Sequence ; Breast Neoplasms ; genetics ; pathology ; Female ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Humans ; MCF-7 Cells ; Molecular Sequence Data ; Proteins ; analysis ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Ribosomes ; chemistry ; metabolism

TNFR-Fc is an important fusion protein that has great potential in therapeutic and diagnostic applications. We developed an efficient fed-batch process for GS-CHO cells to produce TNFR-Fc. The rationale of this fed-batch process relies on the supply of sufficient nutrients to meet the requirements of cell metabolism. The optimal feed medium was designed through ration design. A metabolically responsive feeding strategy was designed and dynamically adjusted based on the residual glucose concentration determined off-line. In this process, the maximal viable cell density and antibody concentration reached above 9.4x10(6) cells/mL and 207 mg/L, respectively. Compared with the batch process, the newly developed fed-batch process increased the cell yield by 3.4 fold and the final antibody concentration by 3 fold. This fed-batch process would therefore facilitate the production of therapeutic antibody by GS-CHO cells.
Animals ; CHO Cells ; Cell Culture Techniques ; methods ; Cricetinae ; Cricetulus ; Culture Media ; Etanercept ; Glucose ; analysis ; Immunoglobulin G ; biosynthesis ; genetics ; Receptors, Tumor Necrosis Factor ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics

OBJECTIVETo clone PAK5-N terminal sequence for expression in E. coli to prepare its polyclonal antibody, and examine the role of PAK5 in dental germ cells.

METHODSBased on human PAK5 cDNA sequence, PCR primers were designed to amplify PAK5-N terminal sequence. The PCR product was cloned into the expression vector pGEX-4T-1 EcoRI/XhoI sites, and the recombinant plasmids were identified by agarose gel electrophoresis followed by DNA sequence analysis. The recombinant plasmids were transformed into E. coli BL21 and the expression of GST-fusion protein was induced by IPTG. Glutathione-Sepharose beads were used to purify GST-fusion PAK5-N-terminal fragment. Anti-PAK5 polyclonal antibody was obtained in immunizing rabbits with purified GST-PAK5 N-terminal fusion protein, and the antibodies were purified by protein A beads and used for detection of PAK5 expression in dental germ cells.

RESULTS AND CONCLUSIONSWe successfully cloned PAK5-N terminal gene fragment, and achieved protein expression, purification and production of PAK5-NT polyclonal antibody. The results of Western blotting indicated that PAK5 can be highly expressed in the dental germ cells, suggesting that PAK5 may play an important role in biological function of dental germ cells.

Animals ; Antibodies, Monoclonal ; biosynthesis ; genetics ; immunology ; Base Sequence ; Blotting, Western ; Cloning, Molecular ; Humans ; Molecular Sequence Data ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Sequence Analysis, DNA ; Tooth Germ ; cytology ; embryology ; enzymology ; p21-Activated Kinases ; biosynthesis ; genetics ; immunology

The CBD gene from Trichoderma reesei was cloned into the Corynebacterium glutamicum secretion expression vector pXMJ19-sp, in which green fluorescent protein was inserted to obtain pXMJ19-sp-GFP-CBD. After induced by 0.5 mmol/L IPTG, GFP-CBD was expressed in Corynebacterium glutamicum at high level of 200 mg/L. The GFP-CBD could be purified to high purity with cellulose column. The results indicated CBD can be successfully used in Corynebacterium glutamicum expression system and thus offer an extremely simple, effective and scalable way for production of recombinant proteins.
Base Sequence ; Cellulases ; biosynthesis ; genetics ; Cellulose ; chemistry ; genetics ; Cloning, Molecular ; Corynebacterium glutamicum ; genetics ; metabolism ; Cost-Benefit Analysis ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Molecular Sequence Data ; Protein Engineering ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Trichoderma ; genetics

OBJECTIVETo study the expression of human myofibrillogenesis regulator 1 (MR-1) gene in E. coli and obtain the MR-1 protein and its antibody for further investigation of its biological function.

METHODSExpression vectors pGEX-5X-1, pET30a (+), and pET24a (+), as well as host strain E. coli BL21 (DE3) and BL21-CodonPlus (DE3) -RIL were used for expression of MR-1. MR-1 N-terminal with GST or T7-tag or C-terminal with His-tag, separately, or N terminal with T7-tag and C terminal with His-tag, simultaneously, were fused in plasmids pGEX-5X-1, pET30a (+) , and pET24a (+). The expressed MR-1-T protein, separated and purified by preparative SDS-PAGE, was applied to immunize the rabbits. The titer of the antibody was assayed by ELISA and its immunogenicity was tested by Western blot with pcDNA3/MR-1 transfected human breast cancer cell MCF7.

RESULTSThe MR-1 protein was successfully expressed as inclusion body by fusing its N-terminal with T7-tag in E. coli BL21-CodonPlus (DE3) -RIL. MR-1 protein was purified by electro-elution from SDS-PAGE gel. Using this purified protein, polyclonal antibody in rabbit against MR-1 was essentially generated. ELISA and Western blot showed the titer of this antibody was about 1:10(5) with high immunogenicity.

CONCLUSIONSThe N-terminal fusion tag is the most important mechanism for MR-1 expression. The polyclonal antibody of the generated MR-1 protein in E. coli may be applied for its further biological function studies.

Animals ; Antibodies ; analysis ; Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Escherichia coli ; metabolism ; Female ; Genetic Vectors ; Humans ; Immunization ; Muscle Proteins ; biosynthesis ; genetics ; immunology ; Plasmids ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Transfection