546 results about "Secretion expression" patented technology

The invention relates to a preparation method of virus-like particles (VLPs) of Chikungunya virus (CHIKV). The method comprises the steps of: modifying genetic elements of a structural protein encoding gene C-E3-E2-6K-E1 of CHIKV, cloning the modified genetic elements into the expression vector of an insect cell, then transfecting the obtained recombined expression vector and baculovirus linear DNA respectively to an SF9 insect cell and making the cell secrete and express CHIKV VLPs. Additionally, the invention also makes preliminary studies on the immune effects of CHIKV VLPs and applicationof CHIKV VLPs in virus specific antibody detection, thus laying a foundation for research and preparation of immunological detection reagents and even vaccines based on CHIKV VLPs.

The invention relates to a vaccine production technology in the technical field of biology, in particular to a CHO cell strain which is established by utilizing a gene engineering means and is used for expressing recombinant protein PigFC-pigSCFVE2, and a preparation method and application of the recombinant protein. The recombinant fusion protein PigFC-pigSCFVE2 provided by the invention is A1) or A2) shown as follows, wherein A1) is protein of which the amino acid sequence is as shown in SEQ ID No.2, and A2) is protein which is obtained by substituting, losing and/or adding one or several amino acid residues in the amino acid sequence of the protein of the A1) and has PigFC-pigSCFVE2 activity. A monoclonal cell strain which is obtained through the method and capable of carrying out secretory expression on PigFC-pigSCFVE2 is higher in fusion protein expression quantity, fusion protein obtained through affinity separation and purification of an antibody can be combined with a monoclonal antibody, animals can be immunized, the immunity of a generated neutralizing antibody is higher than that of a present market product, the fusion protein can be used for swine classical fever preventive vaccine, and the production cost and the immunity failure loss can be reduced.

The invention discloses a bacillus subtilis chitosanase as well as a preparation method and application thereof. The invention optimizes an encoding gene of bacillus subtilis chitosanase according to the preference of pichia pastoris codon. The optimized nucleotide sequence is shown as SEQ ID NO.2. A pichia pastoris expression system is further utilized to perform efficient secretory expression on the optimized chitosanase encoding gene, so as to obtain the bacillus subtilis chitosanase with the amino acid sequence as SEQ ID NO.1. The bacillus subtilis chitosanase obtained according to the invention has higher hydrolytic activity to chitosan substrates at different degrees of deacetylation; the crude enzyme generated through shake-flask fermentation has the hydrolysis capacity of degrading 5g of chitosan by 1mL crude enzyme (0.3mg of protein), about 150mg of non-specific commercial enzyme is required for degrading the same amount of chitosan, and the efficiency is theoretically increased by 500 times; and the bacillus subtilis chitosanase has excellent industrial application prospects.

The invention relates to a host cell and a method for the host cell applied in efficient secretion expression of a recombinant protein, which belongs to the filed of microbiological engineering and fermentation engineering. The invention provides a bacillus licheniformis host cell CBB3008 which is preserved in the China Center for Type Culture Collection with the preserving number of CCTCC NO: M 208236. The invention transforms an expression plasmid of an industrial enzyme which is obtained by a gene cloning technology into the host cell to synthesize an industrial enzyme preparation in the host cell efficiently, and then secretes the synthesized enzyme protein into a culture medium efficiently through a protein secretion system of the host cell, thus the invention can guide efficient secretion production of the industrial enzyme preparation. Therefore, the invention is helpful to reduce the fermentative production cost of the industrial enzyme preparation, simplify the fermentative production process and reduce the environmental pressure of the fermentation industry. A method for host cell screening and genetic improvement of the invention can also be used for other types of host cells, in particular for the breeding of the host cells of bacillus subtilis, bacillus megaterium, bacillus pumilus, bacillus starch solution and the like.

The invention relates to a ZEN (zearalenone) degrading enzyme gene and a high-yield strain. The ZEN degrading enzyme gene comprises DNA molecules of (a), (b) or (c), wherein (a) has DNA molecules of a nucleotide sequence shown in SEQ ID NO.1; (b) hybridizes with the nucleotide sequence in (a) under a strict condition and encodes DNA molecules of protein with ZEN degrading enzyme activity; (c) has DNA molecules of a nucleotide sequence with 90% or higher of homology with the nucleotide sequence in (a) or (b). The invention establishes the high-yield strain for producing ZEN degrading enzymes through the sequences and further provides a high-density fermentation method. ZEN degrading enzymes can be subjected to efficient secretion expression through the high-yield strain with the high-density fermentation method, and ZEN can be quickly and efficiently degraded during fermentation.

The invention belongs to the technical field of food industry biology and relates to a bacillus subtilis expression vector of efficient secreting expression recombination lipoxygenase and application thereof. The vector utilizes a bacillus subtilis vector pHB201 as a framework, the pHB201 enzyme cutting site is modified first through an enzyme cutting method to obtain a pHB-hc vector, composition type strong promoter P43, composition type strong promoter PamyE, molecular chaperone PrsA of an Sec path and neutral protease signal peptide SnprB are obtained by cloning in bacillus subtilis 168 genome through a polymerase chain reaction (PCR), and a bacillus subtilis secretion type expression vector pHBSR is obtained in construction. Lipoxygenase gene obtained from anabaenagenome DNA in amplification is inserted into autonomously constructed expression vector pHBSR and then electrically converted into a bacillus subtilis host WB800 to achieve secreting expression of the recombination lipoxygenase, and the largest enzyme activity in fermentation liquid can reach 76U/ml.

The invention discloses a preparation method of multi-copy high expressed recombined plectasin by pichia pastoris. The method comprises the following steps: a plectasin expressing gene sequence is designed according to preference performance to codon translated by pichia pastoris; the optimized plectasin gene is fused on an alpha-factor signal peptide C terminus of an expression vector pPICZalphaA to construct a single-copy expression vector, the vector comprises a plectasin expression cassette containing a start signal element alcohol oxygen dehydrogenase strong promoter (AOX), alpha-factor signal peptide gene and a plectasin gene fused in C terminus, a stop signal element AOX (TT) and the like. A complementation principle of restriction endonuclease Bg1II and BamHI cohesive end is used to obtain plectasin gene-containing recombinant plasmid of different copy cascade expression cassettes, pichia pastoris is electrotransformed and secreted and expressed plectasin with high efficiency under the methanol induction. The expression level and plectasin gene copy number exist a linear relation. The constructed multi-copy high expressed yeast cells can be used for raising the output and reducing the cost, and is adapted to large scale production of plectasin.

The invention discloses an engineered Saccharomyces cerevisiae producing heat-stability recombinant trypsin, and its application, and belongs to the genetic engineering field. A trypsin gene obtained through in-vitro amplification is fused with a leading short peptide YVEF, and is wholly connected to a Pichia pastoris GS115 chromosome to construct engineered Saccharomyces cerevisiae efficiently secreting and expressing recombinant trypsin, and the recombinant trypsin having an improved stability is obtained after purification, and the heat stabilities of the recombinant trypsin at 40DEG C, 50DEG C and 60DEG C are 1.77, 2.6 and 31 times wild trypsin respectively, so the problem of the low stability of trypsin is solved. The production of trypsin through applying the engineered Saccharomyces cerevisiae has the advantages of high output, simple technology, intelligible heredity and application background of engineered Saccharomyces cerevisiae, and convenient industrial application.

The invention discloses a preparation method for insulin aspart through recombinant expression by using yeast, and concretely relates to a preparation method for insulin aspart through recombinant expression by using pichia yeast. Concretely, the method comprises the following technological process: effectively secreting and expressing human aspart proinsulin, performing lysyl endopeptidase single enzyme digestion to obtain insulin aspart deleting B30, coupling with a threoninate, and performing deprotection, anti-phase purification and crystallization. The method is relatively suitable for industrialized preparation of recombinant insulin aspart.

The invention discloses a porcine epidemic diarrhea S1 protein fusion gene, recombinant bacillus megaterium strain and application. An antigen fusion gene shown as SEQ ID No. 1. is obtained by connecting an antigen locus of porcine epidemic diarrhea virus (PEDV) S glycoprotein and a cell wall anchoring sequence. The invention further constructs a secretion expression vector containing the antigen fusion gene, and secretion expression vector is converted into the bacillus megaterium to express recombinant protein on the cell wall or surface of the bacillus megaterium. Immunoblotting experiments indicate that the expressed recombinant protein can react with PEDV immune serum and has the same antigenicity as PEDV natural antigens. Immunofluorescent tests of live bacteria which are subjected to induced expression indicate that the expressed recombinant protein is positioned to the surfaces of the bacteria. Experiment results indicate that the recombinant protein can be prepared into safe and effective mucous immune live vaccines for preventing and treating porcine epidemic diarrhea.

The invention provides a method for culturing microzyme of secretory expression proteolytic enzyme. The method is characterized in that an inorganic salt culture medium is adopted for fermenting and culturing a recombinant methylotrophic yeast. Fermentation and culture comprise the growth period of the microzyme and the secretory expression period of the proteolytic enzyme. In the secretory expression period of the proteolytic enzyme, the feed flow of methanol can be controlled in real time according to the variation of oxygen dissolved in fermentation liquid, and the PH value of the fermentation liquid is adjusted with ammonia, thus expressing the proteolytic enzyme at high efficiency. Compared with the prior art, the method for culturing the microzyme of the secretory expression proteolytic enzyme has the characteristics of low culture cost, convenient and accurate reaction control mode and high expression activity of the proteolytic enzyme.

The invention discloses a recombinant bacterium capable of high efficiently secreting and expressing natto kinase, and the recombinant bacterium can prominently increases the output of natto kinase. The recombinant bacterium is a recombinant pichia pastoris containing at least two copies of a natto kinase Pro-NK gene and a Haclp regulatory factor gene. After the recombinant bacteria carry out fermentation for 96 hours in a shake flask, the enzyme activity of the natto kinase can reach 470 IU/mL.

The invention discloses a fully-humanized anti-human interleukin 17A single-chain antibody, relates to the technical field of genetically engineered antibodies and specifically relates to a fully-humanized antibody fragment which is genetically engineered, screened, expressed and provided with special affinity with interleukin 17A (IL-17A). The genetically engineered antibody fragment is connected with a heavy chain region and a light chain region end to end by virtue of a soft connecting fragment. By constructing a great-capacity natural phage antibody library, an antibody fragment with special adsorption capacity on IL-17A is obtained by biological elutriation. The antibody fragment is constructed into a full-length antibody, so that the reaction of IL-17A on interleukin 6(IL-6) released by a human fibrosarcoma cell HT1080 can be inhibited by virtue of eukaryotic secretory expression and affinity purification. The antibody fragment disclosed by the invention can be used for detecting and treating rheumatoid arthritis.

The invention relates to lactic acid galactococcus food-grade secretion expression vector, and the preparation method and the application thereof, in particular to the lactic acid galactococcus food-grade secretion expression vector which comprises the following components: a thyA gene selection marker, replicons of plasmid pWV01, multiple cloning sites, promoter used for secretion expression, a ribosome bind site of Usp45, a signal peptide sequence of Usp45 and a partial Usp45 mature peptides coded sequence.

The present invention is expression vector to secretion express foreign gene in colibacillus or bacillus and its construction, and belongs to the field of gene engineering technology. The expression vector pBL-WZX contains one promoter sequence with function in both colibacillus and bacillus, one signal peptide sequence with function in both colibacillus and bacillus, one polyclonal site for foreign gene to be cloned, one artificially transcription termination sequence, one genetic marker for cloning selection between colibacillus and bacillus, and one DNA sequence for foreign gene to complete integration and gene copy number proliferation in the chromosome DNA of bacillus. The expression vector pBL-WZX can induce the transcription and translation of foreign gene and secrete the gene product to outside cell, and has foreign gene secretion expression interventing level up to 1 mg/mL in colibacillus and 3.1 mg/mL in bacillus separately.

The invention relates to an indirect ELISA (enzyme-linked immunosorbent assay) method for detecting a porcine reproductive and respiratory syndrome antibody, which comprises the following steps: by using a pGEX-6p-1 prokaryotic expression vector, performing tandem repeat on two epitopes to improve the antigen activity of an expressed protein, thus constructing a gene engineering bacterium BLpGEX-6p-GP5 capable of realizing secretory expression of the GP5 protein dominant antigen epitopes, wherein one epitope is a linear conservative neutralizing epitope (epitope B) of a screened PRRSV (porcine reproductive and respiratory syndrome virus) GP5 protein, which can be identified by a monoclonal antibody and can also be identified by porcine anti-PRRSV neutralizing serum, and the other epitope is a high-variability immunodominant epitope (A); and purifying and renaturing the expressed recombinant protein, and coating an ELISA plate, thus establishing the indirect ELISA method for detecting a PRRSV antibody to detect the PRRSV antibody level in porcine serum. Results show that the method has the characteristics of favorable repetitiveness and high specificity and can be used for PRRSV serological search.

The invention relates to a method for the excretive expression of a recombinant human granulocyte-colony factor (rHG-CSF) in colon bacillus. In the invention, a carrier of periplasmic cavity excretive type expression recombinant proteins can be established by adding DsbA signal peptide (SEQ ID NO:1) at the N end of an exogenous protein and using an lambadaPL promoter, the DH5alpha competent cells of the colon bacillus are converted, and the expression of the exogenous protein in the periplasmic cavity of the colon bacillus is realized by temperature induction. The method has high expression quantity and high excreting efficiency, and is suitable for effectively and stably excreting and expressing various exogenous genes.