20 results about "Foreign protein" patented technology

The application discloses a CMV virus-like particle for producing a VLP recombinant vaccine and a preparation method thereof, the CMV virus-like particle is obtained by cloning a C-terminal G4SLPETG modified plant virus cucumber mosaic virus CMV capsid gene into a prokaryotic expression vector to obtain a recombinant expression vector, the recombinant expression vector is transfected into E. coli BL21 (DE3), and expression is obtained through the recombinant E. coli BL21 (DE3); and the amino acid sequence of the C-terminal G4SLPETG modified CMV is SEQ ID NO. 1. Test proves that the recombinant strain constructed by the application is stable to expression of an exogenous protein. The recombinant protein expressed by the application is used for preparing a virus-like particle for antigen coupling, the coupling efficiency is high, the antigen purity is high, the safety is good, the virus-like particle is not pathogenic to mice and other animals, and the safety evaluation is easy.

Provided are a protein for increasing the expression yield of an exogenous protein and the use thereof, wherein an ERV29 protein and a related protein, and a P180 protein and a related protein can be used as molecular chaperones to improve the expression yield of exogenous proteins such as brazzein, the ERV29 protein has an amino acid sequence as shown in SEQ ID No. 4, and the P180 protein has an amino acid sequence as shown in SEQ ID No. 6.

The present invention makes it possible to efficiently extract and purify a target foreign protein expressed using Escherichia coli from the periplasm.　A protein production method that includes steps (a)–(c).　(a) A step for introducing a gene that codes for a target foreign protein into Escherichia coli in which a gene associated with maintenance of outer membrane structure has been modified. (b) A step for culturing the Escherichia coli from (a). (c) A step for collecting the target foreign protein from the periplasmic fraction of the cultured bacterial cells.

The application discloses a copper ion-induced atypical yeast engineering bacterium and application thereof. The application relates to the technical field of biology, and provides the copper ion-induced atypical yeast engineering bacterium, which is obtained after a DNA fragment containing an ACE1 gene expression cassette (composed of a constitutive promoter, an ACE1 gene and a terminator) and a CUP1 gene expression cassette (composed of a CUP1 promoter, a CUP1 gene and a terminator) is introduced into an atypical yeast receptor bacterium. The copper ion-induced atypical yeast engineering bacterium provided by the application can efficiently express exogenous proteins such as animal-derived lactoferrin. The copper ion induction system is simple to operate, and the inducer is low in cost. In combination with the high-efficiency expression characteristics of the atypical yeast engineering bacterium, the comprehensive cost of industrialized production of lactoferrin can be significantly reduced, and the application has outstanding industrialization application potential.

The present application relates to a kind of animal-source-free complex protein hydrolysate and its preparation method, the weight percentage of the peptide segment with molecular weight less than or equal to 1000Da in the animal-source-free complex protein hydrolysate is greater than or equal to 90% in the total peptide segment of the animal-source-free complex protein hydrolysate, the weight percentage of protein is greater than or equal to 65%, the animal-source-free complex protein hydrolysate is prepared by the method comprising the raw material containing plant protein and yeast is enzymolysis.The animal-source-free complex protein hydrolysate of the present application has the natural attribute of animal-source-free, is rich in small molecule polypeptide and contains a certain amount of free amino acid, nucleotide and other components, while having the characteristics of not strictly dependent on exogenous protease, processing flexibility, product plasticity, wide application field, etc., can be used in cell culture, microbial fermentation, animal nutrition, plant nutrition and other fields.

This invention relates to a genetically engineered bacterial outer membrane vesicle and its preparation method. By using in-cell peptides to attach exogenous proteins to the surface of OMVs via peptide bonds, a variety of desired antigens can be conveniently delivered. The reaction conditions are mild, less affected by antigen size, and unlike the SpyCatcher / SpyTag system, the in-cell peptides do not remain in the mature protein after attaching the exogenous protein to the OMV surface. This invention can serve as a universal tool for simultaneously or separately displaying different antigens on the surface of OMVs.

The application discloses a plant attenuated mutant and application thereof in production of exogenous proteins, and belongs to the technical field of biology. The attenuated mutant is that the 182th amino acid lysine of a proteinase of a zucchini yellow mosaic virus auxiliary component is changed into arginine. The attenuated mutant of the zucchini yellow mosaic virus can be used for efficiently producing alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH), and the plant used for production does not appear necrosis.

This invention specifically relates to an endogenous retroviral envelope protein T_env from the rock scorpionfish (Scorpionfish schlegelii), a lentiviral vector, and their applications, belonging to the field of genetic breeding in molecular biology. The envelope protein T_env has the amino acid sequence shown in SEQ ID NO.1. Based on this protein, this invention further provides corresponding membrane fusion protein particles, a system for in vitro assembly of lentiviral particles, transformants, and related kits. This invention utilizes the T_env protein derived from bony fish to replace the commonly used VSVG protein, which can significantly improve the infection and transduction efficiency of lentiviruses in bony fish cells, thereby achieving more efficient gene delivery. Furthermore, since this protein is an endogenous Env protein from the rock scorpionfish, it can avoid the immune rejection response of the host to foreign proteins, thus also possessing the potential for application in the in vivo environment.

The application discloses a recombinant Pichia pastoris genetic engineering bacterium with high yield of lactoferrin, and simultaneously satisfies the following three modifications: overexpression of a bovine lactoferrin expression gene, mutation of an alpha mating factor signal peptide at position E86 to F, and overexpression of a PDI molecular chaperone gene. The application also discloses a construction method of the recombinant Pichia pastoris genetic engineering bacterium, and application of the recombinant Pichia pastoris genetic engineering bacterium in production of bovine lactoferrin. The 5L fermenter test result of the bacterium strain shows that the yield of exogenous protein is significantly improved, and is increased from 10.04 mg / L in a flask fermentation to 95.78 mg / L, nearly 10 times. The application is based on the Pichia pastoris system and is not related to complex culture condition change, and is low in cost and easy to enlarge. The method is not only suitable for production of bovine lactoferrin, but also provides a new modification idea for high-efficiency expression of other heterologous proteins in the yeast system.

The application discloses a polynucleotide for improving expression level of a target gene and application thereof. The polynucleotide satisfies the following sequence characteristics: containing a start codon ATG, the start codon ATG being connected with a codon GAT coding aspartic acid, the codon GAT coding aspartic acid being connected with a codon coding serine, wherein the codon coding serine comprises TCA or AGT; the polynucleotide codes at least two negative electric amino acid residues in the first 10 amino acid residues, the negative electric amino acid residues comprising one or both of glutamic acid and aspartic acid; the polynucleotide codes at least one arginine residue in the first 5 amino acid residues. The provided polynucleotide can improve the expression effect of an exogenous protein in Escherichia coli.

This invention discloses a promoter-terminator combination for *Kluyveromyces martensii*, wherein the promoter... P STF2 The nucleotides are as shown in SEQ ID NO.1, and the terminator is... T STF2 The nucleotide sequence is shown in SEQ ID NO.2. The application of the *Kluyveromyces martensii* promoter-terminator combination in driving exogenous protein expression. This invention uses transcriptome sequencing technology to screen highly expressed genes from *Kluyveromyces martensii* transcriptome sequencing data using FPKM value as an indicator, obtaining an endogenous, highly efficient promoter-terminator combination. P STF2 ‑T STF2 .through egfp The reporter gene was validated and found to have stronger transcriptional activity, making it an ideal combination of regulatory elements for the efficient expression of exogenous proteins in *Kluyveromyces martensii*. Its application to the exogenous expression of myrosinase and xylanase resulted in efficient expression of both enzymes, demonstrating the good versatility and application value of this regulatory element combination.

This application provides an engineered Pichia pastoris and its uses, wherein the expression levels of the YIP1 and / or YIF1 genes in the engineered Pichia pastoris are reduced compared to wild-type Pichia pastoris. This application is the first to discover that reducing the expression levels of YIP1 or YIF1 can optimize the secretory expression of recombinant proteins in Pichia pastoris. Therefore, this application constructs an engineered Pichia pastoris capable of highly expressing exogenous proteins. The engineered Pichia pastoris constructed in this application is suitable for increasing the expression levels of large amounts of exogenous proteins and has broad applicability. The engineered Pichia pastoris constructed in this application does not carry any resistance genes, making subsequent operations highly feasible.

The present invention relates to a protein combination affecting a yeast growth rate and an exogenous protein expression level. Knocking out gene combinations from the peptidase A1 family, peptidase M1 family, peptidase M18 family, peptidase M28 family, peptidase S54 family, peptidase S10 family, peptidase S16 family, peptidase S14 family, and peptidase S8 family, or knocking out transcriptional activators of yeast alone, can increase the yeast growth rate and increase the exogenous protein expression level.

The disclosure relates to isolated nucleic acids comprising opioid receptor promoter regions and methods and compositions comprising said isolated nucleic acids. In one aspect the invention provides an isolated nucleic acid comprising a first region that encodes a Opioid Receptor promoter (ORP) region operably linked to a second region encoding an exogenous protein; wherein the opioid receptor promoter is selected from the group consisting of a mu opioid receptor promoter (MORP), a delta opioid receptor promoter (DORP), and a kappa opioid receptor promoter (KORP).

The application belongs to the technical field of genes, and discloses a screening method for stable high expression sites of CHO cells. The method comprises the following steps: 1) extracting DNA of CHO cells integrated with lentivirus; 2) designing specific primers for the 3' LTR region of the lentivirus vector, and performing linear amplification by using single-end DPO primers; 3) purifying PCR products, and adding a linker to the 3' end of the single-stranded DNA after purification; 4) synthesizing double-stranded DNA, and purifying the double-stranded DNA; 5) taking the purified DNA as a template to perform Index PCR; 6) performing sequencing library purification, and then performing sequencing; and 7) filtering the data after sequencing, and performing bioinformatics analysis to obtain information of stable high expression integration sites. The method can be combined with site-specific integration technology to insert an expression exogenous gene at the stable high expression site found, so that a high expression cell line of an exogenous protein can be quickly and efficiently obtained.

This invention discloses a bifunctional engineered magnetotactic bacterium. The engineered magnetotactic bacterium is constructed using a recombinant PmamC-MamC-(Gly₄Ser)₃-MagLov fusion gene fragment to construct the expression plasmid pBBR1-MagLov-MamC. Using Magnetospirillum gryphiswaldense MSR-1 as a host, the recombinant expression plasmid pBBR1-MagLov-MamC is conjugated to obtain the bifunctional engineered magnetotactic bacterium MSR-1-MagLov capable of expressing the MagLov-MamC fusion protein. This invention also discloses the construction method and its applications. This invention overcomes the technical bias of exogenous proteins inhibiting magnetosome synthesis, achieving the integration of magnetotactic motility and magnetosensitive fluorescence.

A recombinant small-molecule collagen, an expression system thereof and a preparation method thereof are provided. The recombinant small-molecule collagen derived from a plurality of sources of type-III and type-XVII collagens, and successfully expresses the recombinant small-molecule collagen. The present disclosure establishes one expression system of a small-molecule collagen and a preparation method of the small-molecule collagen, and includes an engineered exclusive chassis cell, a designed tandem repeat sequence of the small-molecule collagen, and a recombinant vector. The expression system or method of the present disclosure significantly enhances the yield of the small-molecule collagen. The present disclosure avoids the cost caused by in vitro protease digestion and the risk of exogenous protein residues, while also reducing the time and cost of a subsequent purification process.