883 results about "Recombinant expression" patented technology

The invention discloses a PgEGY3 gene for improving cold resistance of pennisetum alopecuroides and increasing fresh weight of leaves and application of the PgEGY3 gene, and relates to the technical field of genetic engineering, and the nucleotide sequence of the PgEGY3 gene of the pennisetum alopecuroides is shown as SEQ ID NO.1. The invention also discloses a protein coded by the Pennisetum alopecuroides PgEGY3 gene. The invention also discloses a recombinant expression vector and a recombinant host cell comprising the Pennisetum alopecuroides PgEGY3 gene. The invention also discloses application of the PgEGY3 gene, a recombinant expression vector and a recombinant host cell in improving cold resistance and biomass of pennisetum alopecuroides. It is verified that the Pennisetum alopecuroides PgEGY3 gene can improve the cold resistance of plants, and the growth state of the plants under cold stress is remarkably improved through overexpression of the PgEGY3 gene.

The invention relates to the field of gene engineering for enhancing the cold resistance of plants, and relates to a recombinant expression vector, a recombinant strain and a primer pair of a pennisetum purpureum PpMYB2 gene, a method for improving the cold resistance of the plants and application of related materials in improving the cold resistance of the plants. One purpose of the invention is to provide application of the Pennisetum purpureum PpMYB2 gene and related materials thereof in improving the cold resistance of the plant, the amino acid sequence of the encoding protein of the Pennisetum purpureum PpMYB2 gene is as shown in SEQ ID NO.1, and the plant is arabidopsis thaliana or Pennisetum purpureum. Under the background that extreme low temperature events caused by global climate change are increasingly frequent, the cold resistance enhancing technology provided by the invention has important significance on guaranteeing the stability of agricultural production and reducing loss caused by low temperature. Through overexpression of the gene PpMYB2, the adaptability of perennial pennisetum purpureum to low-temperature stress can be remarkably improved, so that the planting range of perennial pennisetum purpureum is expanded to regions with lower temperature, and the survival and growth performance in different ecological environments is enhanced.

The invention discloses SGNH family esterase SH2 screened in a Tibetan hot spring environment and application of the SGNH family esterase SH2, and belongs to the technical field of gene engineering. According to the invention, a new SGNH family esterase gene is screened from a Tibetan hot spring environment, and recombinant expression is realized in escherichia coli. The recombinant esterase prepared by the invention has the characteristics of thermal stability, salt resistance, organic solvent resistance and the like, can be safely applied to tooth whitening or skin exfoliating products, avoids damage of traditional chemical bleaching agents to enamel, and has important application value in the fields of daily chemicals, medicines, food processing and the like.

The invention relates to the technical field of biomedicine, discloses mutant photo-induced ion channel ChR-2 protein, and further discloses a nucleic acid construct, an expression vector, a cell, related application and a computer model. The light-sensitive channel ChR2 protein mutant obtained by the invention has stronger light current, and the light-sensitive capability of the light-sensitive channel ChR2 protein mutant is at least improved by 100 times; besides, the invention also obtains a nucleotide sequence for coding the light-sensitive channel ChR2 protein mutant, constructs a recombinant expression vector, and obtains the light-sensitive channel ChR2 protein with higher expression quantity and stronger light sensitivity, and the light-sensitive channel ChR2 protein is very suitable for expression in cells of mammals (especially human); according to the invention, the rhodopsin in different channels is systematically studied by modifying the position G224 in the helix 6 of seven transmembrane helix motifs, which proves that the mutation of the position G224 in the helix 6 in WT ChR2 accelerates the photosensitivity of the channels, and the considered position is homologous in the helix 6 of the rhodopsin in different channels.

The invention discloses a novel biosynthesis path for producing 3 '-phosphoadenosine-5'-phosphosulfuric acid and application, and belongs to the technical field of bioengineering. According to the invention, through recombinant expression and purification of ribose kinase, ribose phosphate pyrophosphate kinase, ribose phosphate transferase, adenine thiotransferase, adenosine phosphate sulfate kinase and polyphosphate kinase 2, a six-enzyme cascade reaction taking ribose and adenosine as substrates in vitro is constructed, the molar conversion rate reaches 22.85%, and the escherichia coli and bacillus subtilis PAPS cell factory can be used for preparing the recombinant ribose phosphate pyrophosphate kinase, the ribose phosphate transferase, the adenine thiotransferase, the adenosine phosphate sulfate kinase and the polyphosphate kinase 2. The yield of PAPS in a 5-L fermentation tank reaches 7.60 g / L and 5.03 g / L respectively. The PAPS synthesis route provided by the invention provides an extensible, economical and efficient solution for the production of sulfated compounds.

The invention discloses a double-structural-domain recombinant human fibronectin, the sequence of which is shown as SEQ ID NO.3, and the double-structural-domain recombinant human fibronectin is formed by fusing a collagen binding structural domain and a cell binding structural domain of human fibronectin. The invention also provides a recombinant expression vector containing the protein coding gene and a host cell. The protein is efficiently expressed through eukaryotic cells and engineering bacteria escherichia coli, and a fermentation and purification process suitable for an industrial scale is established in a matched manner. Functional experiments prove that compared with commercially available fibronectin products with a single structural domain, the double-structural domain recombinant human chemical fibronectin disclosed by the invention can remarkably promote proliferation, migration, adhesion and differentiation activity of human skin fibroblasts, and has wide application potential in the fields of skin repair, skincare and biomedical materials.

The present disclosure concerns polypeptide having fumonisin esterase activity exhibiting increased fumonisin esterase activity, when measured at a temperature of at least 37° C., when compared to the control polypeptide comprising the amino acid of SEQ ID NO: 3. The polypeptides of the present disclosure include one or more amino acid variations which contribute to the increase fumonisin esterase activity. The present disclosure also includes compositions comprising the polypeptide having fumonisin esterase activity, methods for detoxifying a fumonisin mycotoxin as well as processes for making the compositions comprising the polypeptide having fumonisin esterase activity.

The invention discloses an aldehyde reductase mutant and application thereof in synthesis of a dexmethylphenidate hydrochloride intermediate, and belongs to the field of molecular biology and enzyme engineering. The aldehyde reductase mutant, polynucleotide for coding the mutant, and the recombinant expression vector can express the aldehyde reductase mutant and are used for constructing a recombinant cell or a recombinant strain for expressing the aldehyde reductase mutant. The provided aldehyde reductase mutant can catalyze 2-phenyl-2-((R)-piperidine-2)-acetaldehyde into (R)-2-phenyl-2-((R)-piperidine-2)-1-ethanol, especially improves the stereoselectivity of (R)-2-phenyl-2-((R)-piperidine-2)-1-ethanol, solves the problems of strict conditions, complex reaction and high cost in the existing synthesis method, and has a wide application prospect in the field of synthesis of (R)-2-phenyl-2-((R)-piperidine-2)-1-ethanol. Wide application prospects are realized.

The invention provides an engineered ketoreductase mutant, which comprises a polypeptide sequence, a gene sequence, a recombinant expression vector containing the gene, an engineering strain, a protein expression method of the engineering strain, and a reaction process for selectively synthesizing (R)-5, 7-difluorochroman-4-ol by using the engineered ketoreductase mutant.

The invention relates to the technical field of biology, in particular to a recombinant fusion protein, polynucleotide for coding the recombinant fusion protein, a recombinant expression plasmid containing the polynucleotide, an engineered recombinant host cell and a method for preparing target polypeptide by using the recombinant fusion protein. The recombinant fusion protein comprises tag polypeptide-target polypeptide-(linker 1-linker x-linker 2-target polypeptide) n from N terminal to C terminal, x is the number of linkers, x is 0 or 1, n is a positive integer not less than 1, the tag polypeptide is SEQ ID NO.1 or SEQ ID NO.2, the linker 1 contains a Kex2 protease enzyme cutting site and a carboxypeptidase B enzyme cutting site, and the linker 1 contains a Kex2 protease enzyme cutting site and a carboxypeptidase B enzyme cutting site. And the connecting peptide 2 contains a WELQ protease enzyme cutting site. The recombinant fusion protein disclosed by the invention is expressed in an inclusion body form, the synthesis process is simplified, the target polypeptide can be prepared with high yield and high purity by using the recombinant fusion protein disclosed by the invention, and the production cost can be reduced from multiple dimensions.

The present application relates to a pyridoxal kinase mutant, a recombinant expression vector and a microbial cell and their applications, and belongs to the technical field of biological catalysis. In order to solve the problem of low product concentration in existing enzyme catalysis, a pyridoxal kinase mutant is provided, the amino acid sequence is selected from the amino acid sequence shown in SEQ ID NO. 1, the lysine at position 229 is mutated to alanine, phenylalanine, methionine, arginine, threonine, histidine, serine, tyrosine, valine, leucine, isoleucine, proline, asparagine, aspartic acid or glutamic acid; the pyridoxal kinase mutant is used for catalyzing pyridoxal to synthesize pyridoxal phosphate, and a recombinant expression vector and a microbial cell can be further formed. The present application has good enzyme activity, high product conversion rate, high concentration of pyridoxal phosphate obtained, and the concentration of the product catalyzed by the wild-type pyridoxal kinase to phosphorylate pyridoxal is obviously improved.

The invention relates to the technical field of gene engineering, in particular to a cucumber salt-tolerant gene CsWRKY2 and application thereof. The invention provides application of a cucumber gene CsWRKY2 as shown in SEQ ID NO.1 in improvement of salt tolerance and stress resistance of plants or cultivation of salt-tolerant transgenic plants. The application comprises the following steps: constructing a recombinant expression vector containing the cucumber gene CsWRKY2 as shown in SEQ ID NO.1, transforming the recombinant expression vector into agrobacterium tumefaciens, and culturing to obtain recombinant bacteria carrying the recombinant expression vector, infecting the plant by using the recombinant bacteria carrying the recombinant expression vector; the cucumber gene CsWRKY2 is constructed into arabidopsis thaliana, so that the salt resistance of transgenic arabidopsis thaliana can be improved, and the salt resistance of cucumber hairy roots can also be improved by infecting the cucumber hairy roots with the cucumber gene CsWRKY2. And a basis is provided for breeding new stress-resistant varieties of arabidopsis thaliana and cucumbers.

The invention discloses a construction method and application of a chlamydomonas reinhardtii-sourced high-sweetness protein variant engineering algal strain, the construction method comprises the following steps: carrying out gene modification on sweeteners Thaumatin and Brazzein, optimizing preference codons of chlamydomonas reinhardtii to synthesize CrThaumatin and CrBrazzein encoding genes, cloning the encoding genes into an expression vector pGM6, introducing the recombinant expression vector into a chlamydomonas reinhardtii wild-type chlamydomonas sp. Algal strain, and carrying out high-sweetness protein variant engineering algal strain of the chlamydomonas reinhardtii-sourced high-sweetness protein variant engineering algal strain of the chlamydomonas reinhardtii. And screening by using a paromomycin resistance marker carried by the expression vector to successfully obtain an engineering algal strain. According to the present invention, the engineering strain is subjected to fermentation production to obtain the dry and stable Chlamydomonas reinhardtii powder rich in the target sweet protein, and the protein purification oral test results show that the sweet taste of the Chlamydomonas reinhardtii powder is 3-5 times of the sweet taste of the natural Thaumatin and Brazzein protein;

The invention relates to a recombinant expression cat interferon-omega gene and a preparation method and application thereof, the nucleotide sequence of the cat interferon-omega gene is as shown in SEQ ID NO.1, and the cat interferon-omega gene is obtained by introducing an Fc fusion fragment to the C terminal and / or N terminal of the natural gene sequence of the cat interferon-omega. XTEN or PAS is introduced to prolong a peptide fragment, and original glycosylation modification sites on a natural sequence are reserved. The method comprises the following steps: cloning a cat interferon-omega gene into an expression vector containing double promoters, further transfecting into a cell, carrying out stable cloning and screening, establishing a high-expression cell strain, and carrying out fermentation culture in a bioreactor. According to the invention, the cat interferon-omega gene is subjected to multiple modification and is efficiently expressed in a CHO-K1GS system, so that the protein yield, the stability and the half-life period are remarkably improved; the obtained fusion protein is high in purity and strong in activity, can obviously enhance immune response and protection effect when being matched with cat vaccines, and is good in safety.

The invention relates to an alcohol oxidase mutant and application thereof. Specifically disclosed are a mutant derived from Gloeophyllum trabeum alcohol oxidase (GtrAOX-M2), a nucleic acid encoding the alcohol oxidase mutant, a recombinant expression vector containing the nucleic acid, a recombinant expression transformant containing the recombinant expression vector, a preparation method of a recombinant alcohol oxidase catalyst, and a preparation method of the recombinant alcohol oxidase catalyst. The invention also discloses a method for catalyzing methanol to be oxidized into formaldehyde by using the alcohol oxidase, the alcohol oxidase mutant or the recombinant alcohol oxidase catalyst. The activity of the alcohol oxidase mutant provided by the invention is obviously improved compared with that of a female parent, and the enzyme is high in activity and can be heterologously expressed in escherichia coli, so that the alcohol oxidase mutant can efficiently oxidize methanol into formaldehyde and oxidize the methanol into formaldehyde by a one-carbon unit biological utilization methanol enzyme method; wide application prospects are shown in the aspect of subsequent conversion and generation of polyhydric alcohols.

The invention discloses a bispecific antibody which comprises a first protein functional region targeting CD30 and a second protein functional region targeting CD16a, the first protein functional region comprises a heavy chain variable region and a light chain variable region, the heavy chain variable region comprises HCDR1, HCDR2 and HCDR3, and the light chain variable region comprises LCDR1, LCDR2 and LCDR3. The invention also discloses nucleic acid for coding the antibody, a recombinant expression vector, a transformant, a preparation method of the antibody, an antibody drug conjugate, a pharmaceutical composition or a kit containing the antibody drug conjugate, and applications of the nucleic acid, the recombinant expression vector and the transformant in preparation of drugs for preventing and / or treating tumors. The bispecific antibody provided by the invention can effectively activate the NK cells and can effectively target human tumor cell related antigen CD30 protein, mediate the killing activity of the NK cells to target cells, and induce and further enhance the tumor inhibition effect of the NK cells to tumor cells.

The invention belongs to the technical field of plant genetic engineering, and particularly relates to application of an AhHTF1 gene in improving high temperature resistance of plants. The nucleotide sequence of the AhHTF1 gene is shown as SEQ ID NO.1. According to the invention, a recombinant expression vector pCAMBIA1307-AhHTF1 is constructed, and the recombinant expression vector is introduced into a model plant tobacco, so that a transgenic tobacco plant over-expressing the AhHTF1 is obtained. A high-temperature stress treatment experiment shows that overexpression of the AhHTF1 gene can improve the tolerance of the plant to high-temperature stress, and the AhHTF1 gene can be used for carrying out genetic improvement on the heat resistance of the plant.

The present invention relates to: a receptor tyrosine kinase like orphan receptor 1 (ROR 1) antibody or an antigen-binding fragment thereof; a nucleic acid encoding same; a recombinant expression vector carrying the nucleic acid; a host cell transinfected with the recombinant expression vector; a method for preparing the antibody or the antigen-binding fragment thereof; a bi- or multi-specific antibody bearing the antibody or the antigen-binding fragment thereof; an immune cell-engaging bi- or multi-specific antibody; an antibody-drug conjugate (ADC) in which the antibody or the antigen-binding fragment thereof is bound to a drug; a chimeric antigen receptor (CAR) containing the scFv of the antibody as an antigen-binding site of an extracellular domain; an immune cell having the chimeric antigen receptor introduced thereinto; a composition for combination therapy including the antibody or the antigen-binding fragment thereof; a composition for preventing or treating cancer; and a method for preventing or treating cancer.

The invention discloses a recombinant pichia pastoris strain as well as a construction method and application thereof, and belongs to the field of microbial fermentation. The construction method specifically comprises the following steps that pGAPZB is used as a plasmid skeleton, a recombinant expression plasmid pGAPZB-ACSec containing an ACSec gene is constructed, and the sequence of the ACSec gene is shown as SEQ ID No.1; linearizing the recombinant expression plasmid, and transforming the linearized recombinant expression plasmid into a pichia pastoris host; and screening a pichia pastoris strain capable of expressing the ACSec gene. According to the invention, the ability of pichia pastoris to grow and metabolize by utilizing acetic acid is improved, and the application potential of pichia pastoris in fermentation production and synthesis of chemical products taking acetic acid as a precursor by utilizing a cheap carbon source is shown.

The invention discloses a 5 'UTR library, a recombinant expression vector and a genetically engineered bacterium for improving the yield of folamin in pathogenic bacterium Badei and application of the 5' UTR library and the genetically engineered bacterium, and belongs to the technical field of microbial genetic engineering. The method comprises the following steps: designing an SD region based on a 16S rRNA (ribosomal Ribonucleic Acid) 3'end complementary sequence of a Buddei pathogenic bacterium XBD101 serving as an original strain, regulating and controlling the number of bases between the SD sequence and an initiation codon AUG and optimizing an UTR secondary structure to construct a library containing 14 UTR sequences, and replacing three sequences N4A, N7A and N18A with the strongest translation ability in the library to the UTR region of a folamin synthesis key gene fclC, so as to obtain the folamin peptide. And finally, the capacity upgrading of the folamin chassis strain is realized, and an important support is provided for the industrial production of agricultural antibiotics.

The invention discloses recombinant escherichia coli with high yield of N-acetylneuraminic acid and application of the recombinant escherichia coli, and relates to the technical field of biological genetic engineering. The invention relates to a recombinant escherichia coli, which is characterized in that the escherichia coli is taken as a host, and free expression of an N-acetylmannosamine epimerase gene yihS from Streptomyces xiamenensis or an N-acetylmannosamine epimerase gene ce3 from Bacteroides polymorpha and an exogenous N-acetylneuraminic acid lyase gene nano A is carried out; and carrying out recombinant expression on N-acetyl hexosamine 1-kinase nahK, a UDP-N-acetyl glucosamine pyrophosphorylase gene glmU and a UDP-N-acetyl glucosamine-2-epimerase gene neuC in the other synthetic route of the ManNAc. According to the recombinant escherichia coli with high yield of N-acetylneuraminic acid, the yield of N-acetylneuraminic acid can reach 23.08 g / L under a shake flask fermentation condition; a two-stage batch feeding strategy is adopted, the yield of N-acetylneuraminic acid in a 5L fermentation tank reaches 71.25 g / L, the molar conversion rate of GlcNAc reaches up to 57.60%, and the method has the potential of industrial application.

The invention discloses a high-flux and rapid chromatin immunoprecipitation sequencing method based on a HiBiT tag and a Tn5 enzyme, and belongs to the technical field of biology. According to the method, the high affinity characteristic of a HiBiT tag system is combined with a Tn5 enzyme in-situ library building technology, firstly, a DNA binding protein recombinant expression strain containing a HiBiT tag is constructed and subjected to induced expression, after formaldehyde crosslinking and cell lysis, an Anti-HiBiT antibody is used for rapid immunoprecipitation, and a Tn5 enzyme library is constructed; tn5 transposase is directly loaded on the magnetic beads combined with the protein and DNA fragment compound to complete fragmentation and linker connection, so that the construction of a next-generation sequencing library is quickly carried out, and the total consumed time from immunoprecipitation to the completion of library construction is less than or equal to 5 hours. Meanwhile, automatic treatment is realized through a micro experiment board (the reaction system is less than or equal to 200 microliters) and a liquid workstation, the experiment cost and the sample dosage are reduced, 48 transcription factors and 48 control samples can be synchronously treated, the efficiency is greatly improved, and an efficient tool is provided for microbial transcription regulation and control research.

The invention provides an anti-white spot syndrome virus peptide derived from litopenaeus vannamei, and belongs to the technical field of biology. The amino acid sequence of the anti-white spot syndrome virus peptide provided by the invention is as shown in SEQ ID NO.1, and the nucleotide sequence of the coding gene is as shown in SEQ ID NO.2. The invention further provides a recombinant expression vector and host bacteria containing the anti-white spot syndrome virus peptide gene, and application of the recombinant expression vector and host bacteria in anti-white spot syndrome virus drugs, vaccines, feeds and feed additives, and the recombinant expression vector and host bacteria have wide application prospects and economic benefits.

The invention discloses a method for efficiently expressing laccase by regulating endoplasmic reticulum stress reaction of coprinus cinereus, and belongs to the field of gene engineering and fermentation engineering. According to the invention, by regulating endoplasmic reticulum stress reaction action genes der1, Anhac1 and Cchac1 of filamentous fungi coprinus cinereus, recombinant extracellular expression of laccase Lcc5 is finally improved and regulated. Wherein the extracellular laccase activities of the recombinant bacteria can be respectively improved by 18%, 70% and 26% through interference of der1, overexpression of Anhac1 and overexpression of Cchac1, and the obtained extracellular laccase activities are respectively 31.4 U / mL, 45.1 U / mL and 33.6 U / mL, which is the highest level of coprinus cinereus homologous recombination expression laccase Lcc5 reported at present. The invention firstly indicates that the regulation and control of the coprinus cinereus endoplasmic reticulum stress reaction can promote the efficient expression of laccase in coprinus cinereus, and the invention further promotes the development of a coprinus cinereus expression system.

The invention discloses a preparation method of recombinant catechol-2, 3-dioxygenase and an application of the recombinant catechol-2, 3-dioxygenase. According to the invention, a novel catechol-2, 3-dioxygenase group C23O927 is identified from a constructed metagenome library, and the catechol-2, 3-dioxygenase group C23O927 is a key enzyme for catalyzing degradation of polycyclic aromatic hydrocarbon pollutants. A C23O927-pET32a (+) recombinant expression vector is constructed and converted into host bacteria, heterologous expression of target protein is achieved, and the prepared recombinase belongs to acid enzymes and has good resistance to high temperature, acid, alkali, high-concentration metal ions, organic solvents and surfactants. The recombinase provided by the invention can be used in an acidic environment, has very good enzymatic activity, can catalytically degrade various catechol compounds, can be better used for treating polycyclic aromatic hydrocarbon polluted environments, and has important significance for developing more products which can tolerate various extreme environments and efficiently catalyze degradation of polycyclic aromatic hydrocarbons.

The invention relates to a chicken beta-defensin-6 mutant based on AI aided design, a recombinant expression system and application, and relates to the technical field of gene engineering and protein engineering. The chicken beta defensin-6 mutant has the following amino acids at the following five sites: lysine at the 33rd site, lysine at the 35th site, asparagine at the 49th site, arginine at the 61st site and proline at the 65th site. The chicken beta-defensin-6 mutant has high stability, activity and solubility, compared with wild chicken beta-defensin-6, the chicken beta-defensin-6 mutant has higher antibacterial activity and expression level, an efficient and safe antibacterial substitute is provided for livestock and poultry breeding, and the chicken beta-defensin-6 mutant can be widely applied to the fields of livestock and poultry breeding, animal health care and biological preservation.

The present application relates to a kind of sulfide monooxygenase mutant and its application in esomeprazole synthesis.The sulfide monooxygenase mutant, its encoding gene, the preparation method of the recombinant expression vector containing the gene sequence, co-expression recombinant vector and recombinant expression transformant, and the application of the recombinant sulfide monooxygenase mutant catalyst in esomeprazole synthesis are specifically disclosed.Compared with other sulfide monooxygenases, the sulfide monooxygenase mutant obtained by the present application can efficiently utilize the coenzyme NADH with lower cost and higher stability to catalyze the asymmetric oxidation reaction of omeprazole sulfide, prepare esomeprazole, has the advantages of high substrate concentration, mild reaction condition, environment-friendly, simple operation, high yield, low production cost and good industrial application prospect.

The invention discloses a preparation method and application of GHK oligopeptide, and belongs to the technical field of biology. According to the method, a nucleotide sequence of the GHK polypeptide is obtained by designing tandem repeat GHK polypeptide ([GHK] 63) and combining preferred codons of bacillus subtilis to optimize a polypeptide coding gene. The GHK oligopeptide is subjected to recombinant expression in bacillus subtilis by utilizing a genetic engineering technology, the obtained recombinant protein is not easy to form an inclusion body and does not contain endotoxin, and the high-yield GHK oligopeptide is obtained after separation, purification and protease digestion treatment. According to the GHK oligopeptide preparation method provided by the invention, extra optimization treatment does not need to be carried out on tandem repeat GHK polypeptides, the yield of the GHK oligopeptide is improved, the whole production process is simplified, the cost is low, and the method is suitable for large-scale production of blue copper peptides and has wide application prospects in the fields of medicines, medical beauty and the like.

The invention relates to the field of biological medicine preparation, and particularly provides liraglutide precursor peptide tandem recombinant fusion protein, polynucleotide, recombinant expression plasmid, engineered host cell and a method for preparing target polypeptide. The recombinant fusion protein is fusion peptide-target polypeptide-(linker peptide-target polypeptide) n from the N terminal to the C terminal, n is a positive integer from 4 to 6, the fusion peptide is SEQ ID NO.1, the target polypeptide is liraglutide precursor peptide, the linker peptide comprises a spacer peptide and a protease restriction enzyme cutting site, the spacer peptide is SEQ ID NO.2, the isoelectric point of the recombinant fusion protein is 4.6-4.7, and the average hydrophilic value is-0.780--0.765. The proportion of the target polypeptide in the recombinant fusion protein is high, use of solvents under extreme conditions is avoided in the production process, the enzyme digestion efficiency is high, and the product purity and yield are high.

The invention discloses a CabHLH143 gene and application of the CabHLH143 gene in regulation and control of salt tolerance of pepper plants. The nucleotide sequence of the CabHLH143 gene is as shown in SEQ ID NO: 1, a bHLH transcription factor with a salt stress response function is coded, and the amino acid sequence is as shown in SEQ ID NO: 2. By constructing a recombinant expression vector and introducing the recombinant expression vector into a pepper plant, it is found that overexpression of the CabHLH143 can significantly improve the tolerance of the plant to salt stress, which is expressed by regulating the ratio of Na < + > / K < + >, enhancing the activity of antioxidant enzyme, promoting accumulation of proline and reducing the levels of MDA and ROS. The invention further provides a recombinant vector containing the CabHLH143 gene, a host cell, a transgenic plant, a specific primer and a detection kit, and the recombinant vector, the host cell, the transgenic plant, the specific primer and the detection kit are suitable for plant molecular breeding, gene function research and salt-tolerant variety screening and have wide application prospects.