247 results about "Prokaryotic expression" patented technology

The invention discloses three pattern recognition protein Hc beta GRP genes for preventing and treating fall webworms, dsRNA and application thereof. Specifically, the nucleotide sequences of the three pattern recognition protein Hc beta GRP genes for preventing and treating fall webworms are respectively SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 3. The recombinant Hc beta GRP protein is successfully obtained through a prokaryotic expression system, an in-vitro bacteriostatic test proves that the recombinant Hc beta GRP protein, the Hc beta GRP protein and the dsRNA have direct bacteriostatic activity, dsRNA is designed based on a pattern recognition protein Hc beta GRP gene, a hyphantria cunea Hc beta GRP dsRNA interference system implemented by using an injection method is established, an obvious gene silencing effect is obtained by injecting the Hc beta GRP dsRNA interference system into hyphantria cunea, and the Hc beta GRP dsRNA interference system is applied to the hyphantria cunea. The technical support is provided for the application of the Hc beta GRP RNAi technology. Besides, the dsRNA of the hyphantria cunea Hc beta GRP is combined with the biocontrol bacteria by utilizing an established hyphantria cunea Hc beta GRP RNA interference system, so that the control effect of the biocontrol bacteria can be remarkably improved.

The invention discloses L-arabinose isomerase, engineering bacteria and application, the amino acid sequence of the L-arabinose isomerase is shown as SEQ ID NO: 3, and the gene sequence for coding the L-arabinose isomerase is shown as SEQ ID NO: 2. On the basis of a genome of a Peribacillussp.S4 strain, a gene for coding the L-arabinose isomerase is excavated, and a stable prokaryotic expression system is constructed by performing codon optimization on the gene, so that the large-scale controllable production of the L-arabinose isomerase is realized, the yield of the enzyme is remarkably increased, the production cost of the enzyme is reduced, and the method is suitable for industrial production. A stable and economical enzyme source is provided for the production of D-tagatose; the L-arabinose isomerase expressed by the constructed engineering bacteria can significantly improve the yield of D-tagatose, and industrialization of D-tagatose is facilitated.

The invention belongs to the field of biology, and particularly relates to a rhododendron molle heat shock protein RmHSP20-4 gene and application thereof. The RmHSP20-4 participates in response of rhododendron molle to high-temperature stress, and can be used for screening high-temperature tolerance germplasm of rhododendron molle and evaluating high-temperature tolerance of sheep. The gene is transferred into a prokaryotic expression strain, the growth of the transgenic strain under the stress of CdCl2 and high temperature is obviously improved, and the RmHSP20-4 gene and a protein coded by the RmHSP20-4 gene provide candidate genes for the cultivation of Rhododendron molle heavy metal resistance, high temperature stress resistance and other related varieties. A new candidate gene resource is provided for cultivating transgenic plants or microorganisms with excellent shapes such as heavy metal resistance and high temperature stress resistance, and an important reference is also provided for mining heat-resistant genes of azaleaceae plants.

The invention discloses a sheep paratuberculosis specific detection kit and application, and relates to the field of biological detection.The kit comprises an elisa plate coated with a recombinant Mycobacterium paratuberculosis membrane protein antigen, the nucleotide sequence of the recombinant Mycobacterium paratuberculosis membrane protein antigen is shown as SEQ ID NO: 1, and the amino acid sequence of the recombinant Mycobacterium paratuberculosis membrane protein antigen is shown as SEQ ID NO: 2; a confining liquid; a serum diluent; carrying out enzyme labeling on a second antibody; a TMB color developing solution and a stop solution; according to the sheep paratuberculosis specific detection kit disclosed by the invention, the recombinant Mycobacterium paratuberculosis membrane protein antigen is adopted as a core detection component, and the antigen has high specificity and can accurately identify paratuberculosis positive serum and effectively distinguish positive and negative samples; meanwhile, prokaryotic expression and purification are carried out on the specific membrane protein of the mycobacterium paratuberculosis for the first time, and a novel sheep paratuberculosis indirect ELISA diagnosis method with high sensitivity and specificity based on the protein as an antigen is established.

The application discloses an elagatis bipinnulatus IGF2 gene and application thereof, wherein the nucleotide sequence of the elagatis bipinnulatus IGF2 gene is shown as SEQ ID NO:1, the amino acid sequence of the protein coded by the IGF2 gene is shown as SEQ ID NO:2. A prokaryotic expression vector containing the gene and a corresponding recombinant strain are successfully constructed, a recombinant IGF2 protein is prepared through a high-efficiency expression system, and the recombinant IGF2 protein is applied to preparation of a product for regulating fish feeding, preparation of an additive with the function of promoting fish feeding and preparation of artificial feed with the function of promoting fish feeding. The recombinant IGF2 protein can significantly enhance the expression of feeding-related genes of the elagatis bipinnulatus and significantly improve the feeding amount.

The invention belongs to the technical field of biological detection, and particularly relates to a preparation method of lipopolysaccharide-beta-1, 3-glucan binding protein and application of the lipopolysaccharide-beta-1, 3-glucan binding protein in preparation of a broad-spectrum colloidal gold detection product for dermatophytes. The prokaryotic expression system induces the procambarus clarkii-sourced lipopolysaccharide-beta-1, 3-glucan binding protein to be efficiently expressed in an inclusion body form, the optimized inclusion body purification-renaturation process is combined to realize batch preparation, and the colloidal gold chromatography technology is integrated, so that the procambarus clarkii-sourced lipopolysaccharide-beta-1, 3-glucan binding protein is obtained. The bottlenecks of the traditional detection method in sensitivity, broad spectrum and field applicability are broken through.

The invention provides a subunit vaccine composition for porcine epidemic diarrhea, porcine delta coronal and porcine rotavirus as well as a preparation method and application of the subunit vaccine composition, and is characterized in that the subunit vaccine composition comprises prokaryotically expressed swine erysipelas filamentous bacillus SpaA protein, viral subunit protein and pharmaceutically acceptable adjuvants; wherein the amino acid sequence of the prokaryotically expressed swine erysipelas filamentous bacillus SpaA protein is as shown in SEQ No.1, and the viral subunit protein is selected from one or more of porcine epidemic diarrhea virus S protein, porcine delta coronavirus S protein and porcine rotavirus VP8 protein. The vaccine composition disclosed by the invention has the advantages of strong immunogenicity, good safety, no immune interference, high neutralizing antibody titer and long antibody duration.

The application discloses a preparation method and application of cystathionine-beta-synthase. The expression method of the cystathionine-beta-synthase based on a prokaryotic expression system is developed in the application, the soluble expression amount of the prepared cystathionine-beta-synthase is large, the cystathionine-beta-synthase is suitable for industrial production, the product has good stability, and the activity is high.

The present application mainly relates to a kind of preparation of sulfur-rich amino acid protein CMd-copper nanoclusters and its detection mercury ion method, comprising: a) by prokaryotic expression obtains CMd protein, and the protein concentration of 5 mg / mL-25 mg / mL CMd protein solution is obtained by purification.b) CMd is reacted with reducing agent TCEP after opening protein disulfide bond.c) the protein solution after reduction is reacted with anhydrous copper sulfate, and preparation high fluorescence CMd-copper nanocluster.d) CMd-copper nanocluster is applied to detect heavy metal mercury ion.The application method can be synthesized under mild aqueous conditions by "one-step method" structure controllable, stable CMd-copper nanocluster, widens the raw material of copper nanocluster synthesized with protein as template, avoids the use of organic solvent and strong reducing agent, and reduces the cost and environmental burden brought by noble metal raw material, and also has higher selectivity to mercury ion.

This invention belongs to the field of biomedical technology, specifically relating to a colorectal cancer antibody and its applications. The antibody is composed of a camel-derived VHH-3 single-domain antibody and a membrane-penetrating peptide TAT fused together via a flexible linker peptide (GGGGS)3, and its amino acid sequence is shown in SEQ ID NO:9. This invention uses phage display technology to screen for high-affinity VHH-3 (KD=0.9524 nM) and further constructs the membrane-penetrating nanobody TAT-VHH-3, achieving soluble and efficient preparation using a prokaryotic expression system. Experiments confirm that TAT-VHH-3 can significantly inhibit the proliferation (CCK-8 assay) and migration (scratch assay) of colorectal cancer Caco-2 cells in a concentration-dependent manner. The nanobody of this invention has advantages such as small molecular weight (approximately 16.1 kDa), strong penetrability, and high stability, providing a novel tool for tumor therapy targeting CaMKⅡα.

The application discloses a tandem antigen epitope peptide of G protein of Paralichthys olivaceus rhabdovirus and application thereof, and belongs to the field of fish molecular immunology. The amino acid sequence of the tandem antigen epitope peptide is shown as SEQ ID NO:1. The preparation method of the application comprises the following steps: (1) first, analyzing the structural characteristics of HIRRV-G protein and predicting B cell antigen epitopes, and synthesizing the antigen epitopes with advantages based on the prediction results; (2) then, screening candidate peptide segments with high affinity through enzyme-linked immunosorbent assay; (3) sequentially connecting the high-affinity peptide segment sequences meeting the requirements by using a GPGPG linker, and cloning the connected sequences into a pET-28a prokaryotic expression vector, so that the tandem antigen epitope peptide is obtained after induced expression. Compared with the full-length G protein, the tandem antigen epitope peptide has smaller molecular weight, stronger stability and stronger hydrophilicity; the tandem antigen epitope peptide can induce a large amount of specific antibodies in fish bodies, and significantly reduces the mortality of fish infected by the virus. The tandem antigen epitope peptide can be used for the development of HIRRV diagnostic reagents and subunit vaccines.

The invention relates to a lyase and a coding gene thereof, and application of the lyase in lysing bacteria. The bacteriophage capable of specifically cracking aeromonas hydrophila is obtained through separation and purification, lyase is cloned from a genome of the bacteriophage, and after prokaryotic expression and purification are carried out on the lyase, the obtained protein shows the characteristics of aeromonas hydrophila. The lyase disclosed by the invention has an obvious antibacterial effect on aeromonas hydrophila, so that the lyase has a potential application value in the aspect of controlling pollution of the aeromonas hydrophila.

The application discloses a preparation method of a recombinant ternary fusion protein dressing with epidermal cell activation function. The dressing is a fusion protein designed based on the research on the functions and properties of COL3A1 and IFN-kappa proteins by international peers and the laboratory. The specific method is that the fusion gene fragment of the covalent connection of COL3A1 and IFN-kappa with GGSGG as a linker is obtained by using overlap extension PCR technology, and a 6×His label is added. The target gene is cloned into a prokaryotic expression vector pET30 (modified in the laboratory) to obtain the fusion protein COL3A1-IFN-kappa with an MBP label. After expansion culture, the MBP-IFN-kappa-COL3A1 with a purity of more than 90% can be obtained through Ni-NTA column affinity chromatography. We verified the resistance of the fusion protein to salmonella in THP-1 cells, and verified the effect of the fusion protein on promoting wound healing and resisting salmonella infection on mice. Finally, it is proved that the MBP-IFN-kappa-COL3A1 has good uniformity, is easy to purify, has high activity, has no side effects, and is very suitable for being used as an epidermal cell activation dressing.

This invention discloses methanogenic lyases with the same protein family annotation as PeiR lyases and their applications. These enzymes are obtained through homology screening based on the known characteristics of PeiR lyases targeting peptide bonds in the methanogenic cell wall, using the Pfam protein family database annotation. PeiR lyase proteins participate in the biological process of hydrolyzing archaea cell walls, effectively killing methanogens and reducing methane production. Proteins homologous to this protein have potential methane-reducing potential. This invention integrates rumen microbial metagenomic sequencing data, uses a series of bioinformatics software to screen methanogenic viral proteins, and combines Pfam functional domain annotation for homology analysis, ultimately identifying a series of lyases. These lyases were successfully expressed in a prokaryotic expression system, and in vitro gas production experiments also showed that the crude enzyme solution significantly reduced methane production.

The invention belongs to the technical field of genetic engineering antibodies, and particularly relates to an antibody for non-competitive detection of aflatoxin B1 and application of the antibody. The antibody comprises a nano antibody of an anti-aflatoxin B1 antigen-antibody immune complex and a monoclonal antibody of the anti-aflatoxin B1; the amino acid sequence of the nano antibody of the anti-aflatoxin B1 antigen-antibody immune complex is as shown in SEQ ID NO. 1; the monoclonal antibody for resisting aflatoxin B1 comprises a heavy chain and a light chain; the amino acid of the heavy chain is as shown in SEQ ID NO.10, and the amino acid of the light chain is as shown in SEQ ID NO.11. The antibody for non-competitive detection of aflatoxin B1 provided by the invention is low in cost, can be prepared on a large scale through a prokaryotic expression system, is simple and convenient to prepare, has strong operability, and can be applied to non-competitive immunological analysis of aflatoxin B1.

The invention relates to a recombinant hirudin fusion protein, a coding gene and a prokaryotic expression method and application of the recombinant hirudin fusion protein. The recombinant hirudin fusion protein comprises an HMg variant amino acid sequence and a fusion tag. The recombinant hirudin fusion protein has the advantages that the hirudin variant in poecilobdella manillensis is adopted to construct an efficient prokaryotic expression system, the hirudin yield and activity are improved under the condition that post-translational modification is not needed, the anticoagulant efficiency and the production process of the recombinant hirudin fusion protein provide an important basis for development of a new generation of antithrombotic drugs, and the recombinant hirudin fusion protein has wide application prospects. The progress of cardiovascular disease treatment and hirudin production is expected to be promoted.

The invention discloses a bivalent subunit vaccine for preventing infection of haemophilus parasuis and porcine circovirus type 2. A core antigen combination of the vaccine comprises at least one antigen protein from haemophilus parasuis, and the antigen protein is selected from Ferrin, OppA and Hem-SAP and is combined with a porcine circovirus type 2 Cap protein. Wherein the NCBI (National Center of Biotechnology Information) login number of the Ferrin, the NCBI login number of the OppA and the NCBI login number of the Hem-SAP are WP160414389.1, ACL32731.1 and WP035493594.1 respectively. The antigen protein is subjected to codon optimization, is expressed and purified through a prokaryotic expression system, and is emulsified with ISA201 or a Freund's adjuvant to prepare the vaccine. Animal experiments prove that the vaccine can excite high-level antigen specificity IgG, cell factors IFN-gamma and white IL-4 in an immune animal body, namely, specific Th1 and Th2 type immune responses are generated. The vaccine can generate an immune protection rate of up to 80% when attacked by a serum type 5 haemophilus parasuis virulent strain, and generates an effective antibody response to the porcine circovirus type 2. The vaccine provided by the invention has the advantages of definite components, good safety and strong immune protection force.

The invention relates to the technical field of biological medicines, and discloses a construction method and expression application of an Hcp gene deleted strain of a rahnella aqua KCL-5 strain for fish. The Hcp 0186 gene deletion strain is constructed by using a homologous recombination method, the comparison between the deletion strain and a wild strain is carried out, and the result shows that the deletion of the Hcp 0186 gene has an influence on the growth speed, the pathogenicity of the Hcp 0186 gene to the zebra fish is obviously reduced, the survival rate of the infected zebra fish is increased from 0% to 52%, and the Hcp 0186 gene deletion strain can be used as a fish attenuated live vaccine. A recombinant prokaryotic expression vector pET32a-Hcp and expression and purification of fusion protein of the recombinant prokaryotic expression vector pET32a-Hcp are further constructed, and Hcp 0186 rabbit polyclonal antibody serum is prepared as a primary antibody and can be applied to localization expression analysis of fish tissues infected by the bacterium and detection of WB and IHC. Results prove that the Hcp 0186 gene deletion of the strain provides an attenuated strain vaccine and clinical diagnosis and detection application of infected fish of the attenuated strain vaccine, and a scientific basis can be provided for revealing a molecular pathogenic mechanism of the strain and development and application of a mutant strain of the strain.

The invention discloses a preparation method and application of carassius auratus rahn aquatic OmpA gene cloning and prokaryotic expression as well as a polyclonal antibody. The preparation method comprises the following steps: culture and DNA amplification of rahn aquatic, design of an OmpA primer, gene cloning and prokaryotic expression, back multi-point subcutaneous injection of an immune rabbit, heart blood sampling and preparation of the polyclonal antibody. The invention further provides OmpA protein prokaryotic expression and protein purification, preparation of OmpA polyclonal antiserum and application of fish bodies. According to the invention, a rahnella aquatilis OmpA gene is cloned, a specific Hind III and EcoR1 double-enzyme digestion primer sequence OmpA-1F / OmpA-1R is designed, a prokaryotic expression vector pET32a-OmpA is constructed, high-immunogenicity OmpA protein is obtained through purification, OmpA specific multi-antibody serum is prepared, and the OmpA specific multi-antibody serum can be used for preparing the multi-antibody serum. The OmpA polyclonal antibody can be used for detecting and positioning the expression application of rahnella aquatica OmpA protein in crucian carp bodies through bidirectional agar diffusion, an immunoblotting method and an immunohistochemical method, and provides a reference basis for research and development and application of rahnella aquatica subunit vaccines and a molecular diagnosis technology as well as immune prevention and control of infectious diseases of the rahnella aquatica subunit vaccines and the molecular diagnosis technology.

This invention discloses a methanogenic lyase homologous to PeiR lyase and its applications. The PeiR lyase protein, targeting the peptide bonds of the methanogenic cell wall, participates in the biological process of hydrolyzing the archaea cell wall, effectively killing methanogens and reducing methane production. Proteins homologous to this lyase possess potential methane-reducing potential. This invention utilizes a series of bioinformatics software to identify protein sequences encoded by methanogenic viruses from a large amount of rumen microbial virome sequencing data, and analyzes the structural homology between these proteins and PeiR. Ultimately, this invention successfully obtained a series of methanogenic lyases homologous to PeiR. To achieve the expression of these lyases, this invention designed multiple primers to synthesize the target sequences and successfully expressed them in a prokaryotic expression system. In vitro gas production experiments with the crude enzyme solution showed that these lyases are effective in reducing methane production.

This invention discloses a chikungunya virus genome fragment armored RNA reference, its preparation method, and its application. The preparation process involves the following steps: (1) constructing the prokaryotic expression backbone vector pACYCAR; (2) cloning the CKV genome fragment CKA (nt17-2276); (3) constructing the prokaryotic expression vector pACYCAR-CKA; (4) inducing the expression of armored RNA; and (5) purifying the armored RNA. This invention solves the technical problems of high biosafety risk, poor stability, and insufficient gene fragment coverage in existing CKV nucleic acid detection references. It fills the gap in the lack of high-quality references for CKV detection.

The invention discloses a synthesis method of ubiquitin (1-74) NHNH2, and belongs to the technical field of protein synthesis. The synthesis method comprises the following steps: utilizing a prokaryotic expression system, expressing a full-length protein of Ub (1-76) and a Josephin protein coded by Burkholderia pyrrocinia by virtue of an escherichia coli BL21 (DE3) strain, hydrolyzing the Ub (1-76) by virtue of the obtained 6His-BpJOS, cutting a peptide bond between Ub Arg-74 and Gly-75, and capturing a generated thiolipid intermediate by virtue of hydrazine hydrate, so as to obtain the Ub (1-74) NHNH2. According to the present invention, the ubiquitin cleavage enzyme BpJOS catalyzed in-situ activation process is adopted, such that the preparation yield is high, the operation is simple, the large-scale preparation can be achieved, the synthesis cost is low, and the method can be used for synthesizing the multi-ubiquitination modified fragment and synthesizing the Ub (1-74) probe as the precursor, and has wide application prospects.

The application provides a key enzyme involved in glycosylation modification of triterpene saponins, and an application thereof, and belongs to the technical field of genetic engineering. The glycosyltransferase gene is screened based on the omics research of the base plant of traditional Chinese medicine Duanxueliu, i.e. clinopodium gracile, and a pET28a-MBP-CcGT-g51295 prokaryotic expression vector is constructed to successfully obtain the glycosyltransferase. It is found that the glycosyltransferase can catalyze Saikogenin A and Saikogenin F to generate Prosaikogenin A and Prosaikogenin F respectively by using a glycosyl donor UDP-fucose; can catalyze Saikogenin A to generate clinopodiside I and clinopodiside X by using UDP-glucose; can catalyze Prosaikogenin A to generate Saikosaponin B1, Saikosaponin c1 and Saikosaponin X by using UDP-glucose; and can catalyze Prosaikogenin F to generate Saikosaponin A and Buddlejasaponin IV by using UDP-glucose, which reveals the catalytic function of the glycosyltransferase and provides a gene component for the biological research of triterpene saponins, and solves the problem of biological resources of rare saponins.

The invention discloses a recombinant prokaryotic expression vector, an expression strain, soluble human-derived protein and application, the recombinant prokaryotic expression vector comprises a first nucleotide sequence for coding a target human-derived protein and a second nucleotide sequence for coding a cold-adapted molecular chaperone, and a rare codon corresponding to host bacteria is introduced into the first nucleotide sequence to obtain a recombinant prokaryotic expression vector. The translation rate of a key site is actively reduced, a cold-adapted molecular chaperone is introduced into a second nucleic acid sequence, and correct folding and soluble expression of the human-derived protein in a prokaryotic host are promoted in a low-temperature induction manner, so that the high-yield and high-solubility human-derived soluble protein is obtained. The invention provides a feasible way for large-scale preparation of human soluble protein, and has important industrial application value.

The invention relates to a preparation method and application of an oligopeptide / polypeptide substitution antibody, and belongs to the technical field of antibody preparation. In order to solve the problems that an existing antibody preparation method is high in complexity, poor in stability and limited in platform applicability, the invention provides a preparation method of an oligopeptide / polypeptide substitution antibody, firstly, a random DNA sequence is synthesized and cloned to a two-hybrid system prey vector to construct a peptide library, an antigen protein is cloned to a two-hybrid system bait vector, and then the oligopeptide / polypeptide substitution antibody is obtained. Screening an antigen interaction peptide sequence through bait and prey library two-hybrid interaction, and performing prokaryotic expression purification or direct artificial synthesis on the antigen interaction peptide sequence to obtain a short peptide / polypeptide interacting with an antigen protein as an antibody substitute. According to the invention, ethical dispute and batch difference of animal immunity in traditional antibody preparation are avoided, period is shortened, cost is reduced, non-specific binding is less, sensitivity is greatly improved, plant endogenous non-tag protein can be specifically recognized, and the method is widely applicable to scenes of antibody substitution.

The application provides a fusion enzyme L-2FL-D for directionally catalyzing conversion of D-ortho-chlorophenylglycine into L-ortho-chlorophenylglycine, and a preparation method and application thereof, and belongs to the technical field of enzyme engineering. The application uses seamless cloning technology to perform homologous recombination on a linearized vector and an insertion fragment, so as to obtain a prokaryotic expression vector of the fusion enzyme L-2FL-D. The fusion enzyme L-2FL-D expression vector is expressed in a host cell, so as to obtain the fusion enzyme L-2FL-D. The application takes D-ortho-chlorophenylglycine and L-glutamic acid sodium salt as substrates, and under the action of coenzyme, the directionally catalyzing conversion effect of D-ortho-chlorophenylglycine into L-ortho-chlorophenylglycine is very remarkable, the substrate conversion rate reaches 98 %, and the application has extremely high application value in production of L-ortho-chlorophenylglycine.

The application discloses a nerve necrosis virus goliath grouper oral vaccine and a preparation method thereof. The amino acid sequence of the antigen of the nerve necrosis virus goliath grouper oral vaccine is shown as SEQ ID No: 1. The preparation method comprises the following steps: 1) construction of a recombinant plasmid: a fusion gene with a nucleotide sequence shown as SEQ ID No: 1 is synthesized, the fusion gene is inserted into an expression vector to obtain a recombinant vector, the recombinant vector is transformed into a prokaryotic expression bacterium, and the prokaryotic expression bacterium is cultured to select a successfully transformed prokaryotic expression bacterium; 2) the successfully transformed prokaryotic expression bacterium is induced to express; and 3) the induced prokaryotic expression bacterium is used to feed halocyprid larvae, and halocyprid larvae enriched and wrapped with the prokaryotic expression bacterium are obtained to obtain a nerve necrosis virus infection goliath grouper medicine. The nerve necrosis virus goliath grouper oral vaccine has high protection rate and an immune protection efficiency of 100% for goliath groupers. The application can be applied to the prevention and control of nerve necrosis virus diseases in the goliath grouper breeding process.

The present invention belongs to the technical field of genetic engineering, and specifically relates to a copepod luciferase mutant and the use thereof. The mutant is obtained by means of performing one or more mutations on a wild-type copepod luciferase with the signal peptide removed, and can be expressed in a prokaryotic expression system, resulting in an increased luminescence half-life or a signal rise within a certain time range, and the luminescence pattern of the luciferase is converted to glow-type luminescence or luminescence with a sustained increase in luminescence intensity. Some copepod luciferase mutants exhibit enhanced luminescence intensity. The mutant is widely used in biological research for real-time tracking and continuous monitoring, such as for labeling and tracking activities or processes in living organisms. On the basis of the advantage of increased luminescence half-life of the copepod luciferase mutant, the mutant can be used as and / or in the preparation of a glow-type luciferase. The copepod luciferase mutant is more suitable as a reporter gene for in-vivo detection in scientific research, and is conjugated with avidin, a digoxin antibody, etc., for sequencing, thereby shortening the sequencing time and improving the sequencing quality.

The invention belongs to the technical field of polypeptide preparation and biological medicine, and particularly relates to a preparation method of Jingzhaotoxin polypeptide IX (JZTX-IX) and application of Jingzhaotoxin polypeptide IX in treatment of diabetes mellitus. A chilobrachys jingzhao toxin polypeptide IX coding gene, a 6 * His tag nucleotide sequence, a thrombin restriction enzyme cutting site nucleotide sequence and an MBP hydrotropy tag nucleotide sequence are connected to a prokaryotic expression vector for prokaryotic expression, and the expressed polypeptide is purified to obtain the chilobrachys jingzhao toxin polypeptide IX protein. The target polypeptide with high purity, complete disulfide bond folding and uniform conformation is obtained, so that the high purity and biological activity of the target polypeptide are ensured. On the basis, the treatment activity of the JZTX-IX on diabetes mellitus especially type II diabetes mellitus is found and verified, and the JZTX-IX can remarkably reduce fasting blood glucose of mice with the type II diabetes mellitus, improve glucose tolerance and insulin sensitivity, relieve polydipsia and polyuria symptoms and promote insulin secretion and islet cell proliferation.