507 results about "Prokaryotic expression" patented technology

The invention belongs to the technical field of biological detection, and particularly relates to a monoclonal antibody 4F6 for HPV16 type E7 protein detection and application. The heavy chain variable region CDR sequences and the light chain variable region CDR sequences of the antibody are SEQ ID NO.1-3 and SEQ ID NO.4-6 respectively, and the antibody can be specifically combined with HPV16 type E7 protein without cross reaction. A double-antibody sandwich ELISA detection system constructed based on the antibody is combined with a biotin-avidin amplification technology, the sensitivity reaches 100 pg / mL, and the antibody is suitable for rapid detection of the HPV16 type E7 protein in a cervical exfoliated cell sample. The invention further provides the HPV16 type E7 recombinant protein which is obtained through prokaryotic expression and has immunocompetence, and the HPV16 type E7 recombinant protein is applied to antibody screening and detection. Compared with nucleic acid detection, the method has a lower false positive rate, can be used for early screening of cervical cancer and precancerous lesions, and has a good application prospect.

The present invention belongs to the field of biopharmaceutical technology, and specifically relates to a method for preparing GLP-1 or its analogs. The present invention provides a leader peptide, and a fusion protein comprising the leader peptide. The leader peptide or fusion protein is used to prepare a semaglutide precursor polypeptide, and the results show that the yield of the prokaryotic expression fusion protein can reach 26g / L, and the purity of the precursor polypeptide obtained after enzyme cleavage is higher than 95%. The precursor polypeptide is further side-chain modified and connected with a dipeptide to efficiently prepare semaglutide.

The invention discloses an oligopeptide composition for inhibiting inclusion body formation and promoting Gag-Like protein nanoparticle self-assembly, the oligopeptide composition comprises a C-terminal oligopeptide and an N-terminal oligopeptide, the amino acid sequence of the N-terminal oligopeptide is as shown in SEQ ID NO: 1, and the amino acid sequence of the C-terminal oligopeptide is as shown in SEQ ID NO: 2. The oligopeptide composition can effectively avoid formation of a prokaryotic expression protein inclusion body and / or promote dissolution of prokaryotic expression protein, the oligopeptide composition is further utilized to be combined with HIV-1p24 and human endogenous retrovirus K capsid protein CA, nanoparticles are prepared respectively, and the oligopeptide composition can be used as a carrier for antigen surface display or drug transportation. The nanoparticles formed by the HIV-1 capsid protein p24 and the human HERV K CA have cavities which are obviously larger than those of ferritin, so that the nanoparticles have higher loading capacity; as an antigen display platform, the antibody also has good stability and wide applicability.

The invention belongs to the technical field of biology, and particularly relates to a latex duplex immunochromatography test strip for rapidly identifying a porcine transmissible gastroenteritis virus (TGEV) and a porcine epidemic diarrhea virus (PEDV) and a preparation method of the latex duplex immunochromatography test strip. Soluble TGEV N protein and PEDV N protein with immunogenicity and reactivity are respectively obtained by utilizing a prokaryotic expression system, the soluble TGEV N protein and the soluble PEDV N protein are used as immunogenicity to immunize mice, and specific monoclonal antibodies of the TGEV N protein and the PEDV N protein are respectively obtained by utilizing cell fusion and subcloning screening technologies. The antibody variable region gene sequence is obtained by using a nested PCR amplification technology, and can be subsequently obtained by using a gene engineering or protein engineering method. Then, the latex duplex immunochromatography test strip for detecting TGEV and PEDV, which is convenient, rapid and high in sensitivity, and the preparation method are researched and developed on the basis of specific monoclonal antibodies of TGEV N protein and PEDV N protein.

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 relates to the technical field of biological medicines, in particular to a recombinant rabies virus nano-antibody fused with a solubilizing oligopeptide and a cell penetrating peptide and application of the recombinant rabies virus nano-antibody in preparation of rabies prevention and treatment products. The recombinant rabies virus nano-antibody fused with the solubilizing oligopeptide and the cell penetrating peptide comprises a humanized rabies virus nano-antibody, and the C end of the humanized rabies virus nano-antibody is fused with a solubilizing tag peptide P17 and the cell penetrating peptide. The recombinant rabies virus nano antibody utilizes a prokaryotic expression system, is low in cost, has excellent cell membrane and BBB penetrating ability, can enter a central nervous system from veins for virus neutralization treatment, and has an efficient passive immune effect.

The invention discloses methanogen lyase homologous with a PeiR lyase sequence and application of the methanogen lyase, and aims to solve the problem that PeiR lyase protein of a methanogen cell wall peptide bond can participate in a biological process of hydrolyzing archaea cell walls, effectively kill methanogen and reduce methane production, and protein homologous with the PeiR lyase protein has potential methane reduction potential. According to the invention, a series of biological information software is utilized to identify protein sequences coded by methanogens virus from rumen microbiome sequencing data, and sequence homology between the proteins and PeiR protein is further analyzed to obtain a series of methanogens lyases. In order to realize the expression of the lyase, multiple segments of primers are designed to synthesize a target sequence, and the target sequence is successfully expressed in a prokaryotic expression system. Through the detection of crude enzyme liquid, the effectiveness of the lyase in the aspect of reducing the methane yield is verified in an in-vitro gas production test.

The invention relates to the technical field of biology, and particularly discloses a fusion protein containing an SUMO tag and a preparation method and application thereof. The fusion protein provided by the invention comprises an SUMO tag and an antibacterial peptide, the antibacterial peptide can inhibit escherichia coli and staphylococcus aureus, and the amino acid sequence of the antibacterial peptide is as shown in SEQ ID No. 10, SEQ ID No. 6, SEQ ID No. 8, SEQ ID No. 12, SEQ ID No. 15 or SEQ ID No. 17. The fusion protein can be efficiently expressed through a prokaryotic expression system, renaturation of the antibacterial peptide can be successfully achieved after enzyme digestion and purification, the antibacterial activity of the antibacterial peptide is recovered, and therefore efficient preparation of the antibacterial peptide is achieved.

The invention discloses recombinant silk fibroin peptide as well as a preparation method and application thereof, and belongs to the technical field of cosmetic raw material development. The amino acid sequence of the recombinant silk fibroin peptide SFHR6 disclosed by the invention is as shown in SEQ ID NO. 1. Soluble expression of the recombinant silk fibroin peptide is achieved through prokaryotic expression and eukaryotic expression, the high-purity soluble recombinant silk fibroin peptide SFHR6 is obtained through nickel column affinity chromatography, hydrophobic chromatography, cation chromatography and anion chromatography technologies, and the recombinant silk fibroin peptide SFHR6 is high in purity, high in tyrosinase inhibition rate and strong in whitening effect. The purification process provided by the invention is simple and convenient, has good repeatability, effectively solves the quality control problem of naturally extracted protein products, has the advantages of high efficiency, high-purity heterologous expression and low large-scale production cost, and has relatively high industrial application potential.

The invention discloses prokaryotic expression and purification of Echinococcus multilocularis glutathione S-transferase, and preparation and application of a polyclonal antibody, and relates to the technical field of biology.The technical key point is that the preparation method of the polyclonal antibody of the Echinococcus multilocularis glutathione S-transferase comprises the following steps that S1, RNA in vesicle tissue of Echinococcus multilocularis is extracted, and cDNA is prepared; s2, carrying out PCR (Polymerase Chain Reaction) amplification by taking the cDNA as a template to obtain an EmGST gene which can encode an amino acid sequence as shown in SEQ ID NO: 1; s3, connecting the EmGST gene to a prokaryotic expression vector plasmid through a double digestion enzyme reaction to construct a recombinant vector, then transfecting the recombinant vector to competent escherichia coli, and inducing prokaryotic expression and purification to obtain a recombinant protein; and S4, immunizing a mouse to prepare antiserum by taking the echinococcosis multilocularis glutathione transferase as an antigen, and purifying the antiserum to obtain the polyclonal antibody of the echinococcosis multilocularis glutathione transferase. The ImGST protein polyclonal antibody prepared by the invention has the advantages of high titer and good specificity.

The invention discloses lnc.3024.2-GbMYB2 for regulating and controlling synthesis of gingko flavonoids and application of the lnc.3024.2-GbMYB2, and belongs to the technical field of genetic engineering, aiming at analyzing the biological functions of lncRNA (lnc.3024.2) and MYB target gene (Gb06719) participating in gingko flavonoids anabolism, by utilizing the technical means of bioinformatics analysis, real-time fluorescence quantification, subcellular localization, prokaryotic expression, genetic transformation and the like, the GbMYB2 can be used for regulating and controlling synthesis of the gingko flavonoids. The regulation mechanism of the transcription factor lnc.3024.2 and the target gene GbMYB2 of the lnc.3024.2 participating in the synthesis of the flavonoids in the ginkgo leaves is discussed. And a gene regulation network model of gingko flavonoid anabolism is further enriched. On the basis, the molecular mechanism of regulating and controlling the synthesis of the gingko flavonoids by the lncRNA targeting MYB is further analyzed on the early-stage basis, the content of the gingko flavonoids is increased by utilizing a genetic engineering technical means, and a new way is provided for researching the synthesis way of the gingko flavonoids.

The invention discloses a pertussis recombinant protein and a monoclonal antibody and application thereof.The pertussis recombinant protein is synthesized by selecting an S1 subunit of pertussis PT and a part of sequences of FHA protein, the pertussis recombinant protein is expressed through a prokaryotic expression system and purified, the protein serves as an antigen to immunize a mouse, and the pertussis recombinant protein is obtained. Positive hybridoma cell strains 3B10, 3D9 and 5F7 capable of stably secreting the antibody are obtained by adopting a hybridoma technology, the preservation numbers are respectively CCTCC NO: C202567, CCTCC NO: C202568 and CCTCC NO: C202569, and the obtained monoclonal antibody has relatively high affinity and detection sensitivity to pertussis PT and FHA recombinant proteins, is used for detecting a bordetella pertussis antigen, is strong in specificity and high in sensitivity, can be used for instant detection, and can be applied to clinical application. And the method has a relatively high application value.

The invention discloses methanogen lyase homologous with high-dimensional characteristics of PeiW lyase and application of the methanogen lyase, and aims to solve the problem that PeiW lyase protein of methanogen cell wall peptide bonds can participate in the biological process of hydrolyzing archaea cell walls, effectively kill methanogen and reduce methane production, and protein homologous with the protein has potential methane reduction potential. According to the method, a series of bioinformatics software is utilized, a protein sequence coded by methanogens virus is identified from a large amount of rumen microorganism virus group sequencing data, the high-dimensional homology of a deep learning model between the protein sequence and PeiW is analyzed, and two methanogens lyases similar to the high-dimensional characteristics obtained by the PeiW model are obtained. In order to realize the expression of the lyase, multiple segments of primers are designed to synthesize a target sequence, and the target sequence is successfully expressed in a prokaryotic expression system. Through detection of a crude enzyme solution, the effectiveness of the lyase in the aspect of reducing the yield of methane is verified in an in-vitro gas production test.

The invention discloses a herbicide-resistant protein GAT hybridoma cell strain, an antibody generated by the herbicide-resistant protein GAT hybridoma cell strain and an application of the herbicide-resistant protein GAT hybridoma cell strain. The herbicide-resistant protein GAT hybridoma cell strain is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.46333. The preparation method comprises the following steps: a) purifying prokaryotic expression to obtain GAT recombinant protein; b) immunizing animals: immunizing BALB / c mice by taking the GAT recombinant protein as an antigen; c) cell fusion: splenocytes of the immune BALB / c mice are collected and fused with SP2 / 0 cells; and d) cell strain establishment: carrying out subcloning through a limited dilution method, carrying out ELISA detection after 5-7 days of subcloning until a hybridoma cell strain capable of stably secreting a positive antibody is screened out, and carrying out amplification, re-culture and storage. The monoclonal antibody secreted by the hybridoma cell strain lays a foundation for detection of herbicide-resistant protein GAT in transgenic crops, so that development, seed production and seed conservation of transgenic gat crops are supported, and stable industrial promotion of the transgenic gat crops and sustainable application of related transformants are guaranteed.

The invention discloses methanogen lyase with the same protein family annotation as PeiR lyase and application of the methanogen lyase, and the methanogen lyase is obtained through homologous screening of Pfam protein family database annotation based on known PeiR lyase characteristics aiming at methanogen cell wall peptide bonds. The PeiR lyase protein can participate in the biological process of hydrolyzing archaea cell walls, methanogens are effectively killed, methane production is reduced, and the protein homologous with the protein has potential methane reduction potential. According to the invention, by integrating metagenome sequencing data of rumen microorganisms, screening methanogenic bacterium virus protein by using series bioinformatics software, and combining Pfam functional domain annotation to carry out homologous relationship analysis, a series of lyase is finally identified and is successfully expressed in a prokaryotic expression system, and meanwhile, an in-vitro gas production experiment result also shows that the methanogenic bacterium virus protein can be successfully expressed in a prokaryotic expression system. The crude enzyme liquid can significantly reduce the methane generation amount.

The invention discloses methanogen lyase homologous with high-dimensional characteristics of PeiR lyase and application of the methanogen lyase and aims to solve the problems that PeiR lyase protein of methanogen cell wall peptide bonds can participate in the biological process of hydrolyzing archaea cell walls, methanogen is effectively killed, methane production is reduced, and protein homologous with the protein has potential methane reduction potential. According to the invention, a series of biological information software is utilized to identify protein sequences coded by methanogen viruses from a large amount of rumen microbiome sequencing data, and high-dimensional homology between the proteins and PeiR proteins based on a deep learning model TM-Vec is further analyzed, so that a series of methanogen lyases are obtained. In order to realize the expression of the lyase, multiple segments of primers are designed to synthesize a target sequence, and the target sequence is successfully expressed in a prokaryotic expression system. Through the detection of crude enzyme liquid, the effectiveness of the lyase in the aspect of reducing the methane yield is verified in an in-vitro gas production test.

The invention relates to a porcine reproductive and respiratory syndrome virus (PRRSV) dimer nucleocapsid (N) protein (PRRSV N-dimer) and application thereof. The PRRSV N-dimer is formed by connecting N protein amino acid sequences in series through (GGGGS) 3linker. According to the invention, a GGGGS 3linker nucleotide sequence is connected in series with a PRRSV NADC30-like strain N protein gene sequence to construct a prokaryotic expression vector, and a recombinant PRRSV N-dimer is expressed in escherichia coli. Through SDS-PAGE (Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis) and Western-blot detection, the recombinant PRRSV N-dimer obtains soluble expression and can be subjected to a specific reaction with PRRSV positive serum; through detection by a freeze thawing method and an ELISA (Enzyme-Linked Immunosorbent Assay) method, compared with a PRRSV monomer N protein (PRRSV N-monomer), the PRRSV N-dimer protein can be stably preserved, and the immunoreactivity is better. A PRRSV antibody indirect enzyme-linked immunosorbent assay (iELISA) detection method is established on the basis of a PRRSV N-dimer, and can be applied to diagnosis and monitoring of PRRSV infection.

The invention relates to the technical field of biology, in particular to a preparation method and application of a recombinant human long-acting interleukin-22 binding protein. The amino acid sequence of the recombinant human long-acting interleukin-22 binding protein is as shown in SEQ ID No. 1. According to the method for preparing the IL-22BP recombinant protein with high biological activity by utilizing an Escherichia coli prokaryotic expression system, a novel fusion protein is designed, a sequence for coding human IL-22BP is connected with a sequence for coding ABD to construct an IL-22BP-ABD fusion gene, the IL-22BP-ABD fusion gene is induced to be expressed in Escherichia coli, inclusion body protein is separated, and the IL-22BP recombinant protein with high biological activity is obtained. The target protein is obtained through denaturation, purification and renaturation, and the biological activity of the IL-22BP-ABD is verified through in-vivo and in-vitro experiments.

The invention relates to the technical field of molecular biology and protein engineering, in particular to a lactic acid bacteria antibacterial peptide LABA4 multi-copy expression method and application. The invention aims to provide a prokaryotic expression method of an antibacterial peptide LAB4 tandem gene based on a self-assembled peptide and application, so that the problems of toxicity to a host, low expression quantity and non-ideal product activity in a large intestine expression system are solved, the antibacterial peptide is efficiently expressed in escherichia coli, and the antibacterial activity is effectively improved. Particularly, the characteristics of specific cutting and no amino acid residue of enterokinase are utilized, modified recombinant enterokinase is added between LAB4 monomers to serve as an interval restriction enzyme cutting site, a gene shuffling technology is utilized to design and construct three-six copy tandem recombinant plasmids of LAB4, the self-cleavage characteristic of intein is utilized, and the recombinant enterokinase recombinant plasmids of LAB4 can be used for preparing the recombinant enterokinase recombinant plasmids of LAB4, so that the recombinant enterokinase recombinant plasmids of LAB4 can be used for preparing the recombinant enterokinase recombinant plasmids of LAB4. An optimized cspA cold shock promoter in a pCold I vector is adopted, and high-efficiency expression of tandem LAB4 in an escherichia coli expression system is realized through 15 DEG C low-temperature induction precise regulation and control.

The invention discloses an influenza C virus HEF protein polyclonal antibody preparation method, which comprises: carrying out signal peptide prediction, antigen epitope screening and hydrophobicity analysis through bioinformatics, constructing a recombinant prokaryotic expression vector pET32a-HEF by using a seamless cloning technology, and efficiently expressing the HEF protein in Escherichia coli to obtain the influenza C virus HEF protein polyclonal antibody. The inclusion body protein yield is improved by optimizing conditions; and purifying by nickel column affinity chromatography to obtain high-purity recombinant protein, emulsifying the high-purity recombinant protein and a Freund's adjuvant, immunizing a Japanese white rabbit, immunizing for three times, and collecting high-titer serum. The method breaks through detection limitation caused by antigen tag concealment in a eukaryotic expression system, the obtained polyclonal antibody is high in specificity, the eukaryotic expression HEF protein can be accurately recognized, and a key tool is provided for ICV virus-like particle identification, vaccine research and development and diagnosis technologies. Compared with a traditional method, the scheme is simple and convenient to operate, low in cost and high in antibody titer, and has remarkable application value.

The invention discloses cloning and functional identification of a liverwort flavone synthetase gene, and belongs to the technical field of gene engineering. According to the invention, one flavone synthase I (flavones synthase I, FNS I) is obtained through screening, and is named as MpFNS I; a prokaryotic expression system is utilized, an MpFNS I recombinant protein is obtained through purification, and the result of in-vitro enzyme activity identification shows that an MpFNS I enzyme substrate is relatively wide in selectivity, has a flavone synthetase function and also has a part of flavonol synthetase function. The liverwort flavonoid has a significant difference on affinity and catalytic efficiency of different substrates, the in-vivo function of the liverwort flavonoid is verified by utilizing heterologous expression of arabidopsis thaliana, experimental evidence is provided for comprehensively analyzing a biosynthetic pathway of the liverwort flavonoid, and meanwhile, a research target is provided for deeply researching a mechanism for synthesizing and responding to UV-B radiation of the liverwort flavonoid.

The invention discloses a method for realizing high-efficiency selenium labeling of protein, which comprises the following steps of: in the process of expressing plasmids containing target protein through a prokaryote expression system, realizing high-efficiency replacement of cysteine sulfur atoms in the target protein by selenium atoms by regulating and controlling the ratio of selenium to sulfur elements in a culture medium; on the premise of keeping a good growth state of cells, the selenium labeling efficiency can reach 86%, and the protein expression quantity is stabilized at about 1mg / g (protein / thallus wet weight); structural analysis shows that the secondary structure of the obtained selenium-labeled protein is basically consistent with that of natural protein and is not obviously changed. The method is easy and convenient to operate, high in labeling efficiency, high in protein yield, good in repeatability and suitable for structural biology research such as nuclear magnetic resonance, an effective means is provided for research of the functional mechanism of sulfur atoms in biomacromolecules (including small peptides, polypeptides, peptide fragments, proteins and protein or peptide complexes) with selenium as a probe, and the method has a wide application prospect. Good scientific research application prospects and industrial popularization values are realized.

The invention relates to the technical field of immunodetection, and discloses a bovine nodular skin disease virus chimeric antigen and application thereof in an ELISA (enzyme-linked immuno sorbent assay) detection kit. According to the chimeric antigen, a gene of a dominant region of a bovine nodular skin disease virus antigen is selected to design a chimeric antigen gene, meanwhile, sequence optimization is performed, a chemical synthesis method is used for synthesizing a coding gene of the chimeric antigen of the bovine nodular skin disease virus, and then the chimeric antigen is obtained in a prokaryotic expression mode. An ELISA antibody detection kit developed on the basis of the chimeric antigen has extremely high sensitivity and specificity, can rapidly and specifically detect bovine nodular skin disease virus antibodies in serum, is suitable for monitoring and checking the nodular skin diseases of cattle in large-scale breeding, and has relatively high practical value.

The invention belongs to the technical field of plant disease control, and particularly relates to preparation and application of diaphorina citri sourced antibacterial peptide DcAMP1. The amino acid sequence of the antibacterial peptide DcAMP1 is SEQ ID NO. 1, and the nucleotide sequence of the gene for coding the antibacterial peptide DcAMP1 is SEQ ID NO. 2. The prokaryotic expression plasmid is adopted to construct the recombinant plasmid containing the gene encoding the antibacterial peptide DcAMP1, prokaryotic expression of the antibacterial peptide DcAMP1 is achieved, and the method is simple and easy to implement. After being purified, the antibacterial peptide DcAMP1 obtained through prokaryotic expression has an obvious antibacterial effect on a liberobacter asiaticum related bacterium sinorhizobium fredii, and the titer of the liberobacter asiaticum in a sweet orange tree with the liberobacter asiaticum can be obviously reduced.

The invention discloses a polyclonal antibody of a grouper iridovirus SGIV VP101 gene and application of the polyclonal antibody. The polyclonal antibody is prepared from an SGIVVP101 gene, and the nucleotide sequence of the VP101 gene of an optimized codon is as shown in SEQ ID NO. 1. The polyclonal antibody of the SGIV VP101 gene recombinant expression protein prepared by the invention has good specificity, not only can specifically recognize a prokaryotic expression product of the SGIV VP101, but also can be used for quantitative and positioning analysis of the SGIV VP101 in vivo and in vitro. The successful preparation of the polyclonal antibody of the recombinant expression protein of the SGIV VP101 gene lays a foundation for the establishment of an SGIV immunological detection method, the quantitative and positioning analysis of the protein of the VP101 gene and the analysis of gene functions.

The invention belongs to the technical field of genetic engineering, and particularly relates to a mutant P17 oligopeptide and application thereof in preparation of a nano antibody. The amino acid sequence of the mutant P17 oligopeptide is KGFRDEKKRFKNTKG. The mutant P17 oligopeptide is a mutant P17 oligopeptide. The mutant P17 oligopeptide provided by the invention has good chaperone-like activity and dissolution promoting effect, has good applicability to different nano antibody strains, is fused with a nano antibody and is expressed in a prokaryotic expression system, so that the solubility and expression efficiency of the nano antibody in the prokaryotic expression system can be effectively improved, and the application prospect is broad. The soluble yield of the nano antibody is greatly improved; moreover, the mutant P17 oligopeptide is beneficial to keeping the biological activity of the antibody, the nano antibody with high activity and high expression quantity is obtained, favorable conditions are created for large-scale production of the nano antibody, and the mutant P17 oligopeptide has a wide application prospect.

The invention discloses an application of an AP2-F2 protein polyclonal antibody as a cryptosporidium female gamete positioning tag antibody. The AP2-F2 protein of cryptosporidium parvum is subjected to truncated prokaryotic expression, protein is purified to immunize an ICR mouse, a polyclonal antibody is prepared, ELISA and WB detection of antibody titer are carried out to prove that the polyclonal antibody is effective, then indirect immunofluorescence detection of the antibody is carried out to determine that the polyclonal antibody is located on the female gametes of cryptosporidium parvum, and the polyclonal antibody can be used as a label to locate the female gametes of cryptosporidium parvum. The method plays an important role in localization research of unknown protein of cryptosporidium.

The invention belongs to the technical field of plant disease control, and particularly relates to preparation and application of diaphorina citri sourced antibacterial peptide DcAMP2. The amino acid sequence of the antibacterial peptide DcAMP2 is SEQ ID NO. 1, and the nucleotide sequence of the gene for coding the antibacterial peptide DcAMP2 is SEQ ID NO. 2. The prokaryotic expression plasmid is adopted to construct the recombinant plasmid containing the gene encoding the antibacterial peptide DcAMP2, prokaryotic expression of the antibacterial peptide DcAMP2 is achieved, and the method is simple and easy to implement. After being purified, the antibacterial peptide DcAMP2 obtained through prokaryotic expression has an obvious antibacterial effect on a liberobacter asiaticum related bacterium sinorhizobium fredii, and the titer of the liberobacter asiaticum in a sweet orange tree with the liberobacter asiaticum can be obviously reduced.

The invention discloses a human growth hormone detection antibody and a preparation method thereof. The amino acid sequence of the detection antibody is one of SEQ ID NO. 1 and SEQ ID NO. 2; the preparation method comprises the following steps: extracting RNA (Ribonucleic Acid), performing reverse transcription, amplifying obtained cDN A, inserting into escherichia coli, and constructing a human growth hormone primary library; the M13KO7 auxiliary bacteriophage invades the human growth hormone primary library to construct a bacteriophage primary library; carrying out three rounds of solid phase panning on the phage primary library, and carrying out monoclonal screening, ELISA detection and sequencing to obtain a target gene sequence; and synthesizing the target gene sequence into a prokaryotic expression plasmid, introducing the prokaryotic expression plasmid into escherichia coli, and adding IPTG for expression to obtain the detection antibody. The detection antibody has the characteristics of low economy, strong stability and simple subsequent operation, and solves the problem that animal immunization is always needed to prepare the antibody in the subsequent process in human growth hormone detection.