69 results about "Phage Display Techniques" patented technology

The invention belongs to the technical field of biological medicine, and particularly relates to a nanometer antibody aiming at feline infectious peritonitis virus and application of the nanometer antibody. According to the invention, specific nano antibodies 2S-29 and 2S-39 of two novel FIPV S proteins are obtained by screening through a phage display technology, and a double-antibody sandwich ELISA method for detecting FIPV S antigens is provided. The two antibodies have excellent specificity and affinity to the feline infectious peritonitis virus FIPV S protein. A double-antibody sandwich ELISA method established based on the nano antibody has good specificity, repeatability and sensitivity, the lowest detection limit reaches 4 ng / mL, the FIPV S antigen can be rapidly and accurately detected, and a reliable means is provided for early diagnosis of feline infectious peritonitis.

The invention belongs to the technical field of immunodetection, and discloses a preparation and characterization method of a rabbit-derived single-chain antibody for detecting a liver cancer marker GPC3. The rabbit-derived single-chain antibody has the characteristics of small volume, high specificity, high stability and good sensitivity, and can be used in an immunoassay method for detecting a liver cancer marker GPC3; according to the method, a specific rabbit single-chain antibody is obtained through screening, expression and purification by using a phage display technology, a GPC3 antigen is coated on a solid-phase carrier, the rabbit single-chain antibody is used as a detection carrier, the binding force of the single-chain antibody and the antigen is identified, and the method is high in specificity, good in sensitivity and high in specificity. A novel single-chain antibody with high specificity and high sensitivity is provided for detection of GPC3 in serum.

This invention belongs to the field of microcystin-LR detection technology, providing anti-microcystin-LR nanobodies and their applications. The anti-microcystin-LR nanobodies have amino acid sequences as shown in SEQ ID NO.1, SEQ ID NO.2, or SEQ ID NO.3. This invention uses phage display technology to screen for nanobodies with high affinity and high specificity for recognizing microcystin-LR, exhibiting advantages such as strong stability and ease of large-scale expression. Various detection tools can be designed based on anti-microcystin-LR, including test strips, immunoassay kits, immunoaffinity columns, biosensor detection chips, or detection probes. This provides novel antibody resources for rapid monitoring of microcystin-LR and lays a material foundation for developing low-cost, high-performance immunoassay technologies, which is of great significance for promoting the monitoring and control of microcystin-LR pollution.

The invention discloses a human-derived hysteromyoma targeting peptide and application thereof, the sequence of the targeting peptide is selected from SEQ ID NO: 1 to SEQ ID NO: 5, and the SEQ ID NO: 1 (VN12) is the most preferable. The fusion protein is obtained by screening through a phage display technology, and has high hysteromyoma targeting specificity and low immunogenicity. The targeting peptide can be coupled with nuclide or fluorescent dye, and is used for accurate PET imaging, fluorescent diagnosis and intraoperative navigation of hysteromyoma. Experiments prove that the molecular marker is specifically enriched in tumor tissues (the tumor / muscle ratio is 60), the biological safety is good, the problems of insufficient diagnosis sensitivity and large treatment wound in the prior art are solved, and the molecular marker has a great application prospect in diagnosis and treatment of hysteromyoma.

The application belongs to the technical field of biological medicine, and discloses a cyclic peptide molecule specifically targeting CD5 and purposes thereof. The surface receptor CD5 of immune cells (T cells, B cells) has been proved to be a potential tumor treatment target, the present application uses the phage display technology widely applied to the development of polypeptide or antibody drugs to carry out multiple rounds of in vitro screening on human CD5 protein, and obtains a cyclic peptide molecule with drug potential and capable of specifically combining with CD5 through second-generation sequencing. The cyclic peptide molecule contains two cysteines, is modified into a ring through a specific chemical crosslinking agent, and the affinity of the cyclic peptide molecule to CD5 is determined to be in the low micromolar level through surface plasmon resonance technology, thereby laying a foundation for the development of a CD5-targeting inhibitor.

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 present invention discloses an intestinal microbiota Bacteroides fragilis toxin-neutralizing nanobody and its application. By deeply studying the enterotoxigenic Bacteroides fragilis and the toxin BFT secreted by it in the bodies of patients with colorectal cancer and breast cancer, nanobodies against BFT are expressed by phage display technology; nanobodies with high binding affinity to the antigen are screened out through biopanning technology; a nanobody with the ability to neutralize the toxicity of BFT, also known as Nb2.43, is obtained. The present invention expresses and optimizes to obtain a BFT nanobody protein with high affinity, stability and uniformity, opening up a new field for the treatment of colorectal cancer and breast cancer with nanobodies targeting BFT, and having good research value and application prospects.

The application relates to the field of antibody technology, in particular to an ACTH recombinant rabbit monoclonal antibody, a preparation method and application thereof. The ACTH recombinant rabbit monoclonal antibody is screened by using phage display technology. The monoclonal antibody has high specificity, high detection sensitivity and good affinity, and solves the problems of low content of adrenocorticotropic hormone in samples and great detection difficulty. Through identification, the monoclonal antibody has good stability and high accuracy when repeatedly detected.

The present invention discloses an EBV-related gastric cancer diagnostic marker and its application, wherein the diagnostic marker is selected from at least one of LF2 protein and BFRF3 protein. The present invention is the first to screen and obtain two diagnostic markers for EBV-related gastric cancer (EBVaGC) based on proteome chips and phage display technology - LF2 protein and BFRF3 protein, which can efficiently and accurately diagnose EBVaGC. In particular, the AUC of the combined diagnosis of these two proteins can reach 0.911, which is significantly better than the AUC of the individual diagnoses. And when diagnosing EBVaGC based on these two proteins, no tissue sample is required, only a serum sample is required, and it can be detected during a routine blood test. Therefore, compared with existing diagnostic methods, the present invention has the characteristics of high accuracy, small limitations, and low cost, reduces the cost of medical treatment for patients, is conducive to the realization of universal screening of the population, simplifies the diagnosis process of EBVaGC, and significantly improves the treatment efficiency.

A heavy-chain variable region sequence of the nanobody CPV-VHH-H1 has the amino acid sequence set forth in SEQ ID NO: 1; and a gene encoding the nanobody CPV-VHH-H1 has the nucleotide sequence set forth in SEQ ID NO: 2. A nanobody immune library of the CPV is constructed by a phage display technology, a specific anti-CPV nanobody CPV-VHH-H1 is obtained by screening, and it is verified by experiments that the nanobody may specifically bind to the CPV. A new nanobody preparation for use in clinical diagnosis and treatment of the CPV can be developed, and a certain theoretical reserve is provided for applying the nanobody to the field of veterinary biological products.

The application relates to the technical field of biological medicine, and provides an anti-GPC3 full humanization single-domain antibody and application thereof. The application uses phage display technology to obtain one anti-human GPC3 specificity full humanization monoclonal single-domain antibody through antibody screening by targeting human GPC3 protein. The obtained single-domain antibody can be specifically combined with human GPC3, and can effectively inhibit the nuclear translocation of YAP, provides an effective alternative antibody drug for GPC3-targeted HCC treatment, and has a potential clinical application prospect.

The application belongs to the field of biological medicine, and provides an antibody combined with a specific antigen peptide of common pemphigus and application thereof, and the application uses the principle of phage display technology to perform in-vitro affinity screening on a constructed library, combines phages with target antigen Dsg3, elutes non-specific binders, retains phages combined with the antigen closely, and then amplifies the phages and performs multiple rounds of affinity enrichment; multiple rounds of panning are performed, and after 3-5 rounds of screening, phage clones with strong Dsg3 binding capacity and high specificity can be obtained.

The invention belongs to the technical field of biological medicines, and particularly relates to an anti-CD22 nano antibody as well as a preparation method and application thereof. The anti-CD22 nano antibody comprises a framework region and a complementarity determining region, wherein the complementarity determining region comprises CDR1 (SEQ ID NO: 1), CDR2 (SEQ ID NO: 2) and CDR3 (SEQ ID NO: 3). The preparation method comprises the following steps: immunizing alpaca by using Human CD22 / His protein, extracting RNA (Ribonucleic Acid) from PBMC (Peripheral Blood Mononuclear Cell) and reversely transcribing into cDNA (Complementary Deoxyribose Nucleic Acid), constructing a phage display library, then performing CD22 antigen protein elutriation to obtain positive clone, and after sequencing analysis, expressing the antibody by using a mammalian cell expression system. The optimized phage display technology is adopted, the screening period is short, and the obtained nano antibody is small in molecular weight, stable in structure and high in affinity to CD22. The antibody can be efficiently expressed through mammalian cells, and natural modification activity is reserved.

This invention provides an anti-trimethoprim single-chain antibody for detecting trimethoprim-like drug residues, its preparation method, and its application. The amino acid sequences of the single-chain antibody are shown in SEQ ID3, SEQ ID4, and SEQ ID6. Compared with traditional monoclonal antibodies, the single-chain antibody has lower production costs, is simpler to prepare, and is easier to manipulate at the gene level. This invention utilizes trimethoprim-specific monoclonal hybridoma cells and employs phage display technology to screen for high-affinity single-chain antibodies. A single-chain antibody mutant with even higher affinity was successfully obtained through computer simulation combined with site-directed mutagenesis. Based on this mutant, an ic-ELISA was established for the detection of trimethoprim residues in animal-derived foods, meeting the needs of practical applications.

The present application relates to the field of biotechnology, in particular to a kind of hyaluronidase binding cyclic peptide, the cyclic peptide is obtained by screening phage display technology, its structure includes X 1(n) CX3X4X5X6X7X8X9X 10 CX 12(m) It has the efficacy of inhibiting hyaluronidase activity, higher transdermal absorption capacity and / or anti-inflammatory, can be used as hyaluronidase (especially PH20) inhibitor, applied in the fields of medicine, food and cosmetics.

The application discloses a single-chain antibody, the amino acid sequence of which is shown as SEQ ID NO:1, and the nucleotide sequence of which is shown as SEQ ID NO:2. The single-chain antibody against rabies virus is screened from an antibody library of immunized mice by using a phage display technology. Compared with a traditional cell fusion technology, the phage display technology is simple in operation, low in cost, short in time, and high in antibody discovery and screening efficiency. The single-chain antibody obtained by the application is low in molecular weight and immunogenicity, high in antibody specificity and affinity, and has the activity of neutralizing rabies virus, thereby providing a new idea for basic research of rabies virus and development of therapeutic drugs.

The invention belongs to the field of biological medicine, and provides an antibody combined with pemphigus vulgaris specific antigen peptide and application of the antibody. According to the principle of a phage display technology, a constructed library is subjected to in-vitro affinity screening, phages are combined with a target antigen Dsg3, non-specific binders are eluted, the phages tightly combined with the antigen are reserved, and the pemphigus vulgaris specific antigen peptide is obtained. Then, amplifying and carrying out affinity enrichment for multiple rounds; and carrying out multiple rounds of panning, and after 3-5 rounds of screening, obtaining phage clones with strong binding capacity with Dsg3 and high specificity.

The application belongs to the technical field of bioengineering, and relates to a fluorescent probe for detecting neuron-specific enolase and application. The application screens a specific binding short peptide E for neuron-specific enolase by using phage display technology, inserts a circular fluorescent protein R-GECO1 into the short peptide E, divides the E peptide chain into two parts E1 and E2, and forms a probe structure in the form of E1-R-GECO1-E2. The fluorescent probe protein provided by the application has relatively small molecular weight and is easy to mature, has large fluorescence dynamic change, has good specificity, and can detect neuron-specific enolase in and outside cells.

The invention discloses a CD147 nano antibody G45 as well as a preparation method and application thereof, and belongs to the technical field of molecular biology and immunology. A phage display technology is used for screening from a natural alpaca nano antibody phage library, finally three nano antibody genes are selected and cloned into pCold II, and prokaryotic expression recombinant plasmids are successfully constructed; the method comprises the following steps: carrying out inducible expression for 20 hours under the conditions that the final concentration of IPTG (isopropyl-beta-d-thiogalactoside) is 0.2 mmoL / L, the temperature is 16 DEG C and the speed is 100 rpm / min, carrying out nickel column purification, and then carrying out Coomassie brilliant blue dyeing and Western blot identification, so as to determine and obtain the CD147 nano antibody which is named as A8, B8 and G45; the binding activity of the three nano antibodies and the CD147 protein is detected through indirect ELISA (enzyme-linked immuno sorbent assay). The result shows that the CD147 antigen and the three nano antibodies have binding activity and are dose-dependent. Under the same conditions, when the incubation concentration of the nano-antibody is as low as about 0.625 g / mL, the G45 binding effect is good, the amino acid sequence of the nano-antibody is shown as SEQ ID NO.7, and the nucleotide sequence of the nano-antibody is shown as SEQ ID NO.10. The invention provides a more accurate method for high-sensitivity detection of CD147.

The present application belongs to the technical field of protein short peptide, and discloses a gastrin releasing peptide precursor specific binding short peptide and application. The gastrin releasing peptide precursor is a tumor marker with high specificity and sensitivity, and plays an important role in early diagnosis, curative effect monitoring and prognosis judgment of non-small cell lung cancer. The present application obtains a gastrin releasing peptide precursor short peptide P2 through phage display technology, and the amino acid sequence is shown as SEQ ID NO. 1. The specific short peptide screened by the present application has the characteristics of small relative molecular mass and high affinity, and thus a probe can be designed for detecting the gastrin releasing peptide precursor, thereby providing a new direction for early diagnosis of tumors and research and development of targeted drugs in clinic.

The present invention belongs to the field of biotechnology, and specifically relates to single-chain antibodies against pathogenic Leptospira, preparation methods and applications. Phage display technology is used to construct an immune library by immunizing rabbit spleens with Leptospira. After five rounds of solid-phase panning with decreasing antigen concentrations, ELISA identification and sequencing analysis, specific single-chain antibodies are screened. The host bacteria switching expression process is optimized to achieve efficient preparation of soluble single-chain antibodies. The antibodies have high sensitivity in sandwich ELISA detection and do not cross-react with common pathogens. In animal model treatment, the cocktail combination significantly improves the survival rate of infected golden hamsters and reduces the leptospira load in the kidneys, providing an innovative solution for the development of diagnostic reagents, antigen epitope identification and targeted treatment of leptospirosis.

The invention belongs to the technical field of nano-antibodies, and particularly relates to a nano-antibody for resisting H1N1 influenza virus NA protein as well as a preparation method and application of the nano-antibody. The method comprises the following steps: by taking A / Puerto Rick / 8 / 34 (H1N1) influenza virus as a research object, purifying and inactivating the influenza virus through sucrose density gradient centrifugation, immunizing alpaca by taking the influenza virus as an immunogen, and screening by utilizing a phage display technology to obtain a high-affinity spectral anti-avian influenza virus NA protein nano antibody. Animal experiments show that the nano antibody has a good prevention effect when acting on A / Puerto Radio / 8 / 34 (H1N1) influenza virus infected C57 mice. Through preparation of the anti-influenza virus NA protein nano antibody, not only is a material provided for development of an H1N1 influenza virus diagnostic reagent, but also a thought is provided for identification of H1N1 subtype influenza virus epitope and vaccine design.

The invention relates to the technical field of biology, and discloses a nano antibody targeting a porcine deltacoronavirus (RBD) and application of the nano antibody. Two high-specificity nano antibodies VHH1 and VHH2 for resisting the porcine deltacoronavirus S protein RBD are obtained by screening through a phage display technology and have good reaction activity and neutralizing activity, and a sandwich ELISA detection method based on the nano antibodies is established. The method is high in sensitivity, strong in specificity and good in repeatability, the lowest detection limit is 25 ng / mL, the PDCoV S protein RBD antigen can be rapidly and accurately detected, and the method is suitable for rapid detection and epidemiological monitoring of PDCoV. The invention provides a new technical means for prevention and control of the PDCoV.

The present application relates to the technical field of medicine, and specifically, a peptide capable of specifically binding to ovary-specific protein-inhibin alpha protein (INHA, alpha-inhibin) is obtained through phage display technology, the peptide is anchored on the surface of human umbilical cord mesenchymal stem cells through the method of click chemistry, and then a preparation of umbilical cord mesenchymal stem cells is prepared. The peptide in the preparation of umbilical cord mesenchymal stem cells of the present application serves as a bridge and is applied to the targeted treatment of ovary-related diseases by anchoring the ovary organ.

The present invention provides antibodies to TFF3 and OSM proteins, their combination, and their application in the diagnosis of colorectal cancer. By optimizing the immunogenic sequences of TFF3 and OSM, phage display technology is used to screen monoclonal antibodies with high affinity and high specificity. Directed mutagenesis and combinatorial library screening are then used to introduce mutations in the CDR regions of the antibodies to screen out the optimal TFF3 and OSM antibodies. This can effectively solve the problems of low affinity and specificity of existing antibodies, extend the detection range, and demonstrate extremely high collaborative diagnostic value in combined detection, significantly improving the diagnostic efficacy of colorectal cancer and having important clinical application value.

A mouse anti-GPC3 antibody scFv library is screened through a phage display technology, and a specific antibody capable of being combined with GPC3 and / or denatured GPC3 is obtained. The invention provides an anti-GPC3 antibody, nucleic acid for coding the antibody, a carrier containing the antibody, a host cell, a pharmaceutical composition or a kit, application of the antibody and the like. The antibody disclosed by the invention can be used for enzyme-linked immunosorbent assay, flow and immunohistochemical experiments, is higher in sensitivity and lower in immunohistochemical background staining, and has a wide application prospect in the field of medicines.

The application belongs to the technical field of biological medicine, and particularly relates to an anti-CD22 nanobody and a preparation method and application thereof. The anti-CD22 nanobody comprises a framework region and a complementarity determining region, wherein the complementarity determining region comprises CDR1 (SEQ ID NO: 1), CDR2 (SEQ ID NO: 2) and CDR3 (SEQ ID NO: 3). The preparation method comprises the following steps: immunizing a llama with a Human CD22 / His protein, extracting RNA from PBMC cells and reverse transcribing the RNA into cDNA, constructing a phage display library, obtaining a positive clone through CD22 antigen protein panning after sequencing analysis, and expressing the antibody through a mammalian cell expression system. The application adopts an optimized phage display technology, has a short screening cycle, and the obtained nanobody has a small molecular weight, a stable structure and high affinity to CD22. The antibody can be efficiently expressed through a mammalian cell, and retains natural modification activity.

The present invention relates to a goat antibody against mouse IgG1 and its application. The antibody comprises at least one of a heavy chain CDR1, a heavy chain CDR2, a heavy chain CDR3, a light chain CDR1, a light chain CDR2, and a light chain CDR3. The antibody can be used to prepare a secondary antibody against mouse IgG1. The present invention obtains a goat antibody targeting mouse IgG1 using phage display technology. The antibody can specifically recognize mouse IgG1 with high affinity, weakly binds to mouse IgG2a and IgG3, and has no cross-reactivity with human IgG, thus having important application value.

The present invention relates to the field of antibody technology, and specifically to a method for preparing and applying a recombinant monoclonal antibody against rT3. The present invention utilizes phage display technology to screen and obtain the rT3 recombinant rabbit monoclonal antibody of the present invention, wherein the heavy chain variable region thereof has the amino acid sequence shown in SEQ ID NO:1; and the light chain variable region thereof has the amino acid sequence shown in SEQ ID NO:2. The monoclonal antibody has strong specificity and high detection sensitivity, and solves the problem of low rT3 content in samples and high detection difficulty. It has been identified that repeated multiple detections using the monoclonal antibody have good stability and high accuracy. The antibody is used for the detection of rT3 content in serum, and combined with other thyroid index tests and clinical manifestations, it can diagnose hyperthyroidism and hypothyroidism, and is also clinically significant in the detection of diabetes, lung infection, myocardial infarction, cirrhosis, uremia, and some cancers.

The present invention relates to the field of pharmaceutical technology. Specifically, a short peptide capable of specifically binding to integrin αvβ5 is obtained by screening through phage display technology. This short peptide serves as a ligand for integrin αvβ5. Further, the short peptide is anchored on the surface of human umbilical cord mesenchymal stem cells by means of click chemistry, and then a preparation of umbilical cord mesenchymal stem cells is prepared for precise targeted treatment of ovarian diseases.