120 results about "Phage Display Techniques" patented technology

The invention belongs to the technical field of biotechnology, and relates to a tumor-targeted diagnosis nuclear magnetic resonance contrast agent and a preparation method thereof. The tumor-target diagnosis nuclear magnetic resonance contrast agent is prepared from a high molecular material, polyethylene glycol, a polypeptide, a dual-function ligand and gadolinium chloride by taking the polypeptide as a target head group, taking the tree-like high polymer material as a basic high molecular vector and connecting a small molecular contrast agent to the surface. In the invention, a polypeptide-modified high molecular material screened by using a phage display technology enters cells in an endocytic way, so that the introjection of the contrast agent by tumor cells is increased, and the characteristic of high safety is achieved. The target head group polypeptide used in the invention has the advantages of transferrin, can be used for effectively avoiding the interference of endogenous transferrin, has high targeting and diagnosing efficiencies, is simple to prepare, and can be further applied to target diagnosis of other tumor tissues.

The invention relates to four green fluorescent protein (GFP) nano antibody encoding genes as well as a preparation method and application thereof. The invention establishes a GFP nano antibody library. By using a phage display technique, four nano antibodies which are specifically combined with the GFP are screened from the antibody library, which are respectively named as A12, E6, D5 and B9. Nucleotide sequences of the four nano antibodies are obtained through sequencing, the nucleotide sequences are as shown in SEQ ID NO:1. SEQ ID NO:2, SEQ ID NO:3 and SEQ ID NO:4, and the nucleotide sequences have corresponding amino acid sequences as shown in SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8. A gene A12 is cloned to a transformed expression vector pADL-10b-His, and introduced intoan SS320 strain; genes E6, D5 and B9 are respectively cloned to transformed expression vectors pBAD 24-Flag-His, and are respectively introduced into a TOP10 strain, and then four prokaryotic expression vectors and strains of four nano antibodies are obtained. Four nano antibodies are expressed and purified, tests show that the four GFP nano antibodies can be specifically combined with GFP, and the genes can be applied to detection on GFP in basic research.

The invention belongs to the field of biotechnology, and specifically, relates to a tumor-targeting double-drug carrying and delivery system and a preparation method thereof. The tumor-targeting double-drug carrying and delivery system adopts high-molecular materials, polyethylene glycol, a polypeptide, a treatment gene and a chemotherapeutic drug, wherein the polypeptide is utilized as a targeting head and the high-molecular materials are utilized as base high-molecular carriers. The preparation method comprises that the chemotherapeutic drug of adriamycin and the like are inserted into double chains of the treatment gene to form a gene-chemotherapeutic drug compound; and through electrostatic interaction between the gene chemotherapeutic compound and the base high-molecular carriers, the tumor-targeting double-drug carrying and delivery system which simultaneously carries the treatment gene and the chemotherapeutic drug is obtained. The high-molecular materials are novel polypeptide-modified high-molecular materials, are selected by a phage display technology, and can enter into cells by endocytosis, and thus the gene and chemotherapeutic drug intake capability of tumor cells are improved and safety is improved. The polypeptide (T7) as the targeting head has advantages belonging to transferrin, can effectively avoid interferences from endogenous transferrin, has high targeting and treatment efficiency, is easy for preparation, and can be further developed and be utilized for targeting treatment on other tumor tissue.

The invention relates to the molecular immunology field. Although the existing foot-and-mouth disease weak poison vaccines and inactivated vaccines and other routine vaccines have good immunogenicity, but the vaccines have some unsafe factors such as reversion of virulence, incomplete virus blanching, the escape of live-virus from a preparation factory and the like so that people are motivated to find a more safe and effective FMD vaccine. In the molecular mimic peptide invention, phage display techniques are used to sieve effective FMDV epitopes to provide an O-type foot and mouth disease virus antigen epitope molecular mimic peptide and the invention also provides an application thereof in preparing immunogen and swine foot-and-mouth disease epitope peptide vaccine. The FMDV epitope peptide vaccine using the molecular mimic peptide of the invention has the antigenicity of target molecule without toxicity, is very safe and has low mass production cost and good economic effect and social effect.

The invention discloses an anti-human MSLN (mesothelin) monoclonal antibody, which is a specific high-affinity nano antibody developed by taking human MSLN as a target and based on a phage display technology. Compared with the prior art, the invention allows the anti-human MSLN monoclonal antibody to be successfully prepared, which is good in specificity, high in affinity and capable of binding tohuman MSLN expressed on the cell surface, and the anti-human MSLN monoclonal antibody is a potential drug for tumor immunotherapy.

The invention discloses a nanobody capable of resisting H9N2 subtype avian influenza viruses, a preparation method and an application. The amino acid sequence of the nanobody is as shown in SEQID NO:1. The nucleocapsid protein of the H9N2 subtype avian influenza viruses is expressed through a prokaryotic expression technique, then the nucleocapsid protein is used as an immunogen for immunizing Bactrian camels, a phage library is constructed, then a nanobody capable of resisting H9N2 nucleocapsid protein is obtained through screening by a phage display technique, then the nanobody and horse radish peroxidase (HRP) are subjected to fusion expression, and a fusion protein of the nanobody and the HRP is successfully prepared. When the fusion protein is applied to detection of antibodies capable of resisting H9N2 subtype avian influenza viruses (AIV) in chicken serum, the inventor finds that a detection method constructed through the fusion protein is high in sensitivity, and has the advantages that the operation is simple, secondary antibodies do not need to be used, and time consumed for detecting samples is short.

Disclosed is a new antibody which can be used to relieve addiction caused by nerve active substances, including opium, cocaine, benzedrine, ketamine, etc. Cocain and amphetamine-regulated transcript peptide antibody gene is selected through phage display technology; then single-chain antibody sequence of the cocain and amphetamine-regulated transcript peptide(CART) and the procaryon expression vector are connected and are induced to express and to be purified to obtain single-chain antibody in response to CART, which is named as CARTscFv(AH1,AH4B,AH6,AH19,AH33B,AH36). Injecteion of CARTscFv into the abdominal cavity of a mouse, together with the CART at the peripheral circulation system, leads to the reduction of the CART in the central nervous system of the mouse. Animal model with behavioral sensitization induced by cocain proves that the CART single-chain antibody can restrain the expression of the behavioral sensitization of the mouse induced by cacain, which shows that the CART single-chain antibody is of great potential in curing addiction and particularly relapse caused by nerve active.

The invention relates to a neutralizing single-domain antibody with a function of resisting novel coronavirus SARSCov2 and application of the neutralizing single-domain antibody. The antibody has at least one of a heavy chain CDR1, a heavy chain CDR2 and a heavy chain CDR3. The antibody can be used for preparing a diagnostic reagent or a diagnostic kit, an antibody medicine or a medicinal composition against COVID-19. An SARS-CoV-2 specific human monoclonal single-domain antibody is obtained by a phage display technology, has an SARS-CoV-2 pseudo-virus neutralizing effect, and has a synergistic neutralizing effect on D614G mutant strain pseudovirus when being combined with an IgG type SARS-CoV-2 neutralizing antibody 4A3 for use. Therefore, the antibody provides an efficient alternative antibody medicine for prevention and treatment of COVID-19.

The invention discloses an HPV16E7 protein nano-antibody as well as a preparation method and application thereof. According to the preparation method, camels are immunized by virtue of an HPV16E7 antigen expressed in a prokaryotic manner so as to obtain a high-quality immune nano-antibody gene pool; and an enzyme label plate is coated with HPV16E7 proteins, the immune nano-antibody gene pool is screened by virtue of a phage display technique to obtain nano-antibody genes with the HPV16E7 specificity, and then the nano-antibody genes are transferred to escherichia coli, so as to establish nano-antibody strains capable of realizing high-efficiency expression in the escherichia coli.

The invention relates to an antigenic epitope of spring viraemia of carp and belongs to the technical field of biology. According to the invention, by virtue of phage display technique, a positive clone is screened out by the use of spring viraemia of carp virus (SVCV) monoclonal antibody, a conserved sequence binding to the SVCV monoclonal antibody is found out, a clinical diagnosis reagent is prepared by the screened antigenic epitope, and spring viraemia of carp is prevented and treated by a small molecular antigen peptide as a vaccine. The gene sequence of the invention is SEQ ID NO:1. The phage display technique is utilized to screen the positive clone by SVCV monoclonal antibody and find out the conserved sequence which can bind to the monoclonal antibody with the ability of SVCV activity neutralization in a random peptide library. The site of the antigenic determinant is determined, and the relationship of its sequence, structure and function is analyzed. The study of inhibition effect to SVCV generated from the competitive binding of small peptide to SVCV receptor will have a huge application value for taking small molecular antigen peptide as vaccine in the future.

The invention discloses a goose-array type localized random mutation method and an application thereof in the monoclonal antibody molecular evolution technology. The goose-array type localized random mutation method provided by the invention comprises the following steps: designing a goose-array type primer of a target sequence of random mutation polymerase chain reaction (PCR) amplification, synthesizing the primer, mixing, and performing overlapping PCR to obtain the amplified sequence with random mutation in a designated area. The goose-array type localized random mutation method provided by the invention can be used in the monoclonal antibody molecular evolution. The invention further combines the key amino acid (KA) scanning, the goose-array type localized random mutation method and the phage display technology to provide a monoclonal antibody molecular evolution method. The mutation method provided by the invention is used in molecular evolution and has high speed, high success rate and wide application range.

The invention belongs to the technical field of biology and relates to polypeptide specifically combined with benzothiostrobin antibodies, including an application of the polypeptide to the detection of benzothiostrobin. According to the polypeptide, a phage display technique is adopted, and the benzothiostrobin antibodies which are purified by a protein A column are used for screening a phage display random octapeptide library for three rounds, so as to screen phage clones combined with the benzothiostrobin antibodies; a plurality of phage clones are selected at random for amplification and plasmid extraction, positive phage clones are selected by adopting a phage ELISA (enzyme-linked immuno sorbent assay) method, and the positive clones are sequenced, so as to obtain a polypeptide sequence. The invention further relates to the application of the phage display polypeptide to the detection of the benzothiostrobin. A phage enzyme-linked immunoassay method established by using the phage display polypeptide can be used for quickly, sensitively and conveniently detecting benzothiostrobin residues in the environment and agricultural products with low cost.

The invention discloses an anti-human MSLN monoclonal antibody and an application thereof, and is a specific and high-affinity single-chain antibody developed by taking human MSLN as a target based ona phage display technology. Compared with the prior art, the anti-human MSLN monoclonal antibody is successfully prepared, the antibody is good in specificity and high in affinity and can be combinedwith human MSLN expressed on the surface of a cell, and the anti-human MSLN monoclonal antibody is a potential drug for tumor treatment.

The invention relates to the field of blood purification, in particular to an anti-human IgE protein single-domain antibody and an application thereof. The structural general formula of the amino acidsequence of the single-domain antibody is shown as MDVQLQESGG-X1-LSC-X2-GRFTIS-X3-GQTQVTVVSS, wherein X1 is an amino acid sequence containing 1-9 amino acids, X2 is an amino acid sequence containing1-43 amino acids, and X3 is an amino acid sequence containing 1-38 amino acids. According to the invention, the soluble single-domain antibody capable of being expressed by prokaryotic or eukaryotic is screened by a phage display technology, and the production cost is low. An immunoadsorbent synthesized after the obtained single-domain antibody is coupled to a solid-phase carrier is high in humanIgE adsorption capacity and good in specificity; and the non-specific adsorption to human IgG is relatively low. The anti-human IgE protein single-domain antibody provided by the invention provides anew c selection for treating allergic diseases.

This invention relates to biotechnology field of cell and polypeptide. The aim of this invention is screening a small peptide that can strongly combine with MSC, and using it to separate and purify MSC and using it as carrying agent to prepare targeted therapeutic agent. The stated binding peptide sequence of MSC is ringed seven peptide sequence that abundantly contains Ser, Thr, Asn, Lys. Finally this invention uses phage display technique to screen small peptide that can strongly combine with MSC in random libraries of ringed seven peptides by affinity screening with MSC. MSC can link to solid phase sustentaculum through small peptide screened by using this invention. It can be used for screening, separating and purifying MSC. It can be used to prepare tracer agent of MSC after linking with fluorescent tumor marker. It can be used as carrying agent of MSC and medicine to prepare praeparatum about targeted therapy.

The present invention provides a recombinant humanized anti-hepatitis B surface antigen (HBsAg) Fab antibody as human hepatitis B surface antibody and its preparation method. The preparation method includes the following steps: utilizing phage display technique to obtain the gene of a humanized anti-HBsAg Fab fragment, making expression in prokaryotic expression system, on this basis utilizing PCK technique to amplifying the light-heavy chain gene of Fab, constructing it into the methyl alcohol yeast expression vector, using two-step process to convert yeast, constructing Fab engineering bacterium, secreting, expressing and producing Fab antbody fragment. The Fab antibody has strong HBsAG combination activity and antigen specificity, and the expression product of said gene has high application value in clinical therapy of hepatic disease.

Disclosed herein are methods for identifying, isolating and comparing proteins and other biomolecules differing between two complex biological samples using affinity chromatography and phage display techniques.

The invention discloses a brand-new PCSK9 antibody. The PCSK9 antibody is sieved through a phage display technology, then, through a gene engineering technology, a full-length gene sequence is obtained and applied to preparation of the antibody, and the prepared antibody is high in yield and short in period and is a humanized antibody. The invention further discloses an anti-tumor effect of the antihuman PCSK9 antibody. The way of thinking is expanded for research on occurrence and development of tumors in the future, and foundations are laid when the antihuman PCSK9 antibody is prepared intomonoclonal antibody medicine used for treating tumors in the later period.