100 results about "Antibody affinity" patented technology

The present invention provides methods for producing mutationally-altered immunoglobulins and compositions containing such mutationally-altered immunoglobulins, wherein the mutationally-altered immunoglobulins have at least one mutation that alters the pattern of glycosylation in a variable region and thereby modifies the affinity of the immunoglobulin for a preselected antigen. The methods and compositions of the invention provide immunoglobulins that possess increased affinity for antigen. Such glycosylation-altered immunoglobulins are suitable for diagnostic and therapeutic applications.

The invention relates to gene engineering and antibody preparation and specifically discloses a preparation method and application of a high-throughput fully-humanized antibody. The preparation methodcomprises the following steps: separating peripheral blood monouclear cells; separating single cells of plasma cells or antigen-specificity memory B blymphocytes; amplifying the heavy-chain and light-chain gene variable regions of single B cell antibody by use of a primer provided by the inventor; establishing an expression system containing antibody heavy-chain and light-chain genes by use of alinear expression system containing a heavy-chain fragment or light-chain fragment constant area; finally, separating and purifying a fully humanized monoclonal antibody. By adopting the primer combination provided by the invention to amplify the genes in the antibody heavy-chain and light-chain variable areas, natural pairing of the light-chain and heavy-chain variable areas can be maintained, and the preparation method has the advantages of high gene diversity, high titer, full humanization, high antibody affinity, strong specificity, no heterologous serum reaction, no risk of propagating other infectious diseases, etc.

The invention discloses a nanobody of the anti-GPC 3 (Glypican 3) protein and a preparation method and application of the nanobody. A prokaryotic expression GPC 3 fusion protein is used to immunize acamel, the RNA in a spleen tissue of the camel is extracted and is used as a template to implement inverse transcription to form cDNA, the cDNA is constructed to a carrier of an outer capsid protein of a bacteriophage to construct a bacteriophage display library, and the storage capacity and the titer are calculated. Then the nanobody specifically combined with the GPC 3 is screened from the library according to the antigen-antibody affinity principle after elutriating for three times, a gene of the specific antibody is then obtained, an expression carrier is constructed, the prokaryotic expression is implemented, the expression carrier is purified and identified, and the required nanobody is obtained.

The invention discloses an antibody humanization transformation method. The antibody humanization transformation method comprises the following steps: analyzing an antibody gene sequence; starting antibody Fab isogeny modeling and optimization; ascertaining humanization mutation locus by epitope scanning, simulating virtual mutation molecular dynamics, and confirming key amino acid; the antibody humanization transformation method designs reasonable humanization antibody through the analysis, and further uses the epitope to scan and authenticate antibody humanization degree; and finally authenticates the appetency of the humanization antibody in a biological experiment. The antibody humanization transformation method has the advantages that the antibody humanization transformation method can be used for humanization transformation of mouse sources or source antibodies of other animals, only needs to provide the gene sequence of the antibody Fab, and is not dependent on information of antigen epitope. The humanization antibody designed by the antibody humanization transformation method has higher appetency maintenance, higher humanization degree, is capable of solving a contradiction between antibody appetency and humanization degree to a maximum degree.

The invention relates to the technical field of biology and particularly discloses a human anti-CD20 monoclonal antibody and a preparation method and application thereof. In the preparation method, a large-capacity natural human phage antibody library is constructed and the antibody library is screened to obtain a human anti-CD20 antibody 3C5, wherein the amino acid sequence of the heavy chain variable region is shown in SEQ ID NO:6 and the amino acid sequence of the light chain variable region is shown in SEQ ID NO:8. In addition, the invention also discloses a preparation method of the antibody 3C5, a nucleotide sequence coding the antibody 3C5 and an expression vector and host cell containing the nucleotide sequence. Compared with the other anti-CD20 antibodies, the human monoclonal antibody 3C5 has higher antibody affinity and ADCC and CDC activities; and the antibody 3C5 can be used to prepare anticancer medicaments.

Compositions, methods, and kits are provided for efficiently generating and screening humanized antibody with high affinity against a specific antigen. The library of humanized antibody is generated by mutagenizing a chimeric antibody template that combines human antibody framework and antigen binding sites of a non-human antibody. Alternatively, the library of humanized antibody is generated by grafting essential antigen-recognition segment(s) such as CDRs of the non-human antibody into the corresponding position(s) of each member of a human antibody library. This library of humanized antibody is then screened for high affinity binding toward a specific antigen in vivo in organism such as yeast or in vitro using techniques such as ribosome display or mRNA display. The overall process can be efficiently performed in a high throughput and automated manner, thus mimicking the natural process of antibody affinity maturation.

The invention discloses an artificial immunization non-supervision image classification method based on manifold distance and relates to the technical field of image processing. The specific process includes: (1) inputting an image to be classified and setting an initialization parameter to generate initialized antibody population; (2) based on the manifold distance, classifying the category of the sample point of the image to be classified and calculating the affinity of the antibody population; (3) carrying out clonal proliferation operation on the antibody population; (4) carrying out clonal variation operation on the antibody population after clonal proliferation; (5) classifying the category of the image to be classified according to a code of the antibody population after clonal variation and calculating the affinity of the antibody population; (6) carrying out clonal selection operation on the antibody population according to the antibody affinity; and (7) according to set maximum iterations, judging the stop condition of the category classification result of the image to be classified and determining the final classification result. The classification method has the advantages of low sensitivity of image data structure, non-supervision execution, good classification effect and strong robustness, and can be applied to the target identification in the field of image processing.

An electro-hydrodynamic apparatus and method of using the same is disclosed. The electro-hydrodynamic apparatus includes a liquid sample supported on a substrate, with at least one electrode located proximate the surface of the liquid sample without contacting the liquid sample. A power supply creates an electric field proximate the surface of the liquid sample, thereby inducing a motion to the liquid sample. The apparatus may be used for focusing and separating particles within a liquid, and pumping and mixing a liquid sample or a liquid mixture with or without particles. The apparatus creates a primary rotational flow on a liquid surface to create a secondary inertial flow. The apparatus may be used to focus particles and / or pathogens to increase the sensitivity of current detection techniques and to enhance immuno-sensing techniques, as well as to mix heterogeneous components of a liquid sample by acting as a stirring without mechanical moving parts and to enhance antibody-antigen interactions, to pump liquids in lab-on-a-chip, clinical and environmental diagnostic kits, or to separate particles and / or pathogens by utilizing different dielectrophoretic mobilities, magnetic susceptibilities and / or antibody affinities.

Compositions, methods, and kits are provided for efficiently generating and screening humanized antibody with high affinity against a specific antigen. The library of humanized antibody is generated by mutagenizing a chimeric antibody template that combines human antibody framework and antigen binding sites of a non-human antibody. Alternatively, the library of humanized antibody is generated by grafting essential antigen-recognition segment(s) such as CDRs of the non-human antibody into the corresponding position(s) of each member of a human antibody library. This library of humanized antibody is then screened for high affinity binding toward a specific antigen in vivo in organism such as yeast or in vitro using techniques such as ribosome display or mRNA display. The overall process can be efficiently performed in a high throughput and automated manner, thus mimicking the natural process of antibody affinity maturation.

The invention belongs to the technical field of biology, and particularly discloses a method for quantitatively detecting a protein acetylation level. The method particularly comprises the steps of preparing protein chips, drawing standard curves and detecting actual samples. The method overcomes the defects that antibodies have weak affinities and acetylated protein is difficult to enrich efficiently when acetylation antibodies are subjected to immune precipitation enriching directly; the protein acetylation level can be quantitatively detected quickly and simply; the used sample amount is less; the difference comparison among the different samples is facilitated; the study of an acetylation difference spectrogram provides a technology platform for establishing high-flux protein acetylation difference spectral analysis; and a predictive value of an acetylation state for liver cancer metastasis can be investigated.

The invention discloses an IgG antibody affinity peptide-alkaline phosphatase fusion protein which is a fusion protein formed by an IgG antibody affinity peptide and alkaline phosphatase, can be used for immunoassay as a substitute enzyme-labelled antibody. The fusion protein has the binding activity with an IgG antibody and the AP (Alkaline Phosphatase) catalytic activity once generated, the label ratio of the binding activity and the AP catalytic activity is 1:1, the enzyme specific activity of the fusion protein is 386 plus / minus 82U / mg, and an affinity constant Ka with a rabbit IgG antibody is congruent to 6.7*107L.mol-1. A preparation method of the IgG antibody affinity peptide-alkaline phosphatase fusion protein comprises the following steps of: firstly, connecting an IgG antibody affinity peptide gene with an alkaline phosphatase gene to construct a recombinant vector; secondly, carrying out electrotransformation on Pichia pastoris; thirdly, screening a high copy expression strain with G418 resistant pressure; fourthly, culturing the strain, and carrying out induced expression; and fifthly, extracting the purified IgG antibody affinity peptide-alkaline phosphatase fusion protein.

The invention discloses a preparation method of an antibody-conjugated medicine, the antibody-conjugated medicine and applications. The preparation method comprises the following steps: firstly, underthe catalysis of Sortase A enzyme, leading LPXTG sequence and oligoglycine linker to generate transpeptidation reaction, so that the anti-CD20 monoclonal antibody is connected with a first linker arm; and then leading an azide group linker and alkynyl linker to generate cycloaddition reaction, so that the first linker arm is connected with a second linker arm. The antibody-conjugated medicine isprepared by utilizing an enzyme-chemical method, so that the usage amount of expensive medicines can be reduced, and the cost can be saved. By adopting difunctional small molecules, the steric hindrance of Sortase A enzyme in transpeptidation reaction can be reduced, and the flexibility is good. The conjugation sites and quantity on the antibody medicines can be efficiently controlled, the uniformity is enhanced, and the in-vivo and in-vitro anti-tumor activity can be improved on the basis of keeping the original antibody affinity.

The invention relates to the biotechnology field, and more specifically, the invention discloses a human monoclonal antibody against IgE, a preparation method and a purpose thereof. According to the invention, a natural human phage antibody library of large capacity is constructed;; a human antibody 2E19 strain against IgE is obtained through screening from the library; an amino acid sequence of a heavy chain variable region is expressed as SEQ ID NO: 6; and the amino acid sequence of a light chain variable region is expressed as SEQ ID NO: 8. Besides, the invention also discloses the preparation method of the antibody 2E19, as well as a nucleotide sequence for encoding the antibody 2E19 and an expression vector and a host cell comprising the nucleotide sequence. The antibody 2E19 of the invention has a higher antibody affinity, so as to be able to obviously inhibit degranulation caused by the combination of IgE and FC epsilon RI on a cell surface, and the antibody 2E19 does not combine with the IgE combined with the FC epsilon RI on the cell surface. The antibody 2E19 of the invention could be used for the preparation of a medicine for treating hypersensitivity diseases, especially for treating allergic asthma.

The invention discloses a VEGF (Vascular Endothelial Growth Factor) resistant antibody belonging to the fields of biotechnology and immunology and application of the VEGF resistant antibody. Amino acid sequences of three complementary determining regions (CDR) of heavy chain variable regions of the antibody are respectively shown as SED ID NO. 1, SEQ ID NO. 2 and SEQ ID NO. 3; the amino acid sequences of the three complementary determining regions of light chain variable regions of the antibody are respectively shown as SEQ ID NO. 4, SEQ ID NO. 5 and SEQ ID NO. 6. According to the VEGF resistant humanized antibody, specific targeting combines with VEGF antigens, and an antibody affinity is 3.11*10<-10>, the binding capacity of the antibody and the antigens is high; the VEGF resistant humanized antibody has a good biological activity and can inhibit cell proliferation of vascular endothelial cells, obviously inhibit tumor growth, and effectively inhibit the growth of corneal neovascularization, and can be used for preparing targeted medicines of specific targeting VEGF antigens or angiogenesis inhibiting medicines.

The invention discloses an antibody. The antibody can be bound to an RBD region of a S1 subunit of a Spike protein of a novel coronavirus SARS-CoV-2, so that the activity of binding between a host cell membrane surface receptor ACE2 and the Spike protein is blocked; the antibody is a neutralizing fully-human-derived antibody; and the antibody comprises a heavy chain VH and a light chain VL, and both the VH and the VL have variable regions CDR1, CDR2 and CDR3. The invention also relates to related application of the antibody, in particular to preparation of a complete IgG antibody and an affinity-matured antibody and application of the corresponding antibody in treatment and / or prevention of the novel coronavirus SARS-CoV-2. The fully-human-derived scFv single-chain antibody obtained by screening and the IgG antibody thereof can recognize and bind the RBD region of the Spike protein, can effectively block the activity of binding between ACE2 and the Spike protein, are non-toxic to cells, and can remarkably inhibit a cytopathic effect caused by virus infection, and after the affinity of the antibody is mature, both the affinity of the antibody and the blocking effect on the Spike protein and the ACE2 are obviously enhanced.

The invention provides methods identifying individuals suitable for treatment for lupus and methods of monitoring treatment, based on measuring antibody affinities, as well as of treating lupus based on measuring antibody affinities. The treatment entails administration of a conjugate comprising a non-immunogenic valency platform molecule and at least two double stranded DNA epitopes, such as DNA molecules, which bind to anti-DNA antibodies from the patient.

The invention relates to the field of biotechnologies, in particular to a New Delhi metallo-beta-lactamase-1 (NDM-1) aptamer, its screening method and application. The aptamer provided in the invention can combine with NDM-1 by high affinity and high specificity, can be used for NDM-1 bacterium detection, and can greatly shorten the detection time, thus laying a foundation for an aptamer-based clinical rapid diagnosis technology of NDM-1. The aptamer provided in the invention has antibody affinity equivalent to that of traditional antibodies, and the production process is simpler, and the cost is lower, so that the aptamer can substitute traditional antibodies and be used in a rapid diagnosis method of metallo-beta-lactamase.

The invention discloses a 25-hydroxyvitamin D analysis method based on combination of immune purification and mass spectrum detection. The method mainly comprises steps of preparing a biotin-labeled antibody, preparing a biotin-labeled antibody-coated magnetic bead, enriching and purifying a sample and carrying out mass spectrum detection. The analysis method is advantaged in that high specificityof antibody affinity is utilized, 25-(OH) D can be specifically enriched and purified from a complex biological sample, moreover, respective accurate detection of 25-(OH) D2 and 25-(OH) D3 is realized, the antibody coupled magnetic bead enrichment method is combined with mass spectrum detection, so high flux, sensitivity and accurate quantification are realized, moreover, use efficiency of a liquid phase mass spectrum system is greatly improved.

The invention provides a monoclonal antibody TBEF3 of tubercle bacillus-resistant secretory antigen target protein in early stage. The monoclonal antibody TBEF3 is prepared by the following steps: selecting a specific antigen peptide mouse; collecting sensitized mouse B lymphocyte and mouse myeloma cell to fuse; judging positive clones by using an enzyme linked immunosorbent assayelisa and an immunoblotting testing method; establishing a hybridoma cell line TBEF3 for secreting monoclonal antibody of tubercle bacillus-resistant secretory ESAT-6 in early stage; carrying out multiplication culturing on the positive cells and injecting to congenic mouse enterocoelia for induction of generation of ascitic fluid containing antibody; and carrying out collection and antibody affinity purification to obtain the monoclonal antibody TBEF3 of tubercle bacillus-resistant secretory antigen target protein in early stage. The invention also provides an application of the monoclonal antibody in testing the secretory antigen target protein of mycobacterium tuberculosis in early stage.

The invention discloses a microfluidic chip for separating neuroblastoma (CTC) and a capture method thereof, relates to a microfluidic chip for separating CTC, and aims to enable CTC cells to be quickly enriched and captured in the chip. The method provided by the invention realizes one-step separation and capture of the neuroblastoma CTC from whole blood based on the critical sorting size of fluid mechanics in physics and the antigen-antibody affinity effect in biochemistry, reduces the operation steps, and improves the capture efficiency and cell activity of the neuroblastoma CTC. The methodhas the advantages that one-step operation is achieved, and complex pretreatment is not needed; 2, the capture efficiency and purity of CTC are improved through two-stage separation; 3, the CTC cellswith high efficiency and high activity are finally obtained under the dual capture action; 4, the cells can be put under the microscope for observing and detecting.

The present invention provides a method for altering a T cell mediated pathology in a patient. This method comprises administering a composition comprising at least one and / or two chimeric proteins. Each chimeric protein comprises at least a portion of either the Valpha or Vbeta region of a TCR from particular T cells from a patient having a T cell mediated pathology, and an immunoglobulin constant region. The genes encoding Valpha and / or Vbeta regions and the genes encoding immunoglobulin constant regions are isolated and inserted into an expression vector. The chimeric proteins are produced by introducing the expression vectors into insect cell lines. The chimeric proteins are purified using antibody affinity columns, and then chemically conjugated to an immunogenic carrier, keyhole-limpet hemocyanin (KLH). Since the conjugates comprises chimeric proteins made specifically from particular T cells from a patient having T cell mediated pathology, when it is administered to such a patient, with or without a cytokine, such as granulocyte-macrophage-CSF, or a chemokine, it can induce immune responses to alter such a T cell mediated pathology.

The invention discloses a method for detecting antibody affinity. The detection method mainly includes the steps of (1) antigen-coated microspheres, (2) detection of antibody affinity and (3) data processing. The method for detecting antibody affinity has the advantages of simplicity, quickness, high sensitivity, good repeatability, more stable and reliable detection results, and the like.

The present disclosure describes systems and methods to make predictions classifying one or more properties of a binding protein such as an antibody, for example, antibody affinity or specificity for an antigen. The system can include one or more machine learning models that can extrapolate complex relationships between amino acid sequence and function. The system can be trained on high-quality training data generated through a two-step single-site and combinatorial deep mutational scanning approach. The trained models can then make predictions on novel variant sequences generated in silico. The present disclosure describes amino acid sequences generated by the systems and methods provided, and uses of the generated sequences to produce proteins for therapeutic and diagnostic use.

The invention belongs to the technical field of chemiluminescence biology, and particularly relates to a fluorescence resonance energy transfer technology which is applied to detection of antigen-antibody affinity interaction. The invention provides an FRET (Fluorescence Resonance Energy Transfer) detection technology which comprises the following steps: selecting fluorescein isothiocyanate (FITC) and Rhodamine B as fluorescent markers, pretreating the Rhodamine B and a coupling agent EDC / NHS to activate carboxyl groups, carrying out labeling reaction on fluorescein groups and antigens and antibodies, screening and purifying labeled samples through Sephadex G-25, reacting the labeled antigens and antibodies in an elisa plate, and detecting the fluorescence in the elisa plate. FRET technology is utilized to measure fluorescence intensity, and interaction is detected. The detection technology provided by the invention aims to establish a platform by utilizing a fluorescence labeling technology, is used for screening and detecting the interaction of the antigen and the antibody, is a convenient technology which does not need repeated incubation and washing circulation, can be directly used for reaction detection in a solution, and can be applied to the aspects of antibody preparation, immunotherapy research, protein function detection and the like.

The invention discloses a method for purifying an egg yolk antibody by utilizing an affinity immune medium and belongs to the technical field of foods. According to the method of the invention, a novel antibody affinity immunopurification method is developed by using a diatomite affinity protein label. According to the affinity purification technology, a cheap diatomite filter aid is adopted as acarrier, an antigen protein with a ribosomal protein L2 label is adopted as a coupling ligand, the specific adsorption effect of the ribosomal protein L2 on diatomite is utilized to construct the affinity immune purification method which is low in cost and high in efficiency. The development of the efficient and low-cost specific yolk antibody affinity purification technology can effectively improve the separation and extraction efficiency of specific yolk immunoglobulin, improve the additional value of the egg yolk antibody, and expand the application field of the egg yolk antibody, so that the efficient and low-cost specific yolk antibody affinity purification technology has important significance on improving the competitiveness of the specific egg yolk immunoglobulin in the high-end biological antibody market.

The invention belongs to the field of biology, and discloses a mouse anti-human CD47 monoclonal antibody and a hybridoma cell strain secreting the monoclonal antibody. Specifically, the hybridoma cellstrain secreting the monoclonal antibody in the invention is 3D8. The antibody in the invention comprises a heavy chain variable region and a light chain variable region; the amino acid sequence of the heavy chain variable region is SEQ ID NO:1; and the amino acid sequence of the light chain variable region is SEQ ID NO:2. The antibody provided by the invention is high in affinity, can promote phagocytic action of macrophages on tumour cells by blocking human SIRP alpha and human CD47 signals, and plays an important role in the aspect of human tumour treatment.

The invention discloses a humanized IgM monoclonal antibody standard substance and a preparation method thereof, and the method comprises the following steps: carrying out phage antibody library screening on a virus antigen to obtain an IgG prototype antibody meeting the affinity threshold requirement; after the affinity of the prototype IgG antibody is mature, grafting an optimized antibody heavy chain variable region to a constant region of a human IgM antibody to form a chimeric heavy chain, and unchanging a Kappa light chain; performing expression and purification to obtain a humanized IgM monoclonal antibody standard substance raw material; carrying out purity characterization, protein activity characterization and structure characterization on the humanized IgM monoclonal antibody standard substance raw material; and on the basis that the purity is fully represented and the structure is confirmed to be consistent with the sequence of a target antibody, determining the value of the humanized IgM monoclonal antibody standard substance by adopting an isotope dilution mass spectrometry method based on amino acid analysis through uniformity and stability inspection.