12 results about "Antibody variable region" patented technology

The application provides a nanobody targeting human transmembrane activator and calcium modulator and cyclophilin interactor (TACI) and an application thereof, and the antibody is derived from a llama heavy chain antibody variable region. The anti-TACI single-domain antibody NB38 can specifically bind to human TACI with high affinity, can recognize a recombinant TACI protein, can also recognize a TACI with a natural conformation on a cell surface, and can partially block a BAFF / APRIL signal pathway. Based on the nanobody, the application constructs a fusion protein, a chimeric antigen receptor, an effector cell expressing the chimeric antigen receptor, and a double-specific cell linker and other genetically engineered forms. The nanobody can be further extended into a drug coupling form. The product of the application can be used for mediating directional recognition and killing of TACI positive cells, and can be used as a supplement and expansion of BCMA targeted therapy, and provides a new candidate technical scheme for targeted therapy of multiple myeloma and other TACI related diseases.

The application discloses a targeting superantigen fusion protein based on an improved SE(3)-Transformer and an implementation method. In an offline stage, amino acid sequences are first converted into one-hot encoding or language model embedding (such as ESM-2), and are spliced with multiple sequence alignment (MSA) features for geometric initialization. A neural network (improved SE(3)-Transformer) combined with multiple sequence alignment (MSA) and an attention mechanism is constructed to predict the coordinates of C alpha, C, N and O atoms for main chain prediction, and the neural network is trained through a gradient descent method based on a physical heuristic potential item. In a verification stage, the improved SE(3)-Transformer after training is used to generate a predicted structure, conformational stability is verified through a simplified force field, and fine tuning is performed based on a confidence score. The application can accurately predict the structure of a target antigen epitope and an antibody variable region, optimize a superantigen functional domain in combination with a graph neural network, and dynamically design a flexible connecting peptide to realize modular fusion.

The invention relates to the technical field of gene engineering, and particularly discloses a one-step RT-PCR (Reverse Transcription-Polymerase Chain Reaction) kit for amplifying a complete sequence of a variable region of a rabbit-derived antibody and a use method of the one-step RT-PCR kit. The kit comprises an One-Step RT Enzyme Mix, a 5 * One-Step RT Buffer, three pairs of specific amplification primers, a positive control, a negative control and a Nuclease-free Water, and is characterized in that the specific amplification primers are used for amplification of the Nuclease-free Water, and the specific amplification primers are used for amplification of the Nuclease-free Water. The three pairs of primers are designed according to rabbit immune globulin gene sequences and can fully cover heavy chain and light chain variable regions. The use method comprises the following steps: sorting positive B cells from rabbit spleen, cracking single cells, continuously performing reverse transcription and PCR (Polymerase Chain Reaction) amplification in the same reaction system by taking a cracking product as a template, and identifying and cloning the product. The kit can efficiently and specifically obtain the complete sequence of the variable region of the rabbit antibody from the single B cell, and has the advantages of wide coverage, high sensitivity, simplicity and convenience in operation and reliable result.

The application relates to the fields of biological medicine and antibody engineering technology, and particularly relates to a STAT3 hybridoma-derived antibody affinity maturation method based on computational biology, which comprises the following steps: (1) obtaining an antibody variable region sequence; (2) constructing STAT3 antigen and antibody models and evaluating; (3) performing antigen-antibody molecular docking and optimization, and screening out models; (4) performing docking model analysis, and obtaining potential saturation mutation sites; (5) performing site saturation mutation, and obtaining mutation results; (6) performing mutation site analysis, and determining final mutation sites; (7) amplifying a target fragment containing the mutation sites; (8) constructing a recombinant expression vector, and obtaining a reformed STAT3 recombinant antibody through eukaryotic expression and purification; and (9) performing relative affinity determination.

A method for promoting diversification of variable regions of an antibody, particularly a method for promoting diversification of the amino acid sequences of variable regions of an antibody generated by an avian B cell population, the method including suppressing the PI3Kα activity of each avian B cell comprised in the avian B cell population expressing the antibody.

The invention provides a nano antibody targeting human transmembrane activator and calmodulin TACI (transmembrane activator and calmodulin phosphatase) interaction protein and application of the nano antibody. The antibody is derived from an alpaca heavy-chain antibody variable region. The anti-TACI single-domain antibody NB38 can be combined with human TACI with high affinity and specificity, can recognize recombinant TACI protein, can also recognize TACI with native conformation on the surface of a cell, and can partially block a BAFF / APRIL signal channel. Based on the nano antibody, gene engineering forms such as fusion protein, a chimeric antigen receptor, effector cells for expressing the chimeric antigen receptor, a bispecific cell connector and the like are constructed. The nano antibody can be further expanded into a coupled drug form. The product can be used for mediating directional recognition and killing of TACI positive cells, can be used as supplement and expansion of BCMA targeted therapy, and provides a new candidate technical scheme for targeted therapy of multiple myeloma and other TACI related diseases.

The invention relates to the field of artificial intelligence, and particularly discloses an antibody variable region structure prediction method based on structure prior evaluation, which comprises the following steps: S1, screening a high-resolution and high-integrity compound containing a complete antigen and an antibody H / L chain from PDB, and extracting atomic coordinates after processing; s2, calculating geometrical characteristics of a molecular structure and relative spherical polar coordinates of adjacent residues; s3, calculating a structure quality evaluation score according to physical prior and a dihedral angle-atomic spacing mapping formula; s4, screening training data according to scores, and removing low-quality data; s5, constructing an antigen-antibody attribute isomeric graph and initializing a compound graph; s6, embedding related data as enhanced features when the model is initialized; s7, loading an RA-EGN encoder to output a CDR sequence and a 3D coordinate, and splicing a complete antibody structure; and S8, introducing a structure prior loss function fine tuning model, and performing multi-index screening on an optimal result. According to the invention, the problems of low prediction precision and insufficient structure prior utilization of the existing antibody CDR region are solved, and the prediction accuracy of the antibody variable region is improved.

The invention discloses an antibody variable region design method and system based on an electron density generation model, constructs a set of complete process for integrating electron density information into antibody variable region design, and more accurately reduces the conformation of an antibody-antigen compound by introducing molecular dynamics simulation. Generating a series of electron densities of antibody variable regions CDR by using a protein generation model based on the electron densities, and realizing higher structure generation quality through deep mining of original structure information; and a structure prediction model and a high-precision combined free energy calculation method are used to review and screen the generated structure, so that the practicability and success rate of the generated result are improved. Finally, through optional process iteration, the success rate of antibody design is further improved; the development cycle of the high-performance therapeutic antibody is expected to be remarkably shortened, the research and development cost is reduced, and a powerful solution is provided for various dependent antibody treatment methods.

The present inventors have successfully prepared an antigen-binding molecule comprising an antibody variable region that has binding activity against a molecule expressed on the surface of a T cell and a molecule expressed on the surface of any other immunocyte, but does not bind to these molecules at the same time. The present invention allows the preparation of an antigen-binding molecule capable of circumventing adverse reactions that may be caused by the cross-linking of T cells to other immunocytes, and provides an antigen-binding molecule suitable as a drug.

To provide antigen-binding molecules which exhibit effective target-specific cell killing efficacy mediated by immune cells (e.g. T cells) while having reduced or minimal side effects, and to provide a pharmaceutical composition comprising the antigen binding molecule, and a method for producing the antigen-binding molecule.SOLUTION: An antigen-binding molecule capable of binding to multiple different antigens (e.g., CD3 on T cells), but does not nonspecifically crosslink two or more immune cells such as T cells is provided. Such multispecific antigen-binding molecule is capable of modulating and / or activating an immune response while circumventing the cross-linking between different cells resulting from the binding of the conventional multispecific antigen-binding molecule to antigens expressed on the different cells, which is considered to be responsible for adverse reactions when the multispecific antigen-binding molecule is used as a drug.SELECTED DRAWING: None

The invention relates to the technical field of biology, and particularly discloses a method for rapidly screening a high-affinity shark source nano antibody based on a BACTH system. The method comprises the following steps: fusing an antigen and an adenylate cyclase T25 fragment on a pKT25c plasmid, fusing a shark source nano antibody variable region library and an adenylate cyclase T18 fragment on a pUT18tc plasmid, and co-transforming into adenylate cyclase defective escherichia coli BTH101. When the antigen interacts with the nano antibody, the reconstructed adenylate cyclase activates downstream lacZ and chloramphenicol resistance double reporter genes. A blue monoclonal clone with chloramphenicol resistance is screened on a flat plate containing X-Gal, IPTG and chloramphenicol at one time, so that a high-affinity positive clone can be quickly obtained. The method overcomes the defects that a phage display technology is tedious in process, long in period and high in false positive, the whole screening process only needs one week, and the method has the remarkable advantages of being efficient, simple, convenient and low in cost.