233 results about "Protein A" patented technology

A system and method for generating thermostable variants of a protein is disclosed. The system receives a three-dimensional structure of a target protein and identifies mutable regions, including solvent-exposed residues and loop regions. Conserved and active site residues are excluded from mutation through a fixed-position mask. A message-passing neural network (MPNN) generates mutant sequences at unmasked positions, executed under multiple temperature parameters. Design scores based on Shannon entropy and log probability are computed, and high-confidence variants are selected. Predicted structures for selected variants are evaluated using structural and sequence-based features to compute stability scores. A ranked list of thermostable variants is generated. Top candidates undergo molecular dynamics simulations to compute dynamic metrics such as RMSD, radius of gyration, SASA, and ddG, and are re-ranked accordingly. The system enables accurate, constraint-driven protein design with high structural and functional fidelity, suitable for industrial and therapeutic applications.

The invention belongs to the technical field of biological detection, and discloses a kit and a method for quantitatively detecting residual quantity of host cell protein of pichia pastoris in order to solve the problems of limit of quantitation and low detection sensitivity of an existing detection method. According to the present invention, the empty plasmid without the recombinant human serum albumin gene is introduced into the pichia pastoris, and purification is performed by combining the Protein A chromatographic column and the host cell protein coupling affinity column, such that the prepared polyclonal antibody can be effectively used for the quantitative detection of the residual amount of the pichia pastoris host cell protein in the biological product; the kit formed by the polyclonal antibody has good accuracy and repeatability on the quantitative detection of the host cell protein residues in the pichia pastoris source biological products, the quantification limit is 0.2 ng / mL, and the kit provided by the invention can meet the quantitative detection of the host cell protein residues in all the pichia pastoris source biological products.

The present invention provide novel immunofiber compositions for protein or peptide purification and simple and cost-efficient methods and systems using these compositions. In some embodiments, the immunofibers comprise a customized Z-33 peptide derived from Staphylococcus aureus Protein A which is used to construct immuno-amphiphile molecules that assemble into immunofibers in aqueous solution with bioactive epitopes on the surface and have peptide or protein binding ability.

A method and apparatus for inoculating a bioreactor with a C1-fixing strain is disclosed. In particular, the present disclosure relates to the cost-efficient methods and apparatus for inoculating a bioreactor with a C1-fixing strain for production of protein, such as single cell protein or cultured protein, by microbial fermentation of a gaseous substrate.

The invention provides a synthesis method of adsorption resin for removing immune globulin, and relates to a high polymer material synthesis technology, polyethylene glycol (PEG) or sulfobetaine (SBMA) is grafted through RAFT polymerization, the thickness of a grafting layer is 50-150nm, the nonspecific adsorption capacity of albumin is less than 5ng / cm < 2 >, photosensitive groups (such as phenyl azide) and ultraviolet light (254nm) are introduced to trigger crosslinking, and the coating shedding rate is less than 0.5% / time. According to the present invention, the cyclic stability is improved by 2 times, the Protein A directional capture antibody is grafted on the surface of the acrylic resin grafted with the polyethylene glycol or sulfobetaine, the IgG adsorption capacity achieves 150 mg / g, the specificity is more than 95%, the polyethylene glycol (PEG) is grafted on the surface of the magnetic particle by using ATRP / RAFT controllable polymerization, the organic solvent use amount is reduced by more than 80%, and the product adsorption capacity achieves 150 mg / g.

The invention discloses a preparation method of a monomeric protein and hydrophobic transmembrane protein complex, which comprises the following steps: 1) preparing a protein A containing the monomeric protein, the C end of the monomeric protein in the protein A having a connection sequence for connecting with the hydrophobic transmembrane protein; the connecting sequence comprises at least two amino acids; preparing a protein B containing a hydrophobic transmembrane protein monomer; and 2) connecting the protein A with the protein B, and polymerizing the hydrophobic transmembrane protein monomers in the plurality of protein B to form the hydrophobic transmembrane protein, thereby obtaining the monomeric protein and hydrophobic transmembrane protein complex.

A pharmaceutical composition for enhancing radiation therapy, containing a fusion protein dimer is disclosed. The fusion protein dimer includes an IL-2 protein and a CD80 protein. A method of radiation therapy for cancer, using the composition is also disclosed. The composition for enhancing radiation therapy may increase the effect of radiation therapy in cancer treatment.

Provided herein are methods for purifying polypeptides (e.g., antibodies) comprising an Fc region by Protein A chromatography; methods for using wash solutions comprising benzoate and / or benzyl alcohol during Protein A chromatography; and methods for conditioning the harvest using sodium benzoate prior to Protein A chromatography. [Selected Figure] Figure 1

The invention provides a method for detecting an anti-C1 esterase inhibitor neutralizing antibody in a biological sample, and the method mainly utilizes the characteristic that protein A resin is combined with an Fc segment of the antibody to capture the antibody (containing the anti-C1 esterase inhibitor neutralizing antibody), so that the C1 esterase inhibitor and complement component 1s (C1s) in the biological sample after thermal inactivation are removed; furthermore, an antibody (containing a neutralizing antibody) or an anti-C1 esterase inhibitor compound on the protein A resin is subjected to acid dissociation through an acidolysis solution, so that not only can the anti-C1 esterase inhibitor neutralizing antibody existing in a free form in a biological sample be detected, but also the anti-C1 esterase inhibitor neutralizing antibody existing in a combined form in the biological sample can be detected.

To provide a glycan preparation method for preparing labeled glycans quickly from glycoproteins.SOLUTION: A glycan preparation method comprises: a releasing step in which a glycosidase is allowed to act on a glycoprotein immobilized on a solid phase in a container to obtain a released product containing glycans; and a labeling step in which a labeling reagent is added to the released product in the container to obtain a labeled product containing labeled glycans, wherein the glycoprotein is an antibody, the solid phase has on its surface a ligand selected from the group consisting of protein A, protein G, protein L, protein H, protein D, and protein Arp, and the labeling reagent comprises a reducer, a solution and at least one selected from the group consisting of 8-aminopyrene-1,3,6-trisulfonic acid, a sodium salt thereof, and 9-aminopyrene-1,4,6-trisulfonic acid.SELECTED DRAWING: None

Disclosed herein are improved methods for quantifying monoclonal antibody (mAb) titer using Protein A affinity High-Performance Liquid Chromatography (HPLC). The methods address inaccuracies caused by mAb adsorption to sample vial surfaces by incorporating a surfactant into the mobile phase used for sample dilution. This approach enhances the accuracy, linearity, and robustness of the titer assay, making it suitable for process control and quality assessment in biopharmaceutical development and manufacturing. The methods can be applied as a platform approach for various mAb products.

A process for the manufacture of glycosylated p75NTR neurotrophin binding protein (NBP)-Fc fusion protein, comprising: a p75NTR(NBP) portion, having at least 85% sequence identitywith Seq ID No. 2; and an immunoglobulin Fc portion. wherein, the p75NTR(NBP) and Fc portions are connected via a linker, the linker comprises a peptide of formula Gx, where x is 1, 2, 3, 4, 5 or 6 wherein the linker does not comprise or consist of the sequence GGGGS, characterised by expression from CHO cells, wherein cells are harvested within earlier of 30 hours of cell culture viability reaching 75% or, 12 days post inoculation.

A new technique for improving the secretion production of a heterologous protein by a coryneform bacterium is developed, and thus a method for the secretion production of a heterologous protein is provided. A coryneform bacterium having a secretion production ability of a heterologous protein and modified to maintain a phoS gene having a specific mutation is cultured to produce a heterologous protein by secretion.

The present application provides an isolated antigen-binding protein, comprising: a first antigen-binding domain and a second antigen-binding domain, wherein the first antigen-binding domain specifically binds to TNF-like protein A (TL1A), and the first antigen binding domain and the second antigen binding domain are different.

This invention generally relates to methods for enriching antibodies of interest. Specifically, this invention relates to enriching therapeutic antibodies from upstream cell culture processes using protein A chromatography in the form of a centrifugal column for product quality property profiling analysis.

The present disclosure provides a nanobody platform having a high affinity purification on protein A, wherein the nanobodies may incorporate diverse bioactive peptides, lipid or glycoside in its CDR1 and / or CDR3 regions. The present disclosure also provides a peptide-modified nanobody comprising non-toxic bioactive peptides and that exhibit potent anti-tumor activity. Moreover, the peptide-modified nanobody is able to be combined with other technologies, such as but not limited to bispecific antibodies and antibody-drug conjugates. Further, the present disclosure also provides production processes of the nanobodies and their use as a treatment and diagnostic agents.

The present disclosure relates to a method for improving the quality of glycosylated antibody drug conjugates (DAR distribution, stability, etc.) using activated carbon. Specifically, the present disclosure employs hydrophobic interaction chromatography (HIC) column, protein A chromatography, activated carbon stirring, and buffer exchange, alone or in series, to remove free glycosyltransferases. As a result, the purity of the glycosylated antibody drug conjugates is improved, and the degradation of the antibody drug conjugates is prevented. Ultimately, the drug substance (DS) of OBI-902 (anti-TROP2 antibody drug conjugate) and OBI-904 (anti-Nectin-4 antibody drug conjugate) is further determined.

The invention discloses an efficient purification process of a bispecific antibody and a special chromatography system thereof. The efficient purification process of the bispecific antibody comprises the following steps: pretreatment: performing 0.22 mu m microfiltration on a cell culture supernatant to remove cell debris, and performing deep filtration to reduce turbidity to be less than or equal to 1NTU so as to reduce subsequent chromatography medium pollution; carrying out improved Protein A affinity chromatography, namely carrying out affinity chromatography by adopting an agarose medium modified by a recombinant Protein A ligand, taking 20mM Tris-HCl as a loading buffer solution, and taking the pH value of the loading buffer solution as 7.4, taking 100mM citric acid as an elution buffer solution, and taking the pH value of the elution buffer solution as 3.2-3.5; performing mixed mode chromatography: adopting a composite mode medium containing a benzamidine functional group, taking 50mM sodium phosphate as a buffer solution, adjusting the pH value to 6.0-6.5, adjusting the NaCl concentration to 0.1-0.3 M, and specifically removing a double-antibody polymer and a mismatched isomer by utilizing a hydrophobic effect and an ion exchange synergistic effect; and performing nanoscale filtration and terminal treatment: removing viruses by adopting a virus filtration membrane with the aperture of 30nm, and performing 0.22 mu m sterile filtration to obtain a final product. According to the process, the purification efficiency, the yield and the product purity are remarkably improved, and the process is suitable for efficient purification of the bispecific antibody.

A kit for quantitative analysis of C-reactive protein (CRP) according to an embodiment of the present application may comprise: a first composition comprising a hemolytic agent for hemolyzing at least a portion of blood cells in a blood sample; and a second composition comprising an anti-CRP antibody for the antigen-antibody reaction of the CRP contained in the hemolyzed sample. The CRP quantitative analysis kit of the present application can provide a stabilizer which enables a solid-phase dry anti-CRP antibody to be sufficiently redissolved to participate in an immune reaction, so that quantitative analysis of CRP can be highly accurately and accurately performed in a wide concentration range, and storage stability is improved.

A dispersion solution contains a complex of cerium oxide nanoparticle with protein in which a hydrodynamic diameter and zeta potential of the protein are maintained. The dispersion solution is produced by mixing a solution containing the protein with a solution containing a cerium (III) ion or with a cerium (III) salt followed by adding an oxidizing agent thereto.

The application discloses a fusion protein, which comprises an antibody binding domain and an RNA editing domain, wherein the antibody binding domain is a pAG domain, which comprises the functional domains of Protein A and Protein G, and the RNA editing domain comprises a rat APOBEC1 enzyme deamination domain and / or a human ADAR2 enzyme deamination domain. The fusion protein can be used to simultaneously identify RBP targets and provide transcriptome information in the same sample, can characterize the RNA-protein interaction spectrum, has high reliability and sensitivity, is suitable for studying the RBP functions in tissue sections and single cells, and has wide application prospects in the functional mechanism research of RBP in the development and disease processes.

A method of stabilizing a chemokine protein with a C-X-C or a C-C structural motif such as CXCL13 and CCL21 is provided. The method comprises the step of introducing the chemokine proteins into a solution comprising a buffer a non- ionic or amphoteric surfactant; and an aqueous chaotropic agent. A method of detecting a chemokine protein with a C-X-C or a C-C structural motif such as CXCL13 and CCL21 conjugated to antibodies thereto labelled with a fluorescent label in a solution is also provided. The method comprises the following steps: providing a test substrate comprising an elongate nitro cellulose membrane.

Provided herein are improved methods of cleaning protein A chromatography matrices that have previously been used to purify proteins comprising Fc. The methods generally involve washing a Protein A chromatography matrix with a series of three solutions, a first solution comprising an acid, a second solution comprising Tris, and a third solution comprising NaOH (e.g., 0.001-0.075 M NaOH).

The invention relates to application of IGFBP7 in clinical diagnosis of colorectal cancer and application of IGFBP7 as a drug target. The research shows that the expression quantity of IGFBP7 secreted by tumor endothelial cells is continuously reduced in the colorectal tumor formation process related to inflammation. Functional analysis proves that the endothelial-derived IGFBP7 is secreted into a tumor microenvironment and plays a role in resisting angiogenesis. In addition, the CRC cells can actively ingest the vesicles containing the IGFBP7. The IGFBP7 reduces the activity of a TGF-beta1 signal channel by inhibiting the expression of EGR1, thereby inhibiting the proliferation and migration of tumor cells. What is worthy of attention is that VAPA (Vesicle-associated Membrane Protein Associated Protein A) is identified to be a key factor for mediating IGFBP7 vesicles to be transferred to lysosome, and VAPA promotes the degradation of IGFBP7, so that the cancer suppression function of the IGFBP7 is weakened. The endothelial cell-derived IGFBP7 inhibits the progress of CRC (cyclic redundancy check) through an EGR1 / TGF-beta 1 pathway, and VAPA-mediated lysosome degradation limits the cancer inhibition effect of the endothelial cell-derived IGFBP7. The discovery emphasizes that the endothelial cell-derived IGFBP7 is a promising therapeutic target in the field of colorectal cancer.

The invention provides a preparation method and application of a CBD-AL fusion recombinant protein, a variant Z region obtained by site-directed mutagenesis of a B region of SPA is connected in series with a B structural domain of a protein L, codon optimization is carried out, the front end of CBD is introduced into a BamHI restriction enzyme cutting site, a cysteine sequence, a termination codon TAA and an EcoRI restriction enzyme cutting site are added to the tail end of the B region of the recombinant protein L, and the CBD-AL fusion recombinant protein is obtained. BamHI and EcoRI are subjected to double enzyme digestion and then are connected to a PET28a vector subjected to double enzyme digestion, a recombinant protein CBD-AL gene expression vector of a structural domain of strongest binding IgG of protein A and protein L connected with CBD is constructed, the recombinant protein CBD-AL gene expression vector is transferred into an expression strain for amplification culture, an inducer is added for induction, bacterial sludge is collected, purification is performed by cellulose affinity chromatography, and the recombinant protein CBD-AL gene expression vector is obtained. A binding protein which has a cellulose binding function and can bind all types of immunoglobulins and subtypes thereof is prepared.

The invention discloses a bispecific antibody coupling drug targeting CD24 and HER2 and a preparation method and application thereof.The bispecific antibody coupling drug comprises an anti-CD24 heavy chain, an anti-CD24 light chain, an anti-HER2 heavy chain, an anti-HER2 light chain, a tetrapeptide linker and a topoisomerase I inhibitor exatan derivative, the DAR value of the bispecific antibody coupling drug is 9.25, and the anti-CD24 heavy chain, the anti-HER2 light chain, the tetrapeptide linker and the topoisomerase I inhibitor exatan derivative are different. The compound has strong cytotoxicity and internalization ability on breast cancer cells, not only can specifically target tumor tissues, but also can release drugs to kill target cells and adjacent tumor cells, and can significantly inhibit growth of breast cancer tumors. An antibody part DACH023 in the bispecific antibody coupling medicine is the same as a traditional IgG molecule, a traditional monoclonal antibody structure is reserved to the maximum extent, due to the existence of an Fc fragment, a common Protein A column affinity chromatography method can be adopted for purification, and large-scale production and purification are facilitated.

A local-global template search method of multi-domain protein, first, input the three-dimensional structure of each single domain of the multi-domain protein to be assembled, set the number R of templates to be screened in local evaluation; then, score the alignment of each template in the multi-domain protein structure library with each two consecutive domains, respectively calculate the local score of each two consecutive domains from N terminal to C terminal and from C terminal to N terminal, select the template with the highest local score as the optimal local template; then, again for each template in the multi-domain protein structure library, perform local evaluation by structure alignment of each domain and template through TM-align, and calculate the score of the template according to the local score of each single domain, select the top R templates with high score for global evaluation; in global evaluation, the alignment of different domains is not allowed to overlap, select the template with the highest global score as the optimal global template; finally, output the optimal local template and the final full-length template. The application improves the search precision of the template.

The invention belongs to the technical field of chemiluminescence detection, and particularly relates to a kit for detecting a bovine leukemia virus IgG antibody as well as a detection method and application of the kit. A sample treatment solution in the kit is prepared from Protein A, disodium hydrogen phosphate dodecahydrate, monopotassium phosphate, potassium chloride, sodium chloride, casein, mercaptoethanol, Tween-20 and Proclin; and the mark of the magnetic bead is sealed by combining PEG4000 and ethanolamine. Compared with traditional single protein sealing, the sealing mode provided by the invention has the advantages that interference of foreign protein is removed, non-specific binding in a sample is reduced, the background is reduced, and the stability, sensitivity and specificity of detection are improved; compared with a traditional large-proportion diluted sample, the sample treatment liquid has the advantages that excessive IgG in the sample is removed, dilution treatment of an equipment dilution module is not needed in the detection process, manual pre-dilution treatment is also not needed, and the detection efficiency is improved.

To provide a combination of proteins that contains a TlpA mutant and can induce substance interaction by heating.SOLUTION: A protein set for inducing substance interaction in a temperature-dependent manner comprises: a protein set comprising a protein having a binding-inducing peptide bound to the N-terminus or C-terminus of the following protein a, the following protein b, and the binding-inducing protein; or a protein set comprising a protein having a binding-inducing peptide bound to the N-terminus or C-terminus of the following protein b, the following protein a, and the binding-inducing protein; a: a protein comprising the whole or a part of a coiled-coil region of a protein having a specific amino acid sequence, and having mutations indicated by E180R and E250R; and b: a protein comprising the whole or a part of a coiled-coil region of a protein having the specific amino acid sequence and having mutations indicated by R179E and R251E.SELECTED DRAWING: None