1150 results about "Protein A" patented technology

A bispecific antibody format providing ease of isolation is provided, comprising immunoglobulin heavy chain variable domains that are differentially modified in the CH3 domain, wherein the differential modifications are non-immunogenic or substantially non-immunogenic with respect to the CH3 modifications, and at least one of the modifications results in a differential affinity for the bispecific antibody for an affinity reagent such as Protein A, and the bispecific antibody is isolable from a disrupted cell, from medium, or from a mixture of antibodies based on its affinity for Protein A.

A method for the ligation of expressed proteins which utilizes inteins, for example the RIR1 intein from Methanobacterium thermotrophicum, is provided. Constructs of the Mth RIR1 intein in which either the C-terminal asparagine or N-terminal cysteine of the intein are replaced with alanine enable the facile isolation of a protein with a specified N-terminal, for example, cysteine for use in the fusion of two or more expressed proteins. The method involves the steps of generating a C-terminal thioester-tagged target protein and a second target protein having a specified N-terminal via inteins, such as the modified Mth RIR1 intein, and ligating these proteins. A similar method for producing a cyclic or polymerized protein is provided. Modified inteins engineered to cleave at their C-terminus or N-terminus, respectively, and DNA and plasmids encoding these modified inteins are also provided.

A method for identifying and isolating cells which produce secreted proteins. This method is based upon a specific characteristic or the expression level of the secreted protein by transiently capturing the secreted protein on the surface of an individual cell, allowing selection of rare cell clones from a heterogeneous population. Also provided is the use of this method to generate cells which produce a desired level of secreted protein or secreted protein of a particular characteristic(s), and organisms which possess such cells. In particular, the method allows rapid isolation of high expression recombinant antibody-producing cell lines, or may be applied directly to rapid isolation of specific hybridomas, or to the isolation of antibody-producing transgenic animals. This method is applicable for any cell which secretes protein.

A method is provided for separating a protein from one or more other proteins using hydroxyapatite chromatography in which the protein does not bind to hydroxyapatite but the other protein(s) does. In some embodiments, a second protein affixed to a solid support has been used previously to purify the protein by affinity chromatography, and small amounts of the second protein are introduced in the sample during this process. The protein being purified can comprise at least one constant antibody immunoglobulin domain. The second protein can bind to proteins comprising such a domain.

A fusion capsid protein comprising a plant virus capsid protein fused to an antigenic polypeptide is used as a molecule for presentation of that polypeptide to the immune system of an animal such as a human. The plant virus capsid protein is that of an alfalfa mosaic virus (AlMV) or ilarvirus.

The present application provides methods of purifying polypeptides having a Fc region, for example, antibodies or antibody fusions, by adsorbing the polypeptides to a Fc binding agent, such as, for example, Protein A or Protein G, followed by a wash with a divalent cation salt buffer to remove impurities and subsequent recovery of the adsorbed polypeptides. The present application also features methods of eluting the purified polypeptide as well as the incorporation of the methods within a purification train. Kits comprising components for carrying out the methods and instructions for use are also provided.

A stent has a body and a surface with at least a portion of the surface comprising metal with a coating thereon. The coating is selected from the group consisting of thiols and disulfides and combinations thereof. The thiols are of the form R-SH and the disulfide of the form R-S-S-R'' where R is an alkyl group and R'' is an alkyl group. The metal is selected from the group consisting of noble metals, silver and copper.

A mutant hydrolase optionally fused to a protein of interest is provided. The mutant hydrolase is capable of forming a bond with a substrate for the corresponding nonmutant (wild-type) hydrolase which is more stable than the bond formed between the wild-type hydrolase and the substrate and has at least two amino acid substitutions relative to the wild-type hydrolase. Substrates for hydrolases comprising one or more functional groups are also provided, as well as methods of using the mutant hydrolase and the substrates of the invention. Also provided is a fusion protein capable of forming a stable bond with a substrate and cells which express the fusion protein.

A method for reducing leaching of protein A during protein A affinity chromatography is described which involves reducing temperature or pH of, or by adding one or more protease inhibitors to, a composition that is subjected to protein A affinity chromatography.

A method of conjugating peptides and proteins by means of glycosyltransferase is provided.

A mutant hydrolase optionally fused to a protein of interest is provided. The mutant hydrolase is capable of forming a bond with a substrate for the corresponding nonmutant (wild-type) hydrolase which is more stable than the bond formed between the wild-type hydrolase and the substrate. Substrates for hydrolases comprising one or more functional groups are also provided, as well as methods of using the mutant hydrolase and the substrates of the invention. Also provided is a fusion protein capable of forming a stable bond with a substrate and cells which express the fusion protein.

The present invention is directed to methods for purifying a non-human antibody, or antigen binding portion thereof, exhibiting weak binding strength and low binding capacity for Protein A chromatography media. In one aspect, a kosmotropic salt solution is employed to promote the hydrophobic interaction between the non-human antibody, or antigen binding portion thereof, and the Protein A ligand, thereby enhancing the binding of the non-human antibody, or antigen binding portion thereof, to the Protein A chromatography media. In another aspect, the concentration of the non-human antibody, or antigen binding portion thereof, in a sample comprising the antibody, or antigen binding portion thereof, exposed to a Protein A chromatography media is increased to enhance the binding of the non-human antibody, or antigen binding portion thereof, on the Protein A chromatography media.

Disclosed are methods and compositions for treating or preventing a Staphylococcus bacterial infection using a non-toxigenic Protein A (SpA) variant.

A method of detecting and isolating cells that produce a secreted protein of interest (POI) that has a T cell receptor variable domain, comprising: a) constructing a cell line transiently or stably expressing a cell surface capture molecule, which binds the POI, by transfecting the cell line with a nucleic acid that encodes such cell surface capture molecule; b) transfecting said cell simultaneously or subsequently with a second nucleic acid that encodes a POI wherein such POI is secreted; c) detecting the surface-displayed POI by contacting the cells with a detection molecule, which binds the POI; and d) isolating cells based on the detection molecule.

The present invention concerns methods and compositions for treating or preventing a bacterial infection, particularly infection by a Staphylococcus bacterium. The invention provides methods and compositions for stimulating an immune response against the bacteria. In certain embodiments, the methods and compositions involve a non-toxigenic Protein A (SpA) variant or an antibody directed thereto.

Media and devices, such as anion exchangers including such media, wherein the media is a membrane having a surface coated with a polymer such as a polyallylamine. The resulting membrane offers stronger binding of protein impurities and superior removal of host cell proteins from biological samples than conventional ligands based on quaternary ammonium salts, including trimethylammonium ligands. Also described is a chromatography scheme and method for purifying monoclonal antibodies, wherein the anion exchange sorber is placed downstream of an affinity column (such as Protein A or Protein G affinity column) and optionally one or more polishing devices such as cationic exchange columns. Little or no dilution of the cation exchanger pool (or affinity column exchange pool where no cation exchanger is used) is necessary to lower the conductivity of the sample. The sorber functions well to strongly bind host cell proteins and other impurities in biological samples even at high conductivities and pH.

A method for producing viral gene delivery vehicles which can be transferred to pre-selected cell types by using targeting conjugates. The gene delivery vehicles comprise: 1) the gene of interest; and 2) a viral capsid or envelope carrying a member of a specific binding pair, the counterpart of which is not directly associated with the surface of the target cell. These vehicles can be rendered unable to bind to their natural cell receptor. The targeting conjugates include the counterpart member of the specific binding pair, linked to a targeting moiety which is a cell-type specific ligand (or fragments thereof). The number of the specific binding pair present on the viral vehicles can be, for example, an immunoglobulin binding moiety (e.g., capable of binding to a Fc fragment, protein A, protein G, FcR or an anti-Ig antibody), or biotin, avidin or streptavidin. The virus' outer membrane or capsid may contain a substance which mediates entrance of the gene delivery vehicle into the target cell. Due to the specificity of the ligand, the binding pair's high affinity, and the gene delivery vehicle's inability to be targeted when used alone, the universality of the method for gene delivery, together with its high cell type selectively can be achieved by using various targeting conjugates.

A variety of zinc finger proteins (ZFPs) and methods utilizing such proteins are provided for use in treating chronic pain. ZFPs that bind to a target site in genes that are aberrantly expressed in subjects having chronic pain are described. In addition, ZFPs that bind to a target site in genes expressed at normal levels in subjects experiencing chronic pain, modulation of whose expression results in decreased pain perception, are also provided. For example, genes that are over-expressed in the dorsal root ganglia (DRG) of pain patients (e.g., Nav1.8) can be repressed.

The present invention relates to methods of purifying and analyzing preparations of Fc domain containing polypeptides comprising binding said polypeptide to protein A, more particularly to a protein A column, and eluting with a pH gradient elution system. This method enhances separation of aggregates, multimers and modified versions of the protein from the single Fc domain containing polypeptide.