Abstract: The present disclosure provides a technique for designing an epitope region-bridging biparatopic antibody, and also provides, through this technique, an antibody that has an improved agonist or antagonist function for an antigen or that promotes or enhances a chemical reaction catalyzed by an enzyme serving as an antigen.

Abstract: Finding a protein of a minute amount present on a cell membrane to provide a method for producing an antibody against the protein. Producing an antibody using a protein identified by an identification method including: a labeling step of using a labeling agent comprising at least one selected from bis-iminobiotin compounds and bis-biotin compounds to obtain cells having a labeled protein; a degradation step of preparing a degradation product for an immobilization treatment, the degradation product containing the labeled protein; an immobilization step of immobilizing the labeled protein contained in the degradation product for an immobilization treatment on a stationary phase via a streptavidin mutant; a cleavage step of releasing an analysis sample from the stationary phase on which the labeled protein is immobilized; and an analysis step of analyzing the analysis sample to identify the labeled protein.

Abstract: Finding a protein of a minute amount present on a cell membrane to provide a method for producing an antibody against the protein. Producing an antibody using a protein identified by an identification method including: a labeling step of using a labeling agent comprising at least one selected from bis-iminobiotin compounds and bis-biotin compounds to obtain cells having a labeled protein; a degradation step of preparing a degradation product for an immobilization treatment, the degradation product containing the labeled protein; an immobilization step of immobilizing the labeled protein contained in the degradation product for an immobilization treatment on a stationary phase via a streptavidin mutant; a cleavage step of releasing an analysis sample from the stationary phase on which the labeled protein is immobilized; and an analysis step of analyzing the analysis sample to identify the labeled protein.

Abstract: The present invention provides a method for producing a multimeric protein composed of a monomeric protein, wherein the monomeric protein is obtained by fusing a protein having an immunoglobulin fold structure to a protein that can serve as a subunit structure, the method including the steps of: (A) preparing the monomeric protein having an insoluble granular form in cells of a microorganism; (B) solubilizing the monomeric protein prepared in step (A) with an aqueous solution containing lauroyl-L-Glu; (C) diluting a solution obtained in step (B) in a buffer containing arginine hydrochloride to lower a concentration of lauroyl-L-Glu; and (D) replacing a solvent of a solution obtained in step (C) with a buffer using gel filtration chromatography or the like.

Abstract: Raman spectra of protein solutions having a plurality of concentrations are acquired. An index, which changes according to interaction between protein molecules, is calculated based on a predetermined peak included in the Raman spectra. A threshold of concentration at which protein can be denatured is specified based on change in the index against change in concentration. The threshold is compared with a concentration of the protein solution required as medicine such as antibody drug, and whether the protein solution is suitable as medicine or not is determined. When the concentration required as medicine is equal to or higher than the threshold, for example, it is judged that the protein solution is not suitable as medicine. When the protein solution is not suitable as medicine, analysis can be repeated by changing a condition of the protein solution.

Abstract: The present invention provides a therapeutic or prophylactic agent for systemic inflammatory response syndrome (SIRS), which contains a polypeptide comprising an amino acid sequence the same or substantially the same as the amino acid sequence of the N-terminal domain of pentraxin 3 capable of binding to histone to form a polypeptide aggregate, or a pharmacologically acceptable salt thereof. The present invention also provides a reagent for quantification and a quantification method of histone, which utilize the polypeptide or a pharmacologically acceptable salt thereof. Furthermore, the present invention provides a polypeptide aggregate containing the polypeptide or a pharmacologically acceptable salt thereof and histone and a production method thereof.

Abstract: The present invention provides a method for producing a multimeric protein composed of a monomeric protein, wherein the monomeric protein is obtained by fusing a protein having an immunoglobulin fold structure to a protein that can serve as a subunit structure, the method including the steps of: (A) preparing the monomeric protein having an insoluble granular form in cells of a microorganism; (B) solubilizing the monomeric protein prepared in step (A) with an aqueous solution containing lauroyl-L-Glu; (C) diluting a solution obtained in step (B) in a buffer containing arginine hydrochloride to lower a concentration of lauroyl-L-Glu; and (D) replacing a solvent of a solution obtained in step (C) with a buffer using gel filtration chromatography or the like.

Abstract: It is an object of the present invention to provide a mutant streptavidin wherein the immunogenicity (antigenicity) in mammals of a streptavidin is reduced. The present invention provides a mutant streptavidin, which comprises an amino acid sequence in which (a) the arginine residue at position 72 is substituted with another amino acid residue, and (b) any one or more of the tyrosine residue at position 10, the tyrosine residue at position 71, the glutamic acid residue at position 89, the arginine residue at position 91, and the glutamic acid residue at position 104 are substituted with other amino acid residues, with respect to the amino acid sequence of a core streptavidin as shown in SEQ ID NO: 2, and which has decreased immunogenicity as compared with that of a wild-type streptavidin.

Abstract: It is an object of the present invention to provide a mutant streptavidin wherein the immunogenicity (antigenicity) in mammals of a streptavidin is reduced. The present invention provides a mutant streptavidin, which comprises an amino acid sequence in which (a) the arginine residue at position 72 is substituted with another amino acid residue, and (b) any one or more of the tyrosine residue at position 10, the tyrosine residue at position 71, the glutamic acid residue at position 89, the arginine residue at position 91, and the glutamic acid residue at position 104 are substituted with other amino acid residues, with respect to the amino acid sequence of a core streptavidin as shown in SEQ ID NO: 2, and which has decreased immunogenicity as compared with that of a wild-type streptavidin.

Abstract: The purpose of the present invention is to provide a diabody-type bispecific antibody, which is characterized by having low immunogenicity and high infiltrating activity into tumor tissues, and by being easily mass-produced at a low cost with use of microorganisms, and by being easily altered in function by means of genetic engineering. The diabody-type bispecific antibody shows a more remarkable effect than the conventional diabody-type bispecific antibodies and chemically synthesized bispecific antibodies even in a very low concentration and in the absence of the super antigen.

Abstract: The purpose of the present invention is to provide a diabody-type bispecific antibody, which is characterized by having low immunogenicity and high infiltrating activity into tumor tissues, and by being easily mass-produced at a low cost with use of microorganisms, and by being easily altered in function by means of genetic engineering. The diabody-type bispecific antibody shows a more remarkable effect than the conventional diabody-type bispecific antibodies and chemically synthesized bispecific antibodies even in a very low concentration and in the absence of the super antigen.

Abstract: This invention provides a system for controlling the phenotypic characteristics of cells. A pair of chimeric polypeptides is anchored in the plasma membrane, each of which has a variable region sequence and an effector sequence. The polypeptides are independent in the absence of antigen, but form a stable complex with each other when antigen is provided. This drives the effector sequences together in a manner that produces a receptor activation signal, leading to a phenotypic change. By titrating the amount of antigen present in the environment, the degree of phenotypic change can be regulated. Cells bearing chimeric polypeptides can be used to measure the concentration of antigen or select cells transfected with a therapeutic gene.

Abstract: This invention provides a method for measuring an antigen concentration in a sample, which comprises: preparing VH-domain polypeptide and VL-domain polypeptide of an antibody specific to the antigen; labeling one of the polypeptides with a reporter molecule to form labeled polypeptides, and immobilizing the other polypeptide onto solid-phase to form immobilized polypeptides; contacting the antigen-containing sample and the labeled polypeptides with the solid-phase; and measuring the reporter molecule of the labeled polypeptides bound to the immobilized polypeptides. The present invention permits simpler and quicker sandwich ELISA for measurements of an antigen concentration in high sensitivity.

Abstract: This invention provides a method for measuring an antigen concentration in a sample, which comprises: preparing VH-domain polypeptide and VL-domain polypeptide of an antibody specific to the antigen; labeling one of the polypeptides with a reporter molecule to form labeled polypeptides, and immobilizing the other polypeptides onto solid-phase to form immobilized polypeptides; contacting the antigen-containing sample and the labeled polypeptides with the solid-phase; and measuring the reporter molecule of the labeled polypeptides bound to the immobilized polypeptides. The present invention permits simpler and quicker sandwich ELISA for measurements of an antigen concentration in high sensitivity.