Abstract: The invention aims to provide an immunoglobulin-binding protein having improved chemical stability, especially stability against alkali. The object can be achieved by improving stability against alkali by substituting an amino acid residue(s) at a particular position(s) in an immunoglobulin-binding domain such as domain C of protein A derived from a bacterium belonging to the genus Staphylococcus, to another/other particular amino acid residue(s).

Abstract: An Fc-binding protein exhibiting improved alkaline resistance, a method for producing the protein, an antibody adsorbent obtained by immobilizing the protein on a carrier, and a method for separating an antibody using the adsorbent.

Abstract: The present application addresses the problem of providing an Fc-binding protein having an improved antibody separation ability. The present application also addresses the problem of providing a high-accuracy antibody separation method using an insoluble carrier having the protein immobilized thereon. The problems can be solved by: an Fc-binding protein in which at least an amino acid substitution at a specific position therein occurs and which has reduced affinity for an antibody; and an antibody separation method including allowing an equilibration buffer solution to pass through a column in which an insoluble carrier having the protein immobilized thereon is filled to equilibrate the column, adding a solution containing an antibody to cause the adsorption of the antibody onto the carrier, and eluting the antibody adsorbed on the carrier using an elution solution.

Abstract: The present invention addresses the problem of providing FcRn having improved stability with respect to heat and acids, a method for producing said FcRn, an antibody adsorbent in which said FcRn is used, and an antibody isolation method in which said adsorbent is used. The above problem is solved by substituting an amino acid residue at a specific position in an extracellular region of a human FcRn ? chain and/or a ?2 microglobulin region of a human FcRn ? chain by another specific amino acid.

Abstract: The problem to be addressed by the present invention is to provide improved recombinant Fc?RIIb and Fc?RIIa that do not require refolding and exhibit high productivity and thermal stability, and to provide a method for producing the same. Said problem is solved by improved recombinant Fc?RIIb comprising at least the amino acid residues of the extracellular domain of human Fc?RIIb (No. 43 to No. 215 in UniProt No. P31994), wherein, in said amino acid residues, at least one amino acid substitution has occurred at a position corresponding to No. 82, 94, 98, 104, 105, or 139 in UniProt No. P31994. Said problem is also solved by improved recombinant Fc?RIIa comprising at least the amino acid residues of the extracellular domain of human Fc?RIIa (No. 34 to No. 206 in UniProt No. P12318-1), wherein, in said amino acid residues, at least one amino acid substitution has occurred at a position corresponding to No. 73, 85, 89, 95, 96, or 130 in UniProt No. P12318-1.

Abstract: The invention aims to provide an immunoglobulin-binding protein having improved chemical stability, especially stability against alkali. The object can be achieved by improving stability against alkali by substituting an amino acid residue(s) at a particular position(s) in an immunoglobulin-binding domain such as domain C of protein A derived from a bacterium belonging to the genus Staphylococcus, to another/other particular amino acid residue(s).

Abstract: The present invention relates to an Fc-binding protein exhibiting improved alkaline resistance, a method for producing said protein, an antibody adsorbent obtained by immobilizing said protein on a carrier, and a method for separating an antibody using said adsorbent.

Abstract: An object of the present invention is to provide a method for detecting the presence or absence of a disease, the risk of developing a disease, the degree of progression of a disease and/or the degree of progression of aging, in a subject. The present invention achieves the above described object by a method including the following steps (a) to (c): (a) adding a solution containing an antibody obtained from a subject to a column filled with an insoluble carrier on which an Fc-binding protein is immobilized, to allow the antibody to be adsorbed on the carrier; (b) eluting the antibody adsorbed on the carrier using an eluent, to obtain data of a separation pattern of the antibody; and (c) detecting the presence or absence of a disease, the risk of developing a disease, the degree of progression of a disease and/or the degree of progression of aging, in the subject, using the data as an indicator.

Abstract: An Fc-binding protein having at least amino acid residues of the extracellular domain of the amino acid sequence of wildtype human Fc?RIIa (UniProt Accession Number: P12318) wherein the amino acid residues in the domain have an amino acid substitution or deletion at at least a specific position, a method for producing the protein, and an antibody adsorbent using the protein.

Abstract: Provided are: an Fc-binding protein having improved stability, particularly to heat and acid; a method for producing the protein; an antibody adsorbent using the protein; and a method for separating the antibodies using the adsorbent. Specifically provided are: an Fc-binding protein having improved stability to heat and acid, achieved by substituting an amino-acid residue in a specific position in the extracellular region of human FcyRIIIa with another specific amino acid; a method for producing the protein; an antibody adsorbent using the protein; and a method for separating the antibodies using the adsorbent.

Abstract: The present invention addresses the problem of providing FcRn having improved stability with respect to heat and acids, a method for producing said FcRn, an antibody adsorbent in which said FcRn is used, and an antibody isolation method in which said adsorbent is used. The above problem is solved by substituting an amino acid residue at a specific position in an extracellular region of a human FcRn ? chain and/or a ?2 microglobulin region of a human FcRn ? chain by another specific amino acid.

Abstract: The present application addresses the problem of providing an Fc-binding protein having an improved antibody separation ability. The present application also addresses the problem of providing a high-accuracy antibody separation method using an insoluble carrier having the protein immobilized thereon. The problems can be solved by: an Fc-binding protein in which at least an amino acid substitution at a specific position therein occurs and which has reduced affinity for an antibody; and an antibody separation method including allowing an equilibration buffer solution to pass through a column in which an insoluble carrier having the protein immobilized thereon is filled to equilibrate the column, adding a solution containing an antibody to cause the adsorption of the antibody onto the carrier, and eluting the antibody adsorbed on the carrier using an elution solution.

Abstract: The problem to be addressed by the present invention is to provide improved recombinant Fc?RIIb and Fc?RIIa that do not require refolding and exhibit high productivity and thermal stability, and to provide a method for producing the same. Said problem is solved by improved recombinant Fc?RIIb comprising at least the amino acid residues of the extracellular domain of human Fc?RIIb (No. 43 to No. 215 in UniProt No. P31994), wherein, in said amino acid residues, at least one amino acid substitution has occurred at a position corresponding to No. 82, 94, 98, 104, 105, or 139 in UniProt No. P31994. Said problem is also solved by improved recombinant Fc?RIIa comprising at least the amino acid residues of the extracellular domain of human Fc?RIIa (No. 34 to No. 206 in UniProt No. P12318-1), wherein, in said amino acid residues, at least one amino acid substitution has occurred at a position corresponding to No. 73, 85, 89, 95, 96, or 130 in UniProt No. P12318-1.

Abstract: Provided are: an Fc-binding protein having improved stability, particularly to heat and acid; a method for producing the protein; an antibody adsorbent using the protein; and a method for separating the antibodies using the adsorbent. Specifically provided are: an Fc-binding protein having improved stability to heat and acid, achieved by substituting an amino-acid residue in a specific position in the extracellular region of human FcyRIIIa with another specific amino acid; a method for producing the protein; an antibody adsorbent using the protein; and a method for separating the antibodies using the adsorbent.

Abstract: Provided are: an Fc-binding protein having improved stability, particularly to heat and acid; a method for producing the protein; an antibody adsorbent using the protein; and a method for separating the antibodies using the adsorbent. Specifically provided are: an Fc-binding protein having improved stability to heat and acid, achieved by substituting an amino-acid residue in a specific position in the extracellular region of human FcyRIIIa with another specific amino acid; a method for producing the protein; an antibody adsorbent using the protein; and a method for separating the antibodies using the adsorbent.