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 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: 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: Disclosed is a T7 RNA polymerase mutant having improved thermal stability and/or specific activity in comparison with wild-type T7-like bacteriophage RNA polymerase, wherein at least one amino acid residue corresponding to at least one of the amino acid residues selected from the group at least consisting of glutamine at position 768, lysine at position 179 and valine at position 685 of the amino acid sequence that composes wild-type T7 RNA polymerase shown in SEQ ID NO: 6, is substituted with another amino acid.

Abstract: Disclosed is a T7 RNA polymerase mutant having improved thermal stability and/or specific activity in comparison with wild-type T7-like bacteriophage RNA polymerase, wherein at least one amino acid residue corresponding to at least one of the amino acid residues selected from the group at least consisting of glutamine at position 768, lysine at position 179 and valine at position 685 of the amino acid sequence that composes wild-type T7 RNA polymerase shown in SEQ ID NO: 6, is substituted with another amino acid.