Abstract: The objective of the present invention is to provide a method for effectively and easily reducing an amount of a specific impurity in a liquid. The method for reducing an amount of a nucleic acid in a liquid according to the present invention is characterized in comprising the steps of contacting the liquid with a water-insoluble magnesium compound to adsorb at least a part of the nucleic acid on the water-insoluble magnesium compound. Also, the objective of the present invention is to provide an adsorbing filter useful for purifying a useful substance, such as an antibody and an antibody-like molecule, used as a purification material for effectively removing an impurity with easily maintaining the yield of the target substance due to excellent adsorption ability to a nucleic acid and low adsorption ability to an antibody, an antibody-like molecule or the like. The adsorbing filter is characterized in comprising the layer comprising a water-insoluble magnesium compound.

Abstract: The objective of the present invention is to provide a method capable of efficiently removing an impurity from an aqueous solution or a suspension comprising an antibody or an antibody-like molecule and the impurity. The method for purifying an antibody or an antibody-like molecule according to the present invention is characterized in treating an aqueous solution or a suspension comprising the antibody or the antibody-like molecule and an impurity with a water-insoluble inorganic compound, wherein the water-insoluble inorganic compound comprises one or more elements selected from magnesium, calcium and aluminum.

Abstract: A carrier for ligand immobilization obtained by shrinking polysaccharide porous beads not less than 10% by a shrinkage rate defined by the following formula, and crosslinking the polysaccharide porous beads: Shrinkage rate (%)=(1?V2/V1)×100 (wherein, V1 indicates the gel volume of polysaccharide porous beads before shrinkage, and V2 indicates the gel volume of polysaccharide porous beads after shrinkage).

Abstract: A carrier for ligand immobilization obtained by shrinking polysaccharide porous beads not less than 10% by a shrinkage rate defined by the following formula, and crosslinking the polysaccharide porous beads: Shrinkage rate (%)=(1?V2/V1)×100 (wherein, V1 indicates the gel volume of polysaccharide porous beads before shrinkage, and V2 indicates the gel volume of polysaccharide porous beads after shrinkage).

Abstract: A process for producing porous cellulose beads of the present invention is characterized by comprising the steps of: a) mixing an alkali aqueous solution and cellulose to prepare cellulose micro dispersion at low temperature, b) adding water to the cellulose micro dispersion to prepare cellulose slurry, and d) bringing the cellulose slurry into contact with coagulation solvent. A carrier for ligand immobilization of the present invention is characterized by being by shrinking polysaccharide porous beads not less than 10% by a shrinkage rate defined by the following formula, and crosslinking the polysaccharide porous beads: Shrinkage rate (%)=(1?V2/V1)×100 (wherein, V1 indicates the gel volume of polysaccharide porous beads before shrinkage, and V2 indicates the gel volume of polysaccharide porous beads after shrinkage).

Abstract: A protein includes an amino acid sequence derived from the sequence of SEQ ID NO: 1, wherein the amino acid sequence includes a substitution of Val at a position corresponding to position 40 of SEQ ID NO: 1 with a polar uncharged amino acid residue, a basic amino acid residue, or Ala. The protein has a reduced antibody-binding capacity in an acidic pH range, as compared to a protein including the amino acid sequence without the substitution.

Abstract: A method for purifying an antibody-like protein includes adsorbing an antibody-like protein onto an affinity separation matrix by bringing the antibody-like protein into contact with the affinity separation matrix; and eluting the antibody-like protein by bringing an eluent having a pH of 3.5 or higher into contact with the affinity separation matrix. The affinity separation matrix includes a carrier and a ligand immobilized on the carrier, and the ligand includes an amino acid sequence derived from a sequence selected from the group consisting of SEQ ID Nos: 1 to 5. Gln or Lys in an Fc-binding site of the amino acid sequence is substituted by Ala, Ser, or Thr, and the ligand has a lower antibody-binding capacity in an acidic pH range, as compared to a ligand including the amino acid sequence without the substitution.

Abstract: A protein includes two or more amino acid sequences, wherein each amino acid sequence is derived from a sequence selected from the group consisting of SEQ ID NOs: 1 to 5. The amino acid sequence closest to the N-terminus includes more Lys residues than the other amino acid sequence(s), and in the amino acid sequence closest to the N-terminus, a total number of Lys in positions 1 to 38 is equal to or greater than a total number of Lys in position 39 and subsequent positions.

Abstract: A protein includes an amino acid sequence derived from a sequence selected from the group consisting of SEQ ID NOs: 1 to 5. The amino acid sequence includes a substitution of a hydrophobic amino acid residue, an acidic amino acid residue, or a polar uncharged amino acid residue with a basic amino acid residue, and the protein has a reduced antibody-binding capacity in an acidic pH range, as compared to a protein including the amino acid sequence without the substitution.

Abstract: A protein includes an amino acid sequence derived from a sequence selected from the group consisting of SEQ ID NOs: 1 to 5. The amino acid sequence includes a substitution of a hydrophobic amino acid residue in an Fc binding site with a different hydrophobic amino acid residue or a polar uncharged amino acid residue, and the protein has a reduced antibody-binding capacity in an acidic pH range, as compared to a protein including the amino acid sequence without the substitution.

Abstract: A method for immobilizing a ligand on a formyl group-containing insoluble base material includes producing an imine by mixing the ligand and the formyl group-containing insoluble base material, and reducing the imine by using a borane complex, wherein the ligand comprises an amino group and has a specific affinity for a target compound, and wherein the borane complex has a Lewis base ligand having pKa of 6.5 or less.

Abstract: An object of the present invention is to develop techniques to create novel engineered protein ligands that maximize the binding capacity and binding efficiency to a target molecule of affinity separation matrices on which the protein ligands are immobilized. The present invention provides protein ligands (variants) that can be immobilized on carriers in a manner shown in schematic FIG. 1(4)-(15), as well as antibody affinity separation matrices obtained by immobilizing such a protein ligand on a water-insoluble carrier. The affinity separation matrices are characterized by their excellent binding capacity and binding efficiency to a target molecule.

Abstract: A process for producing porous cellulose beads of the present invention is characterized by comprising the steps of a) mixing an alkali aqueous solution and cellulose to prepare cellulose micro dispersion at low temperature, b) adding water to the cellulose micro dispersion to prepare cellulose slurry, and d) bringing the cellulose slurry into contact with coagulation solvent. A carrier for ligand immobilization of the present invention is characterized by being by shrinking polysaccharide porous beads not less than 10% by a shrinkage rate defined by the following formula, and crosslinking the polysaccharide porous beads: Shrinkage rate (%)=(1?V2/V1)×100 (wherein, V1 indicates the gel volume of polysaccharide porous beads before shrinkage, and V2 indicates the gel volume of polysaccharide porous beads after shrinkage).

Abstract: An object of the present invention is to develop techniques to create novel engineered protein ligands that maximize the binding capacity and binding efficiency to a target molecule of affinity separation matrices on which the protein ligands are immobilized. The present invention provides protein ligands (variants) that can be immobilized on carriers in a manner shown in schematic FIG. 1(4)-(15), as well as antibody affinity separation matrices obtained by immobilizing such a protein ligand on a water-insoluble carrier. The affinity separation matrices are characterized by their excellent binding capacity and binding efficiency to a target molecule.