Abstract: A method to efficiently extract and purify a target foreign protein expressed with the use of an E. coli strain from the periplasm is disclosed. The method for producing a protein comprising the steps (a) to (c) below: (a) a step of introducing a gene encoding a target foreign protein into E. coli having modification in a gene associated with maintenance of the outer membrane structure; (b) a step of culturing the E. coli of (a); and (c) a step of recovering a target foreign protein from the periplasmic fraction of the microbial cell after culture.

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 method for purifying an antibody or an antibody fragment containing ?-chain variable region includes adsorbing at least one of the antibody or the antibody fragment onto an affinity separation matrix by contacting a liquid sample with the affinity separation matrix, washing the affinity separation matrix to remove impurities, and separating the at least one of the antibody or the antibody fragment from the affinity separation matrix by using an acetate buffer. The liquid sample includes the at least one of the antibody or the antibody fragment. The affinity separation matrix includes a water-insoluble carrier and a ligand selected from the group consisting of Protein L, a variant of Protein L, a domain of Protein L, and a variant of the domain. The ligand is immobilized on the water-insoluble carrier.

Abstract: The first embodiment of the present invention is a method for purifying an antibody or a substance derive from an antibody, wherein a carrier 1 having an affinity ligand with affinity for the antibody or the substance derived from the antibody and a carrier 2 having a cation exchange group are used to prepare an integrated column 1 connecting a column containing the carrier 1 and a column containing the carrier 2 or a column 2 having the mixture of the carrier 1 and carrier 2, the antibody or the substance derived from the antibody is applied to the column 1 or the column 2, and then the adsorbed antibody or substance derived from the antibody is eluted from the column 1 or the column 2. The second embodiment of the present invention is a method for using a carrier having a cation exchange group, wherein a solution containing an antibody or a substance derived from an antibody is applied to a carrier having a cation exchange group having a carboxyl group-containing ligand and pKa of 4.

Abstract: A method for purifying an antibody or an antibody fragment containing ?-chain variable region includes adsorbing at least one of the antibody or the antibody fragment onto an affinity separation matrix by contacting a liquid sample with the affinity separation matrix, washing the affinity separation matrix to remove impurities, and separating the at least one of the antibody or the antibody fragment from the affinity separation matrix by using an acetate buffer. The liquid sample includes the at least one of the antibody or the antibody fragment. The affinity separation matrix includes a water-insoluble carrier and a ligand selected from the group consisting of Protein L, a variant of Protein L, a domain of Protein L, and a variant of the domain. The ligand is immobilized on the water-insoluble carrier.

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 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 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 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 mixed mode antibody affinity separation matrix comprises an antibody affinity ligand and a cation exchange group on a single separation matrix. According to such a matrix in the first step of a process for purifying an antibody or an Fc-containing target molecule, the antibody as the main target substance of the affinity purification can be purified at high purity, the selective separation properties of monomers can also be improved; and the burden on a subsequent impurity removal step can be reduced with respect to the removal of impurities such as aggregates.

Abstract: Packing a column with a chromatography medium at prescribed compression factor, and then passing a mobile phase through the column packed with the chromatography medium while switching the mobile phase flow direction two or more times. According to the present invention, a small-diameter chromatography column packed uniformly and densely as well as a large-diameter column can be reproducibly prepared. The small-diameter chromatography column prepared in this way has the asymmetry factor of not less than 0.80 and not more than 1.80.

Abstract: The first embodiment of the present invention is a method for purifying an antibody or a substance derive from an antibody, wherein a carrier 1 having an affinity ligand with affinity for the antibody or the substance derived from the antibody and a carrier 2 having a cation exchange group are used to prepare an integrated column 1 connecting a column containing the carrier 1 and a column containing the carrier 2 or a column 2 having the mixture of the carrier 1 and carrier 2, the antibody or the substance derived from the antibody is applied to the column 1 or the column 2, and then the adsorbed antibody or substance derived from the antibody is eluted from the column 1 or the column 2. The second embodiment of the present invention is a method for using a carrier having a cation exchange group, wherein a solution containing an antibody or a substance derived from an antibody is applied to a carrier having a cation exchange group having a carboxyl group-containing ligand and pKa of 4.

Abstract: The present invention produces affinity ligands that make it possible to increase the purity of antibodies themselves, which is the main purpose of affinity purification, and, further, to improve the selectivity for antibody monomers and thereby reduce the load of removing antibody multimers on downstream purification steps. The present invention provides new affinity ligands which are modified proteins obtained by introducing a mutation into a protein to increase the number of acidic amino acids in the amino acid sequence of the protein; methods for designing the modified proteins; methods for producing the modified proteins; and affinity separation matrices containing the modified proteins as ligands immobilized therein.

Abstract: A mixed mode antibody affinity separation matrix comprises an antibody affinity ligand and a cation exchange group on a single separation matrix. According to such a matrix in the first step of a process for purifying an antibody or an Fc-containing target molecule, the antibody as the main target substance of the affinity purification can be purified at high purity, the selective separation properties of monomers can also be improved; and the burden on a subsequent impurity removal step can be reduced with respect to the removal of impurities such as aggregates.