Innovative production technique for antibody-enzyme

A method for producing a κ light chain antibody, the method comprising:

• an expression step of expressing a κ light chain antibody in an intracellular or extracellular expression system by using an expression vector including a polynucleotide that encodes the κ light chain antibody;
• a first purification step of obtaining a crude purification product containing the κ light chain antibody from an expression product obtained by the expression step by column chromatography using a column containing a first filler;
• an addition step of adding metal ions to the crude purification product containing the κ light chain antibody so as to obtain a crude purification product containing a κ light chain antibody complex in which the κ light chain antibody and the metal ions are bonded;
• a second purification step of obtaining a purification product of the κ light chain antibody complex from the crude purification product containing the κ light chain antibody complex obtained after the addition step by column chromatography using a column containing a second filler;
• and
• a removal step of removing the metal ions from the purification product of the κ light chain antibody complex obtained after the second purification step so as to obtain a purification product of a κ light chain antibody.

A κ light chain antibody, comprising:

• a polypeptide selected from the group consisting of the following (4a) to (7c) as a variable region,
• (4a) a polypeptide having an amino acid sequence represented by SEQ ID NO:
• 4;
• (4b) a polypeptide having an amino acid sequence which is obtained by substitution, addition, or deletion of one or more amino acids in the amino acid sequence represented by SEQ ID NO:
• 4 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue;
• (4c) a polypeptide having an amino acid sequence which shares 90% or more identity with the amino acid sequence represented by SEQ ID NO:
• 4 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue;
• (5a) a polypeptide having an amino acid sequence represented by SEQ ID NO:
• 5;
• (5b) a polypeptide having an amino acid sequence which is obtained by substitution, addition, or deletion of one or more amino acids in the amino acid sequence represented by SEQ ID NO:
• 5 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue;
• (5c) a polypeptide having an amino acid sequence which shares 90% or more identity with the amino acid sequence represented by SEQ ID NO:
• 5 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue;
• (6a) a polypeptide having an amino acid sequence represented by SEQ ID NO:
• 6;
• (6b) a polypeptide having an amino acid sequence which is obtained by substitution, addition, or deletion of one or more amino acids in the amino acid sequence represented by SEQ ID NO:
• 6 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue;
• (6c) a polypeptide having an amino acid sequence which shares 90% or more identity with the amino acid sequence represented by SEQ ID NO:
• 6 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue;
• (7a) a polypeptide having an amino acid sequence represented by SEQ ID NO:
• 7;
• (7b) a polypeptide having an amino acid sequence which is obtained by substitution, addition, or deletion of one or more amino acids in the amino acid sequence represented by SEQ ID NO:
• 7 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue;
• (7c) a polypeptide having an amino acid sequence which shares 90% or more identity with the amino acid sequence represented by SEQ ID NO:
• 7 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue.

A κ light chain antibody, comprising:

• a polypeptide selected from the group consisting of the following (9a) to (9c) as a variable region,
• (9a) a polypeptide having an amino acid sequence represented by SEQ ID NO:
• 9;
• (9b) a polypeptide having an amino acid sequence which is obtained by substitution, addition, or deletion of one or more amino acids in the amino acid sequence represented by SEQ ID NO:
• 9 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue;
• (9c) a polypeptide having an amino acid sequence which shares 90% or more identity with the amino acid sequence represented by SEQ ID NO:
• 9 and in which the 95th amino acid residue from the N-terminal of a variable region by the Kabat classification is deleted or substituted with an amino acid residue other than a proline residue.