POLYPEPTIDE MODIFICATION METHOD FOR PURIFYING POLYPEPTIDE MULTIMERS

摘要

Disclosed is a method for purifying or producing, by modifying the binding strength to Protein A, a multispecific antibody having binding activity for at least two kinds of antigens, wherein said multispecific antibody is purified or produced at a high purity and efficiency with only a Protein A purification step. The disclosed method for purifying or producing a multispecific antibody is characterized by modifying the amino acid residue of the antibody heavy chain constant regions and/or the antibody heavy chain variable regions. By introducing such amino acid modifications into the antibody, a multispecific antibody which has a modified binding strength to Protein A and has blood plasma retentivity greater than or equal to that of human IgG1 can be acquired at a high purity and efficiency.