| 摘要 |
Among N-glycosidic linkage type sugar chains bound to the Fc region of an antibody, a sugar chain bound to Asn at the 297-position participates in the activity of the antibody and the stability thereof in blood. However, the excess sugar chains other than the sugar chain at the 297-position likely affect the activity mediated by the constant region of the antibody or cause some problems in the homogeneity as antibody drugs. Thus, there has been required a method whereby these excess sugar chains bound to Asn residues other than the Asn residue at the EU index position 297, among the sugar chains bound to the Fc region of an antibody, can be controlled. Disclosed is a modified antibody composition, wherein amino acid residues constituting a sequence Asn-X-Ser/Thr [wherein X represents an amino acid residue other than Pro], said sequence existing at positions other than the EU index positions 297-299 in the Fc region of human IgG antibody, have been subjected to at least one amino acid conversion selected from among an amino acid conversion from Asn to another amino acid residue, an amino acid conversion from X to Pro, and an amino acid conversion from Ser/Thr to another amino acid residue. Also disclosed is a fragment of the aforesaid modified antibody composition. |
