Kyowa Hakko Kirin Co., Limited

Kyowa Kirin Co., Ltd.

Mami Tsuchiya

Rinpei Niwa

Takuya Murakami

Yuta Tezuka

According to the present invention, a heterodimer protein composition that is composed of a first polypeptide comprising an immunoglobulin heavy chain constant region and a second polypeptide comprising CL-Fc prepared by fusion of an immunoglobulin light chain constant region (CL) and Fc region, and also has a deletion or substitution of Cys residues involved in disulfide bonds between CL and CH1, a purification method of the protein composition thereof, a preparation method of the protein composition thereof, a DNA and a vector encoding the protein composition thereof are provided.

Heterodimer protein composition

Among N-glycoside-linked sugar chains which are bound to the Fc region of an antibody, sugar chains which are bound to Asn at position 297 relates to the activity and stability of the antibody in blood, but there is a possibility that extra sugar chains bound to the amino acid residues at positions other than 297 have influences upon the antibody constant region-mediated activity and a possibility of causing a problem of uniformity as a therapeutic antibody preparation. Accordingly, among N-glycoside-linked sugar chains which bind to the Fc region of the antibody, a method for controlling extra sugar chains which are bound to Asn residues at positions other than position 297 according to the EU index is required. The present invention provides an antibody variant composition, comprising amino acid residues of an Asn-X-Ser/Thr (X represents an amino acid residue other than Pro) sequence at positions other than positions 297 to 299 according to the EU index in an Fc region of a human IgG antibody, in which at least one amino acid substitution selected from an amino acid substitution of Asn to other amino acid residue, an amino acid substitution of X to Pro and an amino acid substitution of Ser/Thr to other amino acid residue is carried out, and a fragment of the antibody variant composition.

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Tokyo, Japan

Mami Tsuchiya