Heterodimer molecule based on CH3 domain, and preparation method and use thereof
The disclosure is directed to a heterodimer molecule, comprising a first polypeptide chain and a second polypeptide chain, and the first polypeptide chain comprises a first CH3 domain of an antibody heavy chain constant region, the second polypeptide chain comprises a second CH3 domain of an antibody heavy chain constant region. Comparing to a corresponding wild-type CH3 domain of a human antibody heavy chain constant region, the first CH3 domain and the second CH3 domain comprise specific substitution mutations combination, for example, for the first CH3 domain: T366W+F405K, and for the second CH3 domain: T366S+L368A+Y407V+K409A.
1. A bispecific antibody comprising heterodimeric CH3 domains, comprising a first polypeptide chain and a second polypeptide chain, wherein said first polypeptide chain comprises a first CH3 domain of an antibody heavy chain constant region, said second polypeptide chain comprises a second CH3 domain of an antibody heavy chain constant region, and comparing to a corresponding wild-type CH3 domain of a human antibody heavy chain constant region, said first CH3 domain and said second CH3 domain comprise amino acid mutations and said amino acid mutations consist of substitution mutations selected from the following groups:
1) said first CH3 domain: T366W+F405K, said second CH3 domain: T366S+L368A+Y407V+K409A;
2) said first CH3 domain: T366W+F405K+D399S, said second CH3 domain: T366S+L368A+Y407V+K409A+K392D;
3) said first CH3 domain: T366W+F405K, said second CH3 domain: T366S+L368G+Y407A+K409A;
4) said first CH3 domain: T366W+F405K+Y349D, said second CH3 domain: T366S+L368A+Y407V+K409A+E357A; and,
5) said first CH3 domain: T366W+F405K+Y349D+S354D, said second CH3 domain: T366S+L368A+Y407V+K409A+E357A;
wherein said amino acid is numbered according to the EU index of the KABAT numbering of the antibody Fc region, and wherein said wild-type CH3 domain of the human antibody heavy chain constant region is a CH3 domain of a human IgG1 heavy chain constant region.
2. A composition, comprising the bispecific antibody according to claim 1 , and optionally a pharmaceutically acceptable carrier or excipient.
3. A nucleic acid molecule, encoding said first polypeptide chain and/or said second polypeptide chain of the bispecific antibody according to claim 1 .