SPR-BASED BINDING ASSAY FOR THE FUNCTIONAL ANALYSIS OF MULTIVALENT MOLECULES

摘要

Herein is reported a heterodimeric fusion polypeptide comprising a first proteinaceous moiety and a second proteinaceous moiety, wherein the first proteinaceous moiety and the second proteinaceous moiety are the first and the second antigen of a bispecific antibody which comprises a first binding site that specifically binds to the first proteinaceous moiety and a second binding site that specifically binds to the second proteinaceous moiety, wherein the first proteinaceous moiety is fused to the N-terminus of a first antibody heavy chain Fc- region polypeptide of the IgG1 subtype, wherein the second proteinaceous moiety is fused to the N-terminus of a second antibody heavy chain Fc-region polypeptide of the IgG1 subtype, wherein the first and the second heavy chain Fc-region polypeptide form a disulfide-linked heterodimer, wherein one or both of the heavy chain Fc- region polypeptides comprise a tag for immobilization to a solid phase at its C- terminus, and wherein the first and the second Fc-region polypeptide comprise the mutations T366W and T366S/L368A/Y407V, respectively, and the use of said fusion polypeptide for the determination of the avidity-based binding strength of a bispecific antibody, which comprises a first binding site specifically binding to a first antigen and a second binding site specifically binding to a second antigen, to said first and second antigen in a surface-plasmon-resonance-method.