Figure 1.

Cartoon representations of IgG-single-chain Fv (scFv) fusion antibodies. (a) Example of a bivalent bispecific antibody (BisAb) formed with the full construct of one parental monoclonal antibody (mAb) linked to scFv fragments derived from the VH and VL antigen-binding domains of a separate parental mAb. Gly/Ser linker peptides are shown as curvy lines. Interchain IgG and interdomain scFv disulfides are represented as red diploids. (b) Fusion of scFv fragments to different parental mAb heavy chain sites yield four unique, symmetrical BisAb formats