Figure 2. Available formats of BsAbs. Conventional IgG consists of 2 heavy chains and 2 light chains linked by 4 disulfide bonds. Heavy chain Ab is only comprised of heavy chains. Most bsAbs consist of Ab-based fragments, such as scFv, sdAb (nanobody), Fv, Fab, and Fc. Some non-Ab-based proteins, such as TCR, receptor, and ligand can be components of bsAbs. (A) Examples of tandem scFv-based bsAbs. (B) Examples of asymmetric IgG-based bsAbs. These bsAbs are constructed by paring 2 different heavy chains and lights chains (heterodimeric bsAbs). (C) Examples of multiple domains assembled with Fc. Fc domain is conjugated with scFvs, BiTE, or DART.
DART, dual affinity retargeting.