diabody

Usually, Db is comprised of two chains expressed separately, each of which consists of a VH from one antibody and a VL from another antibody. To improve the efficiency of the heterodimerization process, disulfide bond or knobs-and-holes is introduced into the variant domains. In addition, by tandem linking genes in each chain with internal linker, four VH and VL domains can be expressed in tandem and folded as single chain diabody (scDb), which is also an effective strategy for bispecific antibody producton. Furthermore, fusing recombinant variable domains to an Fc region or CH3 domain (scDb-Fc and scDb-CH3) can not only help the chain-pairing process, but also double the valency of the final product. Meanwhile, the increased size can also significantly prolong the half-life of Db in serum.