Expression of a bispecific dsFv-dsFv' antibody fragment in Escherichia coli

A bispecific disulfide-stabilized Fv antibody fragment (dsFv–dsFv')consisting of two different disulfide-stabilized Fv antibodyfragments connected by flexible linker peptides was producedby secretion of three polypeptide chains into the periplasmof Escherichia coli. The dsFv–dsFv' molecules were enrichedby immobilized metal affinity chromatography and further purifiedby anion-exchange chromatography. The recombinant antibody constructsretained the two parental antigen binding specificities andwere able to cross-link the two different antigens. The describeddsFv–dsFv' design might be of particular value for therapeuticin vivo applications since improved stability is expected tobe combined with minimal immunogenicity.