With unchallenged experience in bispecific antibodies (BsAbs) synthesis, Creative Biolabs has long been well-known in the field of antibody production. We elaborately integrate our multiple platforms for providing customer a desired diabody with high affinity and low immunogenicity for both academic and clinical purposes.
Linking protein components to produce a predictable and rigid structure is a prior condition for producing complex protein assemblies in a predetermined fashion. A majority of the chemical cross linkers available process long and ﬂexible spacers. According to this, the linked proteins have prominent structural ﬂexibility, and the relative orientation and distance between their protein components is mostly unpredictable. Recombinant BsAbs are artificial proteins comprising the antigen- binding domains of two diﬀerent antibodies. They are being widely researched on account of their “two-target” functionality can enhance the therapeutic value of the individual antibodies by inducing hetero-dimerization of antigens. Until now, more than 50 diﬀerent recombinant formats are being created for producing BsAbs and a number of the latter are in various stages of clinical trial against cancers and inﬂammatory diseases.
Figure 1. Diagram of the structure of diabody and its derivatives.
Diabodies are among the smallest of these BsAbs. They are formed by incorporating heavy-chain variable fragments (VH) and light-chain variable fragments (VL) with short “GGGGS” peptide linkers. However, the five-amino-acid linker is too short to span the distance of ~35 angstroms from the VH C terminus to the VL N terminus. Thus, the two VH-linker-VL chains associate to generate a dimer with two antigen binding sites, each contained the VH and VL fragments from the diﬀerent chains.
Figure 2. Diagram of tandem diabody procedure
When the two Fv domains in the diabody are identical, the structure is named as a monospecific diabody. Such diabodies lead to homo-dimerization of target proteins science they are able to simultaneously recognize two identical protein molecules. By the contrast, bispecific diabodies have Fv domains deriving from two diﬀerent antibodies and enable to bridge diﬀerent proteins resulting in their hetero-dimerization.
Based on development of Diabody, some other engineered BsAbs have also been generated including DART, scDiabody, Diabody-CH3, scDiabody-CH3, Diabody-Fc, scDiabody-Fc. DART, the concept developed by MacroGenics, is the format that a disulfide bond is introduced into the diabody. Similarly, in the format of scDiabody, a flexible linker is engineered to connect the two antibody chains. And in order to extend the half-life, some constant regions such as CH3, Fc are combined. Moreover, tandem diabodies, also known as TandAb, are generated by connecting two pairs of VL and VH domains. They are tetravalent with 2+2 antigen-binding valency.
With the well-established diabody generation platform, the experienced scientists here at Creative Biolabs are dedicated to help you develop unique diabody. To meet the requirements of every client, we provide custom diabody and other diabody-based fragments, including TandAb, single-chain diabody, diabody-Fc, etc. We also provide other various services regarding BsAbs development. Please feel free to contact us for more information and a detailed quote.
1. Kim, J. H.; et al. Crystal structures of mono-and bi-specific diabodies and reduction of their structural flexibility by introduction of disulfide bridges at the Fv interface. Scientific Reports. 2016, 6: 34515.
2. Vaquero, C.; et al. A carcinoembryonic antigen-specific diabody produced in tobacco. The FASEB journal. 2002, 16(3): 408-410.