Creative Biolabs is pleased to introduce an unparalleled de novo single domain antibody sequencing service, which has been developed, based on our world-leading platform of de novo antibody sequencing using our proprietary Database Assisted Shotgun Sequencing (DASS) technology. Soluble and functional single domain antibody can be sequenced by subunit with 100% coverage and dozens of successful cases proving 100% accuracy.
Single domain antibody (sdAb) is a kind of antibody fragments consisting of a monomeric antibody variable domain (VH) and lacking the light chain and CH domain of the heavy chain in conventional Fab region of an IgG. The first sdAb was derived from the VHH domain of heavy-chain antibodies (HCAbs) identified in camelids (llama, alpaca, camel, dromedary, etc.). The VNAR domain of cartilaginous fish (e.g. shark) antibodies (known as IgNAR, immunoglobulin new antigen receptor) is another qualified source for sdAb development. An alternative approach is to split the dimeric variable domains from normal IgGs of humans or mice into monomers by camelizing a few critical residues.
Fig. 1 Structural comparison between conventional IgG and camelid HCAb.
Similar to conventional antibodies, sdAbs are able to bind selectively to a specific antigen. sdAbs can be easily produced in bacteria or yeast in large quantities with high stability, as well as antigen binding affinities and specificities. With the size in the nanometer range, sdAbs take great advantages of stability and penetrability, which are essential for the development of antibody-based drugs or diagnostic tools.
Fig. 2 Structural comparison between conventional IgG and shark IgNAR.
Advantages of sdAbs
With the most advanced DASS technology, Creative Biolabs provides services helping customers obtain the sequence information of sdAbs, which plays key roles in the development of therapeutic or diagnostic sdAbs. Our world-leading de novo antibody sequencing platform can achieve successful sequencing of sdAbs with diverse origins with 100% coverage and 100% accuracy. For instance, the full length of the camelid heavy chain antibody (HCAb) sequence could be obtained by mass spectrometric de novo sequencing. Leu/Ile ambiguities could be resolved by homology comparisons with known VHH sequences. Moreover, sdAb conjugates or immobilized sdAbs can be successfully sequenced through our DASS technology as well.