Creative Biolabs is glad to provide single domain antibody (sdAb) stability improvement service for our client all over the world. With the consistent growth of therapeutic sdAb in the global market, it is important for improving the safety, reliability, and stability of the discovered sdAbs. As stability is one of the most important requirements in the application of therapeutic and diagnostic, Creative Biolabs has developed a remarkable platform for sdAb stability improvement which would be helpful for your sdAb discovery and development projects.
Single domain antibodies (sdAbs) are antibody fragment consisting of a single monomeric variable antibody domain, derived from the heavy-chain-only antibodies produced by camelids and sharks, or the specific developed human VH and VL domain. SdAbs, with a molecular weight of only ~15 kDa, are much smaller than other antibodies. Due to the characteristics of small size, simple production, and high affinity, sdAb allows a broad range of applications in biotechnical and therapeutic use. While like other conventional antibodies, the stability is still one important factor for the sdAb, especially for those developed from human VH and VL domain.
The in vitro stability of sdAbs can be defined by two concepts, the physical stability (thermodynamic stability) and the chemical stability (proteolytic stability). In general, sdAbs are known to be signally stable compared with conventional antibodies. However, it is still necessary to extend the application of sdAbs in extreme environments against temperature induced denaturation, pH induced denaturation, protease hydrolysis and mechanical shear stress to achieve a variety of goals of research and investigation.
Fig. 1 Disulfide-bond Stabilized sdAb. (Hagihara et al. 2012)
With years of experience, Creative Biolabs has developed efficient methods to improve the stability of sdAb. On the one hand, an elegant solution is based on two amino acid substitutions within the framework to form an additional intra-domain disulfide bond while having minimal effects on antigen affinity. On the other hand, CDR is grafted onto the stable framework. Commonly, untargeted mutagenesis and phage display screening at appropriately stringent conditions. In addition, a method is provided to predict the proteolytic susceptibility of sdAb and to subsequently increase the proteolytic stability through genetic engineering as well. Meanwhile, we are also flexible enough to discuss the proposal with our customers or follow a published one to fulfill your specific demands.
Fig. 2 Topical Process of sdAb Mutagenesis.
Creative Biolabs has been a long-term expert in the field of sdAb stability improvement. Our service can be tailor-designed to meet your specific needs. Our seasoned scientists are confident in offering the best service for our customers. If you are interested in our sdAb stability improvement service, please do not hesitate to inquire us for more details.