Creative Biolabs offers our expertise in constructing bispecific fusion proteins for your research purposes. We work closely with our customers so as to design every project according to their individual requirements.
Bispecific fusion protein is a major bispecific antibody format and it is generated by linking other proteins to the antibody or antibody fragments to add more functionality or specificity. The source of antibody fragments can be derived from scFv or monospecific Fab dimer. The linker protein can be specific receptors of lymph cells (such as T cell, B cell or macrophage); a second Fab molecule; or a strong and specific ligand of a receptor on tumor cells. Besides that, human serum albumin or albumin binding proteins can also be fused with antibody fragments to extend their serum half-life in vivo. Some of bispecific fusion proteins has been explored as a pre-targeting strategy for imaging and radioimmunotherapy. Compared with BsAb conjugates, the bispecific fusion proteins are engineered and generated by recombinant expression.
We offer our client many different types of bispecific fusion proteins including:
To create bispecific antibodies with higher valency, the Dock-and-Lock (DNL) method can be used. This type of BsAbs are engineered by utilizing the strong and specific natural protein-protein interactions. Benifiting from the higher valency, they are potential molecules used in imaging and radioimmunotherapy.
Bispecific TCR is a type of TCR-based bispecific molecules. It comprises of two parts, engineered TCR targeting tumor cells and functional scFv targeting T cell marker. Similarly to the MOA of BiTE, bispecific TCR redirects the T cells to cancer cells.
For small bispecific molecules, one approach to improve the pharmakinetics is to bind or fuse with long-circulating serum proteins such as human serum album (HSA). The albumin fusion strategy has been used to engineer various BsAbs including BsAb fragments such as scFv-HSA-scFv, scDiabody-HSA, tandem scFv-HSA, etc.
BsAb-toxin fusion proteins are the extension of immunotoxin which consists of a protein toxin, working as the cytotoxic portion, fused to the portion of an antibody. Among which, tandem scFv-toxin is the most reported format, also known as bispecific ligand-directed toxin (BLT). The catalytic toxins, such as pseudomonas exotoxin (PE) and diphtheria toxin (DT) are usually selected as the cytotoxic portion.
With years of experience in antibody engineering and our most devoted scientists, Creative Biolabs has gained significant knowledge in BsAb engineering. we are confident to deliver you a bispecific fusion protein that can meet your specific requirements.
1. Spiess, C.; et al. “Alternative molecular formats and therapeutic applications for bispecific antibodies.” Molecular immunology. 2015, 67(2): 95-106.
2. Kreitman, R.J.; Pastan, I. “Antibody - fusion proteins anti-CD22 recombinant immunotoxin Moxetumomab Pasudotox.” Clin Cancer Res. 2011,17(20): 6398-405.
3. Müller, D.; et al. “Improved pharmacokinetics of recombinant bispecific antibody molecules by fusion to human serum albumin.” J Biol Chem. 2007, 282(17):12650-60.