Fab fragments are one of the most commonly used BsAb units. Taking advantage of our unchallenged experience in recombinant antibody synthesis, Creative Biolabs is committed to providing customer an expected Fab fragments BsAb with high affinity and low immunogenicity for both academic and clinical purposes.
As a unit of BsAbs, Fab fragment maintains the natural antigen-binding properties of most mammalian immunoglobulins. The native architecture offers the stabilizing interactions of heavy and light chain constant domains, CH1 and CL, respectively. Short of these stabilizing domains may result in compromised thermal stability or solubility and a raised potential for aggregation within BsAbs.
Fig 1. Schematic diagrams of F(ab’)2
A strategy to solve the problem mentioned above is to replace the generally used scFv moiety with a more stable Fab moiety, which may allow BsAb formats more stable and well-behaved. Thus, Creative Biolabs has developed a novel Fab interface which enabled 2 Fab moieties to be expressed simultaneously without heavy chain (HC)/light chain (LC) mixing. Chemical coupling method is one of the most convenient approaches for Fab BsAb synthesis. We possesses outstanding antibody library, which can effectively screen antibody according to customers’ requirements. Taking advantage of our recombinant protein synthesis platform, we can express antibody Fabs in high-quality with either prokaryotic or eukaryotic expression system. According to the mechanism of Ellman’s reaction, disulfide bonds are only introduced between heterodimerized chains, which promise an effective outcome of desired bispecific product.
It has been demonstrated that even with substantial changes to the interface within the Fab moiety based on the Fab designs, the Fab moieities within both the tandem Fab BsAbs and the IgG-Fab are more thermally stable than their scFv counterparts within the tandem scFv BsAbs and IgG-scFv. Like classical IgGs, the Fab-based BsAbs exhibited little to no propensity to produce aggregates, whereas the scFv-based BsAbs both displayed great tendencies toward aggregation. Attenuated stability and a tendency to aggregate may connected with the tandem scFv’s poor expression. According to their biophysical superiority over scFv-based BsAbs, Fab-based BsAbs will be a superior candidate as therapeutic agents. We also provide custom Tandem Fab products for some specific targets.
With our well-established fab fragments BsAb generation platform, the experienced scientists here at Creative Biolabs are dedicated to help you develop unique BsAbs. We also provide other various services regarding BsAbs development. Please feel free to contact us for more information and a detailed quote.
1. Wu, X.; et al. Fab-based bispecific antibody formats with robust biophysical properties and biological activity. MAbs. 2015, 7(3): 470-482.
2. Chames, P.; Baty, D. Bispecific antibodies for cancer therapy. Curr Opin Drug Discov Devel. 2009, 12(2): 276-283.