Antibody Fragment Booknotes (1)
We conducted a mini literature review to learn more about fragment antigen binding (Fab) antibodies. Here’s what we found:
Fab antibodies around 50 kDa in size are the antigen binding domains of an antibody molecule.¹
Fab are the class of antibody fragments that have been most successful in clinical development and are the most thoroughly explored antibody fragment technology.²
Fab’ are fragments that contain disulfide bridge thiols, whereas fragments lacking the thiol functional group are called Fab.
Fab fragments can be produced through two methods. The first is through enzymatic or chemical cleavage of the antibody. Secondly, they can be produced through the recombinant synthesis of F(ab’)2 antibody fragments followed by chemical reduction of these fragments.¹
These fragments have applications in clinical toxicology, with potential to treat various toxins, such as digoxin. The selected fragments can completely bind digoxin in vivo.³
Recombinant Fab molecules are typically expressed in E. coli or yeast microbial systems.⁴
For Fabs containing the Fc region, Protein A can be successfully utilized for purification.⁴
For Fabs that do not contain an Fc region, mixed mode resins or cation exchangers can be used for capture.⁴
Protein L can be used for purification of antibody fragments, but is not as cost-friendly.⁵
How can Purilogics help?
We offer membrane columns for small-scale antibody purification. Our mini and midi columns can be used with a syringe to purify small volumes of antibody. Our novel Purexa™ PrA membrane columns are particularly well-suited for molecules containing an Fc region.
If you produce Fab fragments through enzymatic or chemical cleavage, our Protein A membranes can be a powerful purification tool for you. We can also help you develop custom purification solutions.
Contact us at bd@purilogics.com or +1 (864) 455-1457 to learn more and try them out!
References
1. Fab Antibody Fragment Production - Fab/Fab’ Expression. Biologics Corp. https://www.biologicscorp.com/fab-fragment-antibody/ (accessed 2022 -02 -14).2. Nelson, A. L. Antibody Fragments. MAbs 2010, 2 (1), 77–83.3. Flanagan, R. J.; Jones, A. L. Fab Antibody Fragments: Some Applications in Clinical Toxicology. Drug Safety 2004, 27 (14), 1115–1133. https://doi.org/10.2165/00002018-200427140-00004. 4. Wagner, M.; Shumway, J.; Castano, J.; Scanlan, C.; Waghmare, R. Challenges and Strategies for the Downstream Purification and Formulation of Fab Antibody Fragments. 2014.5. Dhandapani, G.; Wachtel, E.; Das, I.; Sheves, M.; Patchornik, G. Purification of Antibody Fragments via Interaction with Detergent Micellar Aggregates. Sci Rep 2021, 11 (1), 11697. https://doi.org/10.1038/s41598-021-90966-1 .