Antibody fragmentation is the biochemical or genetic cleavage of antibodies into smaller fragments. This process is used in various laboratory and clinical applications, as fragments retain the specific targeting capabilities of full monoclonal antibodies while altering physiochemical features. This can be beneficial for developing therapeutic agents with distinct properties or to reduce the size of the antibody while retaining its antigen-binding capabilities.
For example, smaller fragments can penetrate tissues inaccessible to full-size antibodies, as well as being easier and more economical to manufacture due to the lack of glycosylation, since it allows the use of prokaryotic expression systems. However, fragmentation without Fc domains may experience rapid degradation within the human body, as the Fc domain is responsible for stabilizing full-size antibodies and enabling FcR-mediated recycling.1
There are several different types of fragments available, such as small monovalent antibody fragments (Fab, scFv) and engineered variants (diabodies, triabodies, minibodies and single-domain antibodies). Antibody fragments have been adapted for use in creating multivalent and multispecific reagents, linked to therapeutic cargos, and enhanced for therapeutic effectiveness.2,3
Common antibody fragments include:
Fab (Fragment, Antigen-Binding): The Fab fragment is generated by cleaving an antibody molecule with the enzyme papain. It consists of the variable regions of both the heavy and light chains, along with part of the constant region of the antibody. Fab fragments retain the antigen-binding capability of the original antibody and are often used in research and diagnostic applications.
Single-Chain Variable Fragment (scFv): An scFv is a smaller antibody fragment that includes both the variable regions of the heavy and light chains linked together as a single polypeptide chain. ScFvs are often used in biotechnology and medical applications due to their smaller size and potential for engineering into various formats.
VHH or Single-Domain Antibodies (sdAbs): VHHs consist of a single variable domain derived from heavy-chain antibodies found in camelids and some cartilaginous fish. Their small size and remarkable stability offer excellent tissue penetration. They maintain high specificity and affinity for their antigens, and they are amenable to genetic engineering, enabling the development of novel constructs tailored for specific applications, such as targeted drug delivery, in vivo imaging, and as probes for various biomolecular studies.
At Biointron, we are dedicated to accelerating your antibody discovery, optimization, and production needs. Our team of experts can provide customized solutions that meet your specific research needs. Contact us to learn more about our services and how we can help accelerate your research and drug development projects.
Holliger, P., & Hudson, P. J. (2005). Engineered antibody fragments and the rise of single domains. Nature Biotechnology, 23(9), 1126-1136. https://doi.org/10.1038/nbt1142
Bates, A., & Power, C. A. (2019). David vs. Goliath: The Structure, Function, and Clinical Prospects of Antibody Fragments. Antibodies, 8(2), 28. https://doi.org/10.3390/antib8020028
