After years of research, Creative Biolabs has extensive experience in creating bovine monoclonal antibodies with ultra-long CDR3.
Antibodies, or immunoglobulins (Ig), are closely related to the immune system of most animals. They are a type of globulin with immune function that can specifically bind to the corresponding antigen, which is produced by B cells after the body is stimulated by an antigen. Antibodies can bind and inhibit harmful foreign substances and destroy them in a variety of ways. A representative antibody structure includes two heavy chains (HC) and two light chains (LC) connected by disulfide bonds and non-covalent bonds. Both HC and LC have constant regions and variable regions in their structures.
Introduction of Bovine Ultralong CDR H3
The variable region fragments related to antigen binding are complementarity determining regions (CDR). Generally speaking, there are three CDRs on HC and LC. These CDRs usually constitute a circular structure, and the six CDRs together form the antigen binding site of an antibody. The third CDR (CDR H3) of HC is longer than other CDRs and usually plays a vital role in antigen binding. CDR H3 exists as a simple loop structure in most species. However, some antibodies found in dairy cows have ultralong CDR H3. For these rare ultra-long CDR H3 bovine antibodies, it is possible that only CDR H3 plays a role in the process of binding to the antigen, while other CDRs are only related to structural effects.
Structural Features of Bovine Ultralong CDR H3 Antibodies
Although different ultralong CDR H3 bovine antibodies differ in the type and quantity of amino acids, these ultralong CDR H3 have a common stem and node structure. In fact, each antibody also has different structural variations in CDR H3. These structural changes are reflected in the difference in the length of the stem and the direction of the knob. In addition, the number and position of cysteine residues in the knob region of these bovine ultra-long antibodies are significantly different, resulting in a knob region with a unique disulfide bond pattern. Therefore, besides the different amino acid content in the knob region of these antibodies, different stem lengths, knob directions, and disulfide bond patterns also provide the structural diversity of the bovine ultra-long CDR H3 antibody library.
Fig.1 Comparison of normal and ultralong CDR H3 antibody fab fragments. (Haakenson, 2018)
Applications of Bovine Ultralong CDR H3 Antibodies
The special structure of the ultra-long CDR-H3 has aroused the increasing interest of scientists in engineered bovine antibodies. Currently, different peptides such as erythropoietin and ion channel binding toxins have been designed into the knob area. In addition, the unusual structural diversity provided by the stem and knob domains may allow the discovery of new paratopes. It is worth mentioning that the cysteines at many different positions in the bovine heavy chain knob indicate that the number of potential disulfide ring scaffolds in this small domain may be huge, which provides a new direction for identifying antibodies against enzyme active sites, pores, cracks.
With the advanced antibody platform and experienced team of scientists, Creative Biolabs will provide high-quality bovine ultralong CDR H3 related products and services according to your specific needs. Please feel free to contact us for more details.
- Haakenson, J. K.; et al. Diversity in the cow ultralong CDR H3 antibody repertoire. Frontiers in immunology. 2018, 9: 1262.
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