Paratope

In immunology, a paratope, also known as an antigen-binding site, is the part of an antibody which recognizes and binds to an antigen.

[1][2] Each paratope is made up of six complementarity-determining regions - three from each of the light and heavy chains - that extend from a fold of anti-parallel beta sheets.

The paratopes on B-cell receptors binding to their specific epitope is a critical step in the adaptive immune response.

[3] Thus, many different species have developed ways to bypass this restriction and increase the diversity of possible paratopes.

In cows, an extra-long complementarity-determining region is considered to have an essential role in diversifying paratopes.

An antibody with a circled region depicting where the paratope is found.
1. Antigen-binding fragment (Fab)
2. Antibody crystallizable region (Fc)
3. Heavy chains
4. Light chains
5. Variable region of the antibody. The paratope is the key-shaped section that makes direct contact with the antigen . [ 1 ]
6. Hinge regions