Fab region

Definition

The Fab region (Fragment, antigen-binding) is the part of an antibody that binds to antigens. It contains the variable regions of both the heavy and light chains of the antibody.

5 Must Know Facts For Your Next Test

1. The Fab region is responsible for the specificity of antibodies in recognizing antigens.
2. Each antibody has two Fab regions, allowing it to bind two identical or different antigens simultaneously.
3. The variable region within the Fab provides a unique binding site for each specific antigen.
4. Fab regions are produced by enzymatic cleavage of antibodies using papain enzyme.
5. Monoclonal antibodies, used in various therapies, are designed to have specific Fab regions targeting particular pathogens.

Review Questions

• What role does the Fab region play in antibody function?
• How many Fab regions does a typical antibody possess?
• Which enzyme is used to produce Fab fragments from whole antibodies?

Related terms

Fc Region: The part of an antibody that interacts with cell surface receptors and complement proteins.

Variable Region: Part of the antibody's structure that varies between different antibodies and determines antigen specificity.

Antigen:

A substance that induces an immune response, specifically recognized by antibodies or T cells.