Exploring Antibody Structure

Antibody Molecule Structure

• Disulfide bonds attach the light chains to the heavy chains in an antibody molecule.
• An antibody molecule is composed of two heavy chains and two light chains.

Immunoglobulin (Ig) Domain Structure

• The structure of an immunoglobulin (Ig) domain consists of a β-barrel with a hydrophobic core and a β-sheet framework.

B Cell Progeny and Antibody Production

• Plasma cells, a type of B cell progeny, may produce antibodies of other heavy-chain classes.

Light Chain Composition and Function

• The κ (kappa) or λ (lambda) light chain remains fixed throughout the life of each B cell clone.
• Light chains participate in binding and neutralizing microbes and toxins, but do not participate in activation of the complement system.

Antibody Molecule Regions and Functions

• The variable region (Fv) of the antibody molecule contributes most to antigen binding.
• The crystallizable fragment (Fc) region tends to crystallize in solution.
• The hinge region of the antibody molecule allows the two antigen-binding Fab regions to move independently of each other.

Antibody Isotypes and Subtypes

• The IgM isotype of antibody has five subtypes.

Quiz: Understanding the Structure of Antibody Molecules Test your knowledge on the composition of antibody molecules, including the arrangement of polypeptide chains, the presence of variable and constant regions, and the formation of the Y-shaped structure. Explore the role of disulfide bonds in connecting the light and heavy chains.