Fig. 4A: Structure of the Antibody IgG
The Fab portion of the
antibody has specificity for binding an epitope of an antigen. The Fc portion
directs the biological activity of the antibody. In the case of IgG, the Fc
portion can bind to phagocytes for enhanced attachment (opsonization) as well
as activate the classical complement pathway. Antibodies are composed of 4
protein chains: 2 identical heavy chains and 2 identical light chains. Disulfide
(S-S) bonds join the protein chains together.
Last updated: August, 2019
Please send comments and inquiries to Dr.
Gary Kaiser