Structural classes of antibodies

Table 37.3 Structural Classes of Antibodies Secreted antibodies IgG \ / Main antibody in blood; neutralizes toxins; protects fetus and is secreted in early milk. (e.g., tears, saliva, milk, mucus), where IgA \( Abundant in exocrine gland secretions it occurs in dimeric form (shown). Interferes with binding of pathogens / \ to body cells. Membrane-bound antibodies lgE Anchored to surface of basophils, \ / mast cells, eosinophils, and some dendritic cells. lgE binding to antigen induces anchoring cell to release his- tamines and cytokines. Factor in aller- gies and asthma. IgD \{/ B cell receptor. | M | l 9 B cell receptor, as a monomer. \ / Also secreted as polymers of five (left) or six (below). \ / /\