Immunoglobulin G(IgG) Fab 2 Heavy and 2 Light chains VL 2 Fab and 1 Fc fragment CH1 4 Subclasses (IgG1,IgG2,IgG3, CL IgG4) ▣Mol.Wt.150,000 CH2 ~70-75%of serum Fc immunoglobulin. The major antibody of the CH3 secondary immune response Change in affinity with timeImmunoglobulin G (IgG) ◼ 2 Heavy and 2 Light chains ◼ 2 Fab and 1 Fc fragment ◼ 4 Subclasses (IgG1, IgG2, IgG3, IgG4) ◼ Mol. Wt. 150,000 ◼ ~70-75% of serum immunoglobulin. ◼ The major antibody of the secondary immune response ◼ Change in affinity with time Fab Fc VH CH1 CH2 CH3 VL CL