Structure of the IgG subclasses

IgG: immunoglobulin G; FR: framework region; VL: variable region of light chain; VH: variable region of heavy chain; CL constant region of light chain; CH1: constant region of heavy chain 1; S-S: disulfide bond; H: hinge region; CH2: constant region of heavy chain 2; CH3: constant region of heavy chain 3; CDR: complementarity-determining region; V: variable region; D: diversity segment; J: joining segment; CHS: coding region at the C-terminal end of a secreted immunoglobulin heavy chain; H1: hinge region 1; H2: hinge region 2; H3: hinge region 3; H4: hinge region 4.