Structure and function of immunoglobulins.

Article Details

Citation
Copy to clipboard

Schroeder HW Jr, Cavacini L

Structure and function of immunoglobulins.

J Allergy Clin Immunol. 2010 Feb;125(2 Suppl 2):S41-52. doi: 10.1016/j.jaci.2009.09.046.

PubMed ID
20176268 [ View in PubMed
]
Abstract

Immunoglobulins are heterodimeric proteins composed of 2 heavy and 2 light chains. They can be separated functionally into variable domains that bind antigens and constant domains that specify effector functions, such as activation of complement or binding to Fc receptors. The variable domains are created by means of a complex series of gene rearrangement events and can then be subjected to somatic hypermutation after exposure to antigen to allow affinity maturation. Each variable domain can be split into 3 regions of sequence variability termed the complementarity-determining regions (CDRs) and 4 regions of relatively constant sequence termed the framework regions. The 3 CDRs of the heavy chain are paired with the 3 CDRs of the light chain to form the antigen-binding site, as classically defined. The constant domains of the heavy chain can be switched to allow altered effector function while maintaining antigen specificity. There are 5 main classes of heavy chain constant domains. Each class defines the IgM, IgG, IgA, IgD, and IgE isotypes. IgG can be split into 4 subclasses, IgG1, IgG2, IgG3, and IgG4, each with its own biologic properties, and IgA can similarly be split into IgA1 and IgA2.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Immunoglobulin heavy variable 1-2P23083Details
Immunoglobulin heavy variable 3-30P01768Details
Immunoglobulin kappa variable 2D-28P01615Details
Immunoglobulin kappa variable 1-17P01599Details
Immunoglobulin lambda variable 3-21P80748Details
Immunoglobulin heavy constant gamma 3P01860Details
Immunoglobulin heavy constant epsilonP01854Details