Immunoglobulin

Immunoglobulins are antibody molecules. They are proteins used in the immune response to identify and neutralize bacteria and viruses. There are five classes of immunoglobulin - IgA, IgD, IgE, IgG and IgM. All of the classes have two identical heavy chains which are bound to two identical light chains. The classes are distinguished by their structure and function, where for example, IgM is a pentamer and IgA is a dimer. Each class plays a different role in adapive immune response.