There are 5 types of Immunoglobulin, which are unique in their functions. These ig or antibodies synthesis in the host as the result of antigens.
IGA, IgM, IgA, IgD, and IgE are different kinds of antibodies. Each antibody has a different function and structure. All antibodies consist of light chains and heavy chains. Some antibodies are bivalent but IgM is pentavalent.
What are the five different types of antibodies?
- IgG Antibody
- IgM antibody
- IgE antibody
- IgA antibody
- IgD antibody
Functions of IgG, IgM IgD, IgA, and IgE antibodies
Functions of IgG antibodies in the body
- This antibody has the highest concentration in serum which is 75%.
- IgG can cross the placenta.
- this immunoglobin is more efficient in precipitation reactions than agglutination reactions.
- This Ig has a further three subclasses.
- It is a pentamer.
- Synthesis in primary response of infection
- It acts as a marker for recent infection.
- Igm activates the complements.
- Its half-life is about 2-3 days.
- IgM has a 0.5-2 g/l concentration in serum.
- This antibody is most efficient in agglutination and complement fixation reactions.
Characteristics of IgD antibody
- Its amount is negligible in serum.
- Immature B.lymphocyte display only IgD antibodies.
characteristics of IgA antibody
- This antibody is dimers in structure.
- Iga is found on mucosal surfaces.
- It cannot cross the placenta.
- Its amount in serum is about 0.8-4g/l.
The function of IgA Antibody
- IgA protects the mucosa surface from bacterial attachments because it is a secretory antibody.
- Iga does not fix the complements.
IgA antibody structure
- Iga is a monomer.
- It has two light chains and two heavy chains.
- IgA antibody is a serum antibody.
Functions of IgE antibodies
- It is produced in a secondary response.
- IgE is produced against Parasitic infection.
- Its concentration is less than 120 IU/ml.