Immunoglobulin D

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Immunoglobulin D ( IgD ) is a Y-shaped antibody molecule which is found in the blood serum of vertebrates (except birds ) with a concentration of 0.03 mg / ml - which corresponds to less than 1% of human serum immunoglobulins . Its exact function is still unknown. IgD is found on B lymphocytes . In its free form it is broken down very quickly.


In its antibody function, IgD is part of the B-lymphocyte membrane and is produced when the B-cell leaves the bone marrow . When the B cell is fully activated, both IgD and IgM are produced. IgD binds and activates basophils and mast cells .

The antibody is a monomer (a single molecule), which consists of two long, "heavy" protein chains (also called H-chains, from English heavy ) and two short, "light" chains (also called L-chains, from English light ) consists. It has the shape of a "Y". At the short ends of the Y are the binding sites (paratopes) with which they can bind to the epitopes of the antigens (foreign bodies, for example specific surface structures of bacterial cells ). The molar mass of the H chain is 69,700 Daltons , that of the entire molecule is 160,000 Daltons.


Individual evidence

  1. Kang Chen, Weifeng Xu, Melanie Wilson, Bing He, Norman W Miller, Eva Bengten, Eva-Stina Edholm, Paul A Santini, Poonam Rath, April Chiu, Marco Cattalini, Jiri Litzman, James B Bussel, Bihui Huang, Antonella Meini , Kristian Riesbeck, Charlotte Cunningham-Rundles, Alessandro Plebani, Andrea Cerutti: Immunoglobulin D enhances immune surveillance by activating antimicrobial, proinflammatory and B cell-stimulating programs in basophils . In: Nat Immunol . 10, No. 8, 2009, ISSN  1529-2908 , pp. 889-898. doi : 10.1038 / ni.1748 . PMID 19561614 . PMC 2785232 (free full text).