immunoglobulin A

immunoglobulin A
immunoglobulin im`mu*no*glob"ulin ([i^]m`m[-u]*n[-o]*gl[o^]b"[-u]*l[i^]n) n. (1953) any one of a class of globular proteins which are antibodies and are produced by the immune system in animals.

Note: The immunoglobulins form a series of related proteins which are each composed of two pairs of polypeptide chains, called heavy (H) and light (L, meaning of lower molecular weight), all linked together by disulfide bonds. They are subdivided on the basis of the structural and antigenic properties of the H chains into four subgroups, {immunoglobulin G} (IgG), {immunoglobulin A} (IgA), {immunoglobulin M} (IgM), and {immunoglobulin D} (IgD). They are divided also into subclasses. Both H and L chains of anny given class and subclass have regions which are of constant structure within that class, as well as regions which are of variable structure. The variable regions impart the ability to recognize and bind to specific molecular structures, thus providing the organism the capacity to recognize and defend itself against the harmful effects of substances foreign to the body. --Stedman

Syn: Ig. [PJC]

The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Immunoglobulin A — (IgA) is an antibody playing a critical role in mucosal immunity. More IgA is produced in mucosal linings than all other types of antibody combined. [cite journal |author=S Fagarasan and T Honjo |title=Intestinal IgA Synthesis: Regulation of… …   Wikipedia

  • Immunoglobulin A — A major class of immunoglobulins found in serum and external body secretions such as saliva, tears, and sweat as well as in the gastrointestinal, respiratory, and genitourinary tracts. Abbreviated IgA. * * * immunoglobulin A n IGA …   Medical dictionary

  • immunoglobulin A — noun one of the most common of the five major classes of immunoglobulins; the chief antibody in the membranes of the gastrointestinal and respiratory tracts • Syn: ↑IgA • Hypernyms: ↑immunoglobulin, ↑Ig, ↑immune serum globulin, ↑immune gamma… …   Useful english dictionary

  • Immunoglobulin A — Schematische Darstellung des Immunglobulin A als Dimer: H Kette (1), L Kette (2), J Kette (3) und Sekretionsstück (4). Als Immunglobulin A (IgA) bezeichnet man einen Antikörper, der hauptsächlich in den externen Körperflüssigkeiten (zum Beispiel… …   Deutsch Wikipedia

  • immunoglobulin A nephropathy — IgA n …   Medical dictionary

  • Selective immunoglobulin A deficiency — Infobox Disease Name = PAGENAME Caption = The dimeric IgA molecule. 1 H chain, 2 L chain, 3 J chain, 4 secretory component DiseasesDB = 29569 ICD10 = ICD10|D|80|2|d|80 ICD9 = ICD9|279.01 ICDO = OMIM = 137100 MedlinePlus = 001476 eMedicineSubj =… …   Wikipedia

  • Linear immunoglobulin A dermatosis — Linear IgA dermatosis is a very rare autoimmune blistering disorder, which manifests via blistering of the skin and the mucous membranes. An autoimmune disorder is a malfunction of the body s immune system causing the body to attack its own… …   Wikipedia

  • secretory immunoglobulin A — secretory IgA; the predominant immunoglobulin in secretions (oral, nasal, bronchial, urogenital, and intestinal mucous secretions and tears, saliva, and milk), a dimer containing the J chain and the secretory component (SC) …   Medical dictionary

  • Immunoglobulin — A protein produced by plasma cells and lymphocytes. Immunoglobulins are an essential part of the body s immune system which attach to foreign substances, such as bacteria, and assist in destroying them. Abbreviated Ig. The classes of… …   Medical dictionary

  • immunoglobulin — im mu*no*glob ulin ([i^]m m[ u]*n[ o]*gl[o^]b [ u]*l[i^]n) n. (1953) any one of a class of globular proteins which are antibodies and are produced by the immune system in animals. Note: The immunoglobulins form a series of related proteins which… …   The Collaborative International Dictionary of English

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