Immunoglobulin

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  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]

From WordNet (r) 2.0 [wn]:

  immunoglobulin
       n : a class of proteins produced in lymph tissue in vertebrates
           and that function as antibodies in the immune response
           [syn: {Ig}, {immune serum globulin}, {immune gamma
           globulin}, {immune globulin}]