Definitions of T Chain

  1. A glycoprotein found in a variety of external secretions ( tears, bile, colostrum) usually complexed to secreted polymeric immunoglobulins ( IMMUNOGLOBULIN A or, less frequently IMMUNOGLOBULIN M). It is derived, by proteolytic cleavage, from the polymeric immunoglobulin receptor ( RECEPTORS, POLYMERIC IMMUNOGLOBULIN) and probably functions to protect the immunoglobulins from proteolysis in the secretions. ( From Rosen et al., The Dictionary of Immunology, 1989)