immunoglobulin complex, circulating IgD immunoglobulin complex IgD immunoglobulin complex, circulating GO:0071739 IgD antibody Note that an IgD immunoglobulin complex has the function of antigen binding if a suitable antigen is available. cellular_component A protein complex composed of two identical immunoglobulin heavy chains of the IgD isotype and two identical immunoglobulin light chains, held together by disulfide bonds, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. 2010-03-24T01:44:53Z Ascomycota