IgM immunoglobulin complex, circulating
A polymer of five or six IgM core units each composed of two identical immunoglobulin heavy chains of the IgM isotype and two identical immunoglobulin light chains, held together by disulfide bonds; the individual IgM core units are held together via disulfide bonds with a single J chain polypeptide acting as a bridge between two of the polymeric units. Circulating IgM is present in the extracellular space, in mucosal areas or other tissues, or in the blood or lymph.
GO:0042571
immunoglobulin complex, circulating
is_a
GO:0071753
IgM immunoglobulin complex
is_a
IgM antibody
exact