A protein that acts as an antibody. Immunoglobulins are made by B cells and plasma cells. An Ig is a type of glycoprotein with two heavy chains and two light chains.

Any of the structurally related glycoproteins that function as antibodies. They are divided into five classes (IGA, IGD, IGE, IGG, IGM) on the basis of structure and biological activity.

Glycoproteins found in the blood that function as antibodies; the basic structure is a y shaped molecule consisting of two light polypeptide chains and two heavy polypeptide chains linked by disulfide bonds.

Substances made by the immune system that attack foreign substances. Also known as antibodies.

Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.

(immunoglobulin structure) There are two types of polypeptide chains responsible for the biological and immunological properties of the different immunoglobulins, the heavy chain and the light chain; they are linked by covalent and non-covalent forces to give a four-chain Y-shaped structure based on pairs of identical heavy and light chains; each chain consists of a variable region and a constant region which are coded for by different genes; some immunoglobulin classes occur as polymers of this basic monomer.

Immunoglobulins are glycoprotein molecules that are produced by plasma cells in response to an immunogen. Indications for serum immunoglobulin testing include diagnosis and monitoring of monoclonal gammopathies and immune deficiencies.