What are immunoglobulins?

Any of a group of large glycoproteins that are secreted by plasma cells and that function as antibodies in the immune response by binding with specific antigens. There are five classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM. (Dictionary) For the source and more detailed information concerning your request, click on the related links section (Answers.com) indicated at the bottom of this answer box.