<prompt> What is the percentage of immunoglobulins present in proteins?5101520  <response>: Immunoglobulins constitute 20 to 25 of total serum proteins. Based on physiochemical and antigenic differences, five classes of immunoglobulins have been recognized: IgG, IgA, IgM, IgD, and IgE.Ref: Ananthanarayan 9th edition, p93 