ANTIBODY ACTIVITY IN SIX CLASSES OF HUMAN IMMUNOGLOBULINS.

Antibody activity to thyroglobulin was identified in six classes of immunoglobulins in man, that is, in type I and type II, 6.6S gamma-globulins; in type I and type II, beta(2A)-globulins; and in type I and type II, gamma(1)-macroglobulins. These observations indicate that antibody-activity sites are separate from the part of the H chains of immunoglobulin molecules responsible for specific properties of 6.6S gamma-globulin, beta(2A)-globulin, or gamma(1M)-globulin, and, also, are separate from the part of L chains responsible for type I or type II characteristics of immunoglobulin molecules.