STUDIES ON THE IMMUNE GLOBULINS OF HUMAN SERUM. II. A STUDY OF THE DISTRIBUTION OF ANTI-BRUCELLA AND ANTI-DIPHTHERIA ANTIBODY ACTIVITIES AMONG GAMMA-SS, GAMMA-IM AND GAMMA-1A-GLOBULIN FRACTIONS.

Abstract

Summary The serum of a subject vaccinated with diphtheria toxoid and two sera from patients recovering from infections with Brucella abortus suis were fractionated and samples consisting of γ ss - (7 S γ), γ 1M - (19 S γ) and γ 1A - (β 2A -) globulins were separately assessed for antibody activity. All three protein species appeared to be serologically active. Particular care was taken with the interpretation of data concerning the γ 1A -globulin samples. The serologic activities of the γ 1A samples could not be explained on the basis of any contamination with γ ss -globulin, and were ascribed to γ 1A -globulin itself. A peculiar feature of the γ 1A anti-Brucella agglutinins here studied was their absence of complement-fixing capacity. It is suggested that future investigations on the physicochemical nature of antibodies be carried out with the knowledge that γ 1A - (β 2A -) globulin constitutes a third class of antibodies, besides the γ ss - (7 S γ) and γ 1M - (19 S γ) classes.