Three Fractions

Porter digested γ-globulins with papain, a proteolytic enzyme, and recovered 3 fractions: Fractions I and II of molecular weights between 50 and 55KDa retained the antigen binding capacity, whereas fraction III, of 80 KDa was crystallizable, and had a higher carbohydrate content (Porter RR, Biochem J. 73:119-127, 1959).