A crystalline fragment from human gamma-globulin

PAPAIN hydrolysis of rabbit γ-globulin has yielded a crystallizable polypeptide fragment with a molecular weight of approximately 80,000 which has no antibody activity¹. Although analogous fragments have been crystallized from purified human myeloma globulins², crystallization of a similar fragment from normal human γ-globulin thus far has not been reported. By performing the papain hydrolysis in relatively concentrated solutions of human γ-globulin, however, a crystalline polypeptide fragment has been obtained. Some work on this γ-globulin fragment is reported here.