The fractionation of mammalian serum proteins with ether

Abstract

The method of Kekwick and Mackay (1954) for the fractionation of human plasma proteins was used successfully for the separation of the serum proteins of guinea pig, rat, rabbit, cat, dog, monkey, ox, horse and sheep. By variations in pH, ionic strength, temperature and solvent concentration, 3 fractions consisting essentially of a mixture of alpha and beta globulins (G2); gamma globulin (G3) and albumins (AP) were isolated and concentrated. From rat, rabbit, cat, dog, ox and horse serum electrophoretically pure gamma globulin could be prepared from the fraction G3. From the fraction AP electrophoretically pure albumin was prepared from guinea pig, rabbit and sheep; and 98% pure albumin from dog and cat. Tests on the fractions showed that cholesterol was largely concentrated in the fraction G2. The natural antibodies (Salmonella agglutinin) were concentrated in G2 rat, ox, sheep and dog serum; and in G2 and G3 in horse, guinea pig and rabbit serum. It is suggested that the crude albumin might find a use as a vehicle for radioactive isotopes.