Partial Purification and Characterization of Syrian Hamster Interferon

Roswell Park Memorial Institute, Department of Viral Oncology, Buffalo, New York 14263, U.S.A. Syrian golden hamster interferon was made by stimulating secondary or benzo( )pyrene-transformed embryo cells with Newcastle disease virus. Titres of 1000 to 6000 units/ml of tissue culture fluid were obtained. The ionic properties of this interferon were characterized by chromatography on cation and anion exchangers and also by isoelectric focusing when two components were observed: a major component, pI 5.8 and a minor component, pI 6.6. Hamster interferon was partially purified on a tandem of sorbents of diverse chromatographic bias: anion exchanger metal chelate hydrophobic ligand. The purified preparation had a specific activity of about 1 x 10 6 units/mg protein; the recovery of activity was nearly complete. The apparent mol. wt. of hamster interferon, as estimated by SDS-polyacrylamide gel electrophoresis under non-reducing conditions, is 17000. Crude Syrian hamster interferon preparations had some activity on mouse cells; this heterologous activity was entirely due to a small subpopulation of interferon molecules which could be isolated on phenylagarose. Received 23 July 1980; accepted 22 August 1980.