Partial purification and characterization of Syrian hamster interferon.

Syrian golden hamster interferon was made by stimulating secondary or benzo(a)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 lead to metal chelate lead to 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.