Isolation of Early Viral Proteins from Poxvirus-Insfected Chick Embryo Fibroblasts by DNA-Cellulose Chromatography and Inhibition of Their Synthesis by Chicken Interferon

Up to seven early poxvirus-specific proteins have been isolated from vaccinia-WR-infected and cowpox-virusinfected chick embryo fibroblasts by affinity chromatography on native DNA-cellulose columns. The proteins have been characterized by one dimensional sodium dodecyl sufate/polyacrylamide gel electrophoresis and by non-equilibrium pH-gradient electrophoresis. The molecular weights of the viral proteins were determied by coparison with proteins of known molecular weight and are comparable to several of the vaccinia-WR-specific DNA-binding propteins isolated previously from infected l-929 cells by Solosky J. M., Esteban M. and Holowczak J. A [J. Virol. 25, 263–273 (1978)]. The viral proteins binding reversibly to native DNA have been classified as immediate early viral gene products. Synthesis of cowpox-virus-induced early DNA-binding proteins is inhibited in chick cells pretreated with homologous interferon at a concentration of 500–1000 units/ml.