Physicochemical characteristics of IME-inhibitor of interferon activity from mouse embryo tissues

Further investigation with the inhibitor of interferon activity (IME) isolated from mouse embryo tissue is reported. The present results bring some new data concerning the physiochemical properties of the interferon antagonist. It is not dialysable, not sensitive to trypsin, lysozyme, hyaluronidase, RNAse and pH 2, but is sensitive to pH 10 and neuraminidase. Concentrated and partly purified tissue antagonist of interferon was separated on a column with Sephadex G 100. Three distinct, well separated fractions showing antiinterferon activity were obtained. The characteristics and molecular weight of each of these fractions were determined.