Some Physical Properties of Chick Interferon

Abstract

DESPITE much intensive investigation on the properties of interferon produced in chick tissue, both the molecular weight and the iso-electric point of the active molecule continue to be a source of controversy. Thus Burke¹ reported a value of 63,000 for the molecular weight of interferon produced in the chorioallantoic membrane of fertile hens' eggs and suggested that the isoelectric point was between pH 4.5 and 5.0. Other investigators^2–4, however, have described interferon purified from chick material as having a molecular weight ranging from 80,000 to 20–34,000. Recently, Rotem and Charlwood⁵ on the basis of the sedimentation rates of unrefined interferons in density gradients suggested that the molecular weight of chick interferon might be as low as 13,000–25,000. In further contrast to Burke's findings, interferon has been described by two groups of workers as being a basic protein^3,6.