Isolation of a Biologically Active Fragment of Human Alpha Interferon

Abstract

When treated with pepsin under limited digestion conditions, human leukocyte-derived alpha interferon (HuIFN-α) is partially inactivated. While the initial HuIFN-α preparation is about equally active on human and on bovine cells, the residual antiviral activity of HuIFN-α after pepsin treatment is significantly more active on bovine cells than on human cells. Furthermore, pepsin-treated HuIFN-α, when assayed on bovine cells, yields an active product which is smaller and antigenically distinguishable from the native forms of HuIFN-α.