Biologic activity in a fragment of recombinant human interferon alpha.

Abstract
To locate functionally important regions of the interferon (IFN) molecule, recombinant human IFN-.alpha.2 was subjected to proteolytic digestion. The bacterial proteinase thermolysin produced 2 major complementary fragments, HuIFN-.alpha.2-(1-110) and HuIFN-.alpha.2-(111-153). After reduction with 2-mercaptoethanol and separation of the 2 major fragments on NaDodSO4/polyacrylamide gel electrophoresis, antiviral activity persisted in the larger, MW 12,000, fragment consisting of the amino-terminal 110 amino acids.