Synthesis of a human leukocyte interferon with a modified carboxy terminus in Escherichia coli

A recombinant plasmid was constructed that results in deletion of eleven COOH-terminal amino acids of human leukocyte A interferon and their replacement by nine unrelated amino acids encoded by the beta-lactamase gene of pBR322. This altered human leukocyte interferon exhibits antiviral activity slightly lower than the natural molecule and appears to be more susceptible to proteolytic degradation as well. These results also confirm the conclusion that the eleven COOH-terminal amino acids are not essential for antiviral or antiproliferative activity.