Expression in Escherichia coli of chemically synthesized gene for a human immune interferon

A 450 base pair fragment of double stranded DNA consisting of a gene for a human immune interferon (146 amino acid residues), initiation and termination signals plus appropriate restriction endonuclease sites was totally synthesized. The synthesis involved preparation of 62 oligodeoxyribonucleotides by rapid, solid phase procedures, and enzymatic ligation of the oligonucleotides. This synthetic gene was expressed in E. coli under the control of the lac UV5 promoter. Molecular weight of IFN-gamma produced by E. coli was estimated to be about 32,000 and 17,000 dalton by gel filtration and SDS-polyacrylamide gel electrophoresis respectively, suggesting that a dimer-form molecule was expressed in E. coli.