Abstract
We established an improved production of an antitumor polypeptide antibiotic, phenomycin (PHM), by using a genetically engineered Escherichia coli. Phenomycin consists of 89 natural amino acids without intramolecular disulfide bridge. PHM gene was synthesized as a fusion gene in which PHM at the C-terminus and the residues 1-20 of Hirudin variant 1 (HV1) at the N-terminus connected by the factor Xa recognition sequence (Ile-Glu-Gly-Arg). E. coli JM 109 transformed with a plasmid containing the synthesized gene expressed a fusion protein and the trypsinization of the fusion protein purified by ultrafiltration and ion-exchange chromatography gave efficiently recombinant PHM at a final yield of 50 mg/liter of culture. This PHM yield was six times higher than that obtained by a natural PHM producing strain of Streptoverticillium baldacci. Recombinant PHM was not distinguishable from natural PHM in all aspects observed.
