New polypeptide, its production, vector therefor and medicine containing the same

PURPOSE: To produce a polypeptide having biologically high activity by inserting a specifically modified interferon-γ gene into a suitable Escherichia coli expression vector and expressing a polypeptide by using the expression vector. CONSTITUTION: An interferon-γ gene is inserted into an M13-vector and a single- stranded DNA is isolated from the vector. Then, the DNA is hybridized with an oligonucleotide in a mutagenesis mixture to generate a position-specific base interchange forming a stop codon in a coded region of the interferon-γ gene. The modified interferon-γ gene is isolated, then a polypeptide is expressed from the gene by using a suitable Escherichia coli expression vector and isolated to obtain a prescribed polypeptide. COPYRIGHT: (C)1989,JPO