摘要 |
NEW MATERIAL:A physiologically active polypeptide expressed by the formula. USE:A carcinostatic agent. PREPARATION:For example, a novel human tumor necrotic factor (TNF) gene capable of coding a polypeptide expressed by the formula using a base sequence of a structural gene part of a human TNF precursor cDNA as a base plate is designed and synthesized to respectively link a translation starting codon with the 5'-side and two translation completing codons with the 3'-side. Furthermore, cleavage parts by restriction enzymes are provided on the upstream part on the 5'-side ad downstream part on the 3'-side to readily link to a vector plasmid. The resultant plasmid is then linked to a suitable vector to prepare a recombinant plasmid, which is then inserted to transform a host microorganism. The transformed microorganism is then cultivated in a culture medium to separate the formed product from the culture and afford the polypeptide expressed by the formula. |