摘要 |
NEW MATERIAL:The physiologically active polypeptide having amino acid sequence of formula. USE:An antitumor agent having lymphotoxin activity. PREPARATION:For example, a lymphotoxin(LT)-producing cell such as human lymphocyte is collected, whole RNA is extracted e.g. by guanidine hydrochloride process and mRNA is separated by sucrose density gradient centrifugation. A complimentary cDNA is synthesized with a reverse transcriptase using the mRNA as template and is integrated into a proper plasmid by a conventional method to obtain a recombinant plasmid, which is inserted into E.coli, etc., to effect transformation of the cell and produce a cDNA library. The library is cloned with a synthetic probe and the cloned DNA is cut from the clone with a restriction enzyme and linked to a manifestation vector. The product is inserted into E.coli and cultured. The compound of formula can be separated from the cultured product. |