title: Biogenesis of an antitumor antibiotic protein, neocarzinostatin.
abstract: A study of the biogenesis of the antitumor protein antibiotic neocarzinostatin (NCS) was undertaken. The production of NCS, as well as the growth of Streptomyces carzinostaticus in a production medium, was sensitive to puromycin, chloramphenicol, and actinomycin D. However, when a 12-hr culture in production medium was transferred to a nongrowth medium consisting of a phosphate buffer with Mg(2+) and Ca(2+), rapid NCS synthesis and liberation occurred. NCS production in this medium was no longer sensitive to actinomycin D, but was sensitive to puromycin and chloramphenicol. The conversion of a precursor NCS to an active form was shown to occur in this medium. Subcellular analysis suggested that NCS synthesis occurred by a mechanism similar to that of protein synthesis by membrane polysomes.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000903:Antibiotics, Antineoplastic / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000096:biosynthesis; D002250:Carbon Radioisotopes; D003609:Dactinomycin / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D013302:Streptomyces / Q000187:drug effects / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000903:Antibiotics, Antineoplastic; D001426:Bacterial Proteins; D002250:Carbon Radioisotopes; D012333:RNA, Messenger; D003609:Dactinomycin