Mode of Action of Enomycin, an Antitumor Antibiotic of High Molecular Weight

III. On Weak Inhibition of Polyphenylalanine Synthesis Directed by Polyuridylic Acid

抄録

The effect of enomycin, a polypeptide antibiotic and an inhibitor of protein synthesis of mammalian cells, on polyphenylalanine synthesis directed by added polyuridylic acid was studied with ribosomal system of Ehrlich ascites carcinoma cells. Phenylalanine polymerizing reaction stimulated by poly U was weakly but significantly inhibited by enomycin at the concentration which displayed a marked inhibition on the in-corporation of phenylalanine by endogenous messenger RNA.
The binding of phenylalanyl-sRNA to ribosomes was enchanced by added poly U, and was weakly suppressed by enomycin. The forma-tion of poly U-ribosomes complex was also blocked by enomycin slightly to the same degree.
The results suggested that enomycin might inhibit the formation of the poly U-ribosomes complex and also the binding of phenylalanyl-sRNA to the complex.