Inhibitors of the Transfer of Amino Acids from Aminoacyl Soluble Ribonucleic Acid to Proteins

SUMMARY Puromycin, gougerotin, neomycin B, tetracycline, chloram- phenicol, and cycloheximide inhibit protein synthesis in various cell-free systems. Assays designed to determine the mechanism of action of these inhibitors indicat.e (a) that tetracycline inhibits the binding of aminoacyl soluble ribonucleic acid to messenger ribonucleic acid-containing ribosomes; (b) that the aminoacyl nucleoside, puromycin, releases peptide material from peptidyl soluble ribonucleic acid, messenger ribonucleic acid, ribosome complexes while the related aminoacyl nucleoside, gougerotin, blocks this release; (c) that neomycin B alters the binding of aminoacyl soluble ribonucleic acid onto messenger ribonucleic acid, ribosome complexes; (d) that chloramphenicol can compete with a messenger ribonucleic acid for sites on bacterial ribosomes; and (e) that cycloheximide does not influence the binding of aminoacyl soluble ribonucleic acid to ribosomes or the puromycin- dependent release of peptides from pept’idyl soluble ribonucleic acid, messenger ribonucleic acid, ribosome complexes. Aclcnowledgments-We wish to thank Dr. Richard Schweet for his encouragement of this work and Mrs. Ronnie Barker for invaluable technical assistance. REFERENCES