Drug Design Relating Amebicides to Inhibition of Protein Synthesis.
NEW YORK UNIV N Y SCHOOL OF MEDICINE
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A study of the effect of emetine on protein synthesis in E. histolytica was made on log phase amebas as compared to stationary phase amebas. Sensitivity to emetine was maintained independently of the rate of protein synthesis. Furthermore, both stages of amebas had the same capacity to bind emetine labeled with tritium to ribosomes. The binding of H3 -emetine was not affected by the presence of certain drugs that interfere with energy metabolism, protein synthesis andor ribosomal function, e.g., dinitrophenol, puromycin, shloroquine and acriflavin. In chase experiments it was shown that the stability of the emetine-ribosome binding is due in part to a hydrogen bonding reaction of the C1 atom of the emetine molecule with the chain elongation site. Finally, evidence was obtained that the capacity to bind emetine provides a basis for conferring drug resistance in amebas. A direct correspondence was found between the degree of drug resistance and the number of binding sites for emetine.