[Action of heliomycin on the incorporation of labelled protein precursors and nucleic acid in Staphylococcus aureus cells]. / Deistvie geliomitsina na vkliuchenie mechenykh predshestvennikov belka i nukleinovykh kislot v kletki Staphylococcus aureus

In concentrations of 0.05-0.10 gamma/ml geliomycin suppresses inclusion of C14-uracyl into the acid-soluble fractions of the staphylococcal cells. Inclusion of C14-leucine at the same concentrations of the antibiotics was suppressed to a lesser extent. The above concentrations of geliomycin had practically no effect on inclusion of C14-thimine. Suppression of C14-uracyl inclusion was observed in 5 minutes of the cell incubation with the antibiotic, a significant decrease in C14-leucine inclusion being observed only in 30 minutes of the incubation. The effect of geliomycin on the staphylococcal cells within the concentrations inhibiting the microbial growth and suppressing inclusion of labeled uracyl and leucine into the cells was of the bacteriostatic nature. It was supposed that the antibacterial effect of geliomycin was based on suppression of RNA synthesis.

[Effect of heliomycin on protein and nucleic acid synthesis in Escherichia coli]. / Izuchenie deistviia geliomitsina na sintez belka i nukleinovykh kislot Escherichia coli

Heliomycin at a concentration of 100 mcg/ml had almost no effect on the growth of Escherichia coli, which was inhibited only upon the combined action of heliomycin and ethanol that facilitated the penetration of the antibiotic into the cell. Heliomycin inhibited in these conditions the synthesis of RNA and had no effect on the synthesis of DNA in the three studied strains of E. coli. The synthesis of protein either was not inhibited by heliomycin at all or was inhibited only to a small extent.

[Action of heliomycin on protein and mucleic acid synthesis in Staphylococcus aureus]. / Deistvie geliomitsina na sintez belka i nukleinovykh kislot u Staphylococcus aureus

Heliomycin inhibited synthesis of RNA in Staph. aureua which was clearly shown in the study of the antibiotic effect on RNA synthesis in the lag phase of the culture development: heliomycin markedly lowered the maximum RNA level in the biomass observed in the culture at the beginning of the exponential growth. On further growth of the culture heliomycin induced a significant retardness of the process of the natural decrease in the RNA biomass level resulting in increased content of RNA in the cells growing in the presence of heliomycin as compared to the control culture. Retarded natural decrease in the RNA biomass level in the presence of heliomycin was observed also on the antibiotic addition just at the beginning of the exponential growth, during the period of maximum RNA accumulation in the cells. Heliomycin had no effect on synthesis and biomass levels of DNA. Heliomycin inhibited the protein synthesis and was close to chloramphenicol by the level of inhibition of the summation protein synthesis in the biomass. However, comparison of the effect of the above antibiotics on synthesis of beta-galactosidase, an individual enzyme protein showed that heliomycin was much less active as an inhibitor of protein synthesis in comparison to chloramphenicol.