标题:GREATLY IMPROVED ACTIVITY OF STAPHYLOCOCCAL RIBOSOMES IN POLYADENYLATE DIRECTED POLYLYSINE SYNTHESIS : AS AN ASSAY SYSTEM FOR INVESTIGATING THEIR SENSITIVITY TO MACROLIDE ANTIBIOTICS
摘要:In polyadenylate directed polylysine synthesis, homologously cell-free extracts containing ribosomes and "s-100"(105, 000×g supernatant) from staphylococcal cells have less than one-half (one-tenth, when the extracts were stored at -80°C within a few weeks) of the activity of the extracts from Escherichia coli Q13. The present study of concerned with further improving the activity of staphylococcal ribosomes. The polylysine-synthesizing ability by staphylococcal ribosomes increased up to about two times as much as that by E.coli Q13 ribosomes, when "s-100" from E.coli Q13 was mixed with staphylococcal ribosomes which had been washed with a high salt HEPES buffer containing 10 mM HEPES, 1mM EGTA, 16mM magnesium acetate, 1.0M ammonium chloride and 0.1 mM dithiothreitol (pH7.6). Polylysine synthesis by the heterologous extracts has an advantage over polyuridylate-directed polyphenylalanine synthesis in the analysis of ribosome sensitivity for macrolide antibiotics, especially erythromycin.