[Purification of the bacterial ribosome using chloramphenicol and erythromycin columns]

Chloramphenicol and erythromycin are antibiotics whose target is the bacterial ribosome. We have studied the possibility of isolating the bacterial ribosome by affinity chromatography on chloramphenicol and erythromycin columns. Several columns have been prepared using different spacers and methods of attachment of the ligands (cyanogen bromide, bis-expoxyde). The efficiency and specificity of these columns is discussed. Ethylene diamine is not always suitable as a spacer, because it presents non specific affinity for the ribosome. Pure tight ribosomes have been prepared by ultracentrifugation. They have been compared to ribosomes from affinity columns. These columns have no denaturing effect on ribosomes. They allow a good purification of ribosomes starting from crude bacterial extracts, but the separation of tight couples from loose subunits is not possible.