Binding of N substituted erythromycylamines to ribosomes

Several N substituted erythromycylamines were evaluated for their ability to inhibit the binding of [¹⁴C]erythromycin to ribosomes. The association and dissociation constants for the binding of each compound to Escherichia coli ribosomes were determined. These studies have resulted in the development of three types of probes for topological studies of the erythromycin binding site and the ribosome: the chemically reactive bromoacetamido, the photoreactive N (2 nitro 4 azidophenyl)glycinamido, and the fluorescent fluorescein isothiocyanate derivatives of 9(S) erythromycylamine.