Cyclamidomycin (Desdanine*), an Inhibitor of Nucleoside Diphosphokinase of Escherichia Coli

Cyclamidomycin (CAM) inhibited the growth of E. coli in a progressive manner even at high concentrations and the effect was abolished by washing the cells in a CAM-free medium. Among cellular macromolecular syntheses, nucleic acid synthesis was most sensitive to CAM. In the presence of CAM, nucleic acid precursors in the cellular pool were not incorporated into nucleic acids but were degraded and released into the medium. The nucleoside diphosphokinase activity of the 100, 000×g supernatant from E. coli was inhibited by CAM, leading to the conclusion that this enzyme is involved in the mechanism of action of this antibiotic.