Tracer studies to locate the site of platinum ions within filamentous and inhibited cells of Escherichia coli.

The distribution of platinum ions within Escherichia coli after the induction of filaments with cis-Pt(NH(3))(2)Cl(4), and after growth inhibition by PtCl(6) (2-), has been determined with radioactive metal compounds ((191)Pt, with a half-life of approximately 3 days) by the simple chemical procedure of Roberts et al. In the filamentous cells, the platinum metal is associated with metabolic intermediates, nucleic acids, and cytoplasmic proteins; whereas, in inhibited cells, the platinum is combined only with the cytoplasmic protein. Similar experiments with gram-positive cells of Bacillus cereus and Staphyloccus aureus, which show no filamentous growth in the presence of cis-Pt(NH(3))(2)Cl(4), reveal that the metal complex does penetrate the cell wall and subsequently becomes bound predominantly by metabolic intermediates.