Inactivation of bacteriophages with cis-platinum(II) diamminedichloride

The ability of the cis-plantinum(II) diamminedichloride and its hydrolytic products to inactive DNA bacteriophages was examined on the models T2, T4, T4BO1, T3, and lambda. The inactivation of all bacteriophages under study increases gradually during the first 40-90 min of the action of neutral cis-Pt(II) and later passes into an exponential phase. The extent of the region of slower inactviation is larger for osmotically sensitive strains T2 and T4. Inactivation with the hydrolytic products for cis-Pt(II) proceeds exponentially starting from the very beginning and their inactivating effect is higher by 40-80 times than for a comparable concentration of the original complex. The extent of inactivation is not affected with the HCR marker of the host bacteria. The sensitivity to cis-Pt(II) is higher for bacteriophages with a head permeable to salts. An additional inactivation ("after-effect") was observed after dilution of the complex; it can be removed by adding S-aminoisothiuronium dihydrobromide (AET). The results obtained are in good accord with the assumption that inactivation is due to the hydrolytic products arising in the head of bacteriophage.