Inactivation of bacteriophage with polyanions, and the role of amines in activity.

The forces which initiate and orient the attachment of bacteriophage to the receptor cell are unknown. It is possible that electrostatic forces participate in this process (l-5). It has remained of interest to study the influence of strongly negatively charged polyelectrolytes on the early stages of phage-bacterial cell interaction, especially since the receptor cell surface is also negatively charged. It was our hope that we might block normal attachment and inhibit the viability of the bacteriophage, just as enzymes can be inhibited with a polyelectrolyte more strongly charged than their substrate (6). In the experiments reported below, the phages were incubated with low concentrations of polyanions in aqueous suspension before the mixture was diluted out and plated in normal medium. In this manner the effect of the negative macromolecules was restricted to the phage. We have found that if the incubation was carried out at a somewhat reduced pH, the viability of the bacteriophage was irreversibly lost. In contrast, no irreversible loss of viability of the bacteriophage occurred after similar incubation with low molecular weight anions. We presented a preliminary report on this polyanionic inactivation of T2 bacteriophage (7). Upon further investigation we found that the attachment was not reduced substantially when the viability was irreversibly lost after the polyanion treatment, but that the cationic amines, putrescine and spermidine, which are present in the phage and neutralize the deoxyribonucleic acid (8), had been released.