Dissociation of the lipid-containing bacteriophage PRD1: effects of heat, pH, and sodium dodecyl sulfate.

The double-stranded DNA bacteriophage PRD1 replicates in Escherichia coli and Salmonella typhimurium. It has an outer protein coat surrounding a membrane. The phage lipids are derived from the host, but the membrane proteins are of phage origin. In this investigation we studied the effects of heat, pH, and sodium dodecyl sulfate on the integrity of phage particles. Heat and high pH result in the release of the main coat protein, P3, as trimers, whereas treatment of phage particles with detergent results in the solubilization of the membrane. Our results enable a distinction to be made between the phage structural proteins that are embedded in the lipid bilayer and those that appear to be more loosely associated with the membrane.