Lysis and Lysis Inhibition with Escherichia coli Bacteriophage

The protein coats or ghosts of coli phage T2. II. The biological functions

Phage coats or ghosts, composed entirely of protein, appear to be responsible for protecting the phage nucleic acid from degradation by factors in the surrounding medium; attachment of the virus to its susceptible host; and delivering the nucleic acid to the interior of the cell. In addition, the ghosts have a number of biological actions which resemble similar actions of the parent phage. Thus, they both "kill" cells, inhibit pentosenucleic acid formation, interfere with subsequent infection by other virus particles, block adaptive enzyme formation, induce or trigger lysis of the host, and cause a leakage of phosphorus-containing fragments from the cell. Results to date fail to demonstrate a direct involvement of the ghosts in the passage of genetic information to the progeny. Several of the above changes induced in the host cell following attachment of ghosts could be derived from an alteration in but a single metabolic reaction. The stoichiometry of the ghost-bacterial cell interaction is different from that of the parent phage. Experiments to distinguish between a variable response of the host cell to reaction at different sites and a state of heterogeneity in the ghost preparations suggest the former but they are not decisive.

The protein coats or ghosts of coliphage T2. I. Preparation, assay, and some chemical properties

A method of preparing the protein coats or ghosts of phage T2 is described along with proof that the lytic action is a property of the ghost. An assay based on the lytic action toward host cells has been developed which permits a rapid evaluation of the number of ghosts with a reliability of +/-15 per cent. The antigenic and certain physicochemical properties of the ghost have been determined.

Alterations of plaque morphology in some coliphages

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