CHEMICAL ANALYSIS OF THE T7 BACTERIOPHAGE OF ESCHERICHIA COLI

Abstract

Chemical analyses have been made of several bacteriophages (l-9) in more or less purified preparations.However, only a few, the T:, (G-8) and, more recently, the Te (9) bacteriophages of Escherichia coli, have been studied in sufficient detail for comparison with analogous studies on plant and animal viruses.The results obtained on the bacteriophages thus far examined have shown that, while these agents are somewhat similar to the animal viruses in the constitution of their major components, the bacterial viruses differ, with few exceptions, from other viruses in the quantitative distribution of components, the difference being manifested principally in an exceedingly high content of nucleic acid in the bacterial viruses.Judging from phosphorus content and direct estimation, the content of nucleic acid has been uniformly high in the various bacteriophages (l-9), and it would appear that this property and certain others may be characteristic of these agents.Recently, studies (10) were undertaken on another bacteriophage, Tr of E. wli, which was chosen because of its apparently great difference from the Tz agent in size, morphology, and immunological properties (11).The Tr virus is spherical, has about 12 per cent of the mass of the T, (and TB) phage, has no tail, and is immunologically unrelated to either the Tz or Ta agents.The purification and some of the properties of the Tr bacteriophage were reported in a recent publication (10).The results of chemical analyses of the agent and a comparison with analogous findings with 'l's, Ts, and the host organism, E. coli (strain B), are described in the present paper. Materials and MethodsPurifiation-The T, bacteriophage and the host organism E. coli (strain B) were obtained from Dr. M. Delbtick.Cultivation of the agent for purification was carried out by the procedures already described (10).Most of the analyses were made on two different batches, A and B, prepared in the present work.Some estimations were made with the phage prepared in the previous experiments.