Abstract
The inactivation of bacteriophage ϕX174 by d-fructose 6-phosphate was investigated. This inactivation was inhibited by EDTA or reducing agents, and stimulated by Cu2+ but other metal ions could not be substituted for Cu2+. The reaction was also inhibited by superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6) and various free radical scavengers.
No detectable changes were observed in adsorption capacity of phage and in the conformation of the virion. The viral DNA in the virion was, however, found to be cleaved. This strand scission was also enhanced by Cu2+ and protected by catalase. Similar results were obtained when ϕX174 DNA was directly treated with d-fructose 6-phosphate.
It is concluded that the inactivation of ϕX174 is due to DNA strand scission in the virion by the free radical of d-fructose 6-phosphate or oxygen radicals generated during autoxidation of d-fructose 6-phosphate.