Abstract
HM 2 phage (group I) of Clostridium saccharoperbutylacetonicum was studied with regard to its peculiar behavior on exposure to deoxyribonuclease (DNase). It ss as inactivated by DNase: 10, 50 and 100μg/ml of DNase inactivated 20, 50 and 70% of free HM 2 phages, respectively. Whereas, JIM 3 phage (group II) was not affected by even 300μg/ml of DNase.
The mechanism of the inactivation of HM 2 phage by DNase was supposed either to be the enzymatic digestion of phage DNA by DNase, or to be a polyelectrolytic interaction between the phage protein and DNase. On these subjects, the following results were obtained. (1) Heat-treated DNase, the enzymatic activity of which was destroyed, did not affect on HM 2 phage. (2) HM 2 phage was inactivated by basic proteins which caused polyelectrolytic interaction with phage. Whereas, HM 3 phage, which was not inactivated by DNase, was inactivated more intensively than the former by basic proteins. (3) HM 2 phages in high concentration formed large aggregates with basic proteins, but not with DNase. (4) When EM 2 phages were exposed to DNase, the large amount of phage-DNA was released from phage coat membranes. These DNA were considered to be digested by DNase in phage particles.
These results indicated that the inactivation of HM 2 phage by DNase was due to the enzymatic action of DNase.
