Deoxyribonucleolytic activity of alpha- and beta-momorcharins

alpha- and beta-Momorcharins were purified by an improved procedure using the affinity Affi-gel Blue gel and the ion exchange Mono-S FPLC column. Both purified alpha- and beta-momorcharins possessed deoxyribonucleolytic activity. Under normal digestion conditions, they cleaved the supercoiled, double-stranded SV-40 DNA to produce nicked circular and linear DNAs. Prolonged incubation did not have any further effects. On the other hand, the linear DNAs, lambda, Ad-2 and T7 were not digested by alpha- nor beta-momorcharin. Thus, it appears that the conformation of the DNA may be the determining factor for the deoxyribonucleolytic activity of these momorcharins.