[Uracil-DNA-glycosylase in the rat: correlation between the enzyme activity and rate of DNA synthesis in different tissues].

Uracil-DNA-glycosylase which releases uracil residues from DNA has been purified from rat liver more than 300-fold. The enzyme has a molecular weight of about 28,0000, Km = 1.7 . 10(-9) M. The content of uracil-DNA-glycosylase in five different tissues of the rat is correlated with the rate of DNA synthesis in the tissues. The enzyme activity in rat liver increases more than 3 times after partial hepatectomy, showing a peak 28-32 hrs following the surgery. The results obtained suggest that uracil-DNA-glycosylase from mammalian cells releases uracil residues from DNA at time intervals close to those of replication.