Rat liver DNase I-like activity and its interaction with actin.

Monomeric G actin, total actin and the F:G actin ratio were determined in the rat liver cytosol and nucleoplasm by measuring the inhibition of standard crystalline DNase I. Actin was purified from rat liver nucleoplasm by Sephadex filtration. Accompanying the considerable amount of actin an endogenous DNase I like activity was found in rat liver cytosol and nucleoplasm. It was shown, that similarly to DNase I from bovine pancreas the liver DNase was inhibited by mammalian and avian skeletal muscle actin as well as by endogenous liver actin, as verified by electrophoresis of DNase containing extracts on polyacrylamide gels with incorporated DNA.