[Separate extraction of 2 fractions of Mn++-dependent poly-A polymerase activity in liver cell nuclei of rats].

Part of the Mn++-dependent poly(A) polymerase activity of rat liver nuclei leaks out of the organelles when they are suspended in isotonic sucrose. With 0.5 ml/g fresh tissue of medium or more no increase in enzyme leaking out occurs after 30 min. Three repeated isotonic suspensions yelded all the activity thus obtainable (about 25% of total). Increasing the ionic strength of the suspension medium causes dramatic inactivation of the residual activity both in the extracted fraction and in the remaining one. It is confirmed that the bound activity is attached to chromatin.