EN
Nuclear protein phosphatases activity of normal liver and hamster Kirkman-Robbins hepatoma cells was measured using 32P-phosphohistone and p-nitrophenylphosphate as substrates. Protein phosphatases activity toward both substrates was mainly located in the insoluble compartment of the nucleus - subfraction extracted with 2.0 M NaCl (HS) and nuclear matrix. Protein phosphatases of these subfractions exhibited different; susceptibility pattern to inhibitors used - okadaic acid, microcystin-LR and calyculin A. On the basis of these properties it can be suggested that nuclear matrix contains predominantly type - 2A protein phosphatase and HS subfraction type - 1 phosphatase.