Comparative studies on nuclear and cytosol phosphohistone phosphatases of calf liver

1. 1. Calf liver cytosol and nuclear phosphohistone phosphatases have been resolved into multiple molecular weight forms by DEAE-cellulose column chromatography. 2. 2. Treatment of these enzymes with ethanol, converted these multiple forms into a single molecular species. 3. 3. Before ethanol treatment, the cytosol enzyme activity is stimulated several-fold by salt, divalent cations and ATP, but ethanol treatment abolished this response. 4. 4. The nuclear enzyme is rather unresponsive to these factors before and after the ethanol treatment. 5. 5. Both the nuclear and cytosol enzymes after ethanol treatment have similar molecular weights, isoelectric points and K_m values towards phosphohistone.