Localization of acid phosphatases in the cell fractions of chick liver

3 molecular forms (P1, P2 and P3) of acid phosphatase (E.C.3.1.3.2) have been detected in chicken liver homogenate. The different intracellular localization of these molecules has been demonstrated by cellular fractionation and electrophoretic analysis. P1 and P2 phosphatases are both present in the particulate fraction. P3 is present in a pure form in the soluble fraction. The difference between the enzyme molecules present in the particulate fraction and that in the soluble one is confirmed by the different activation-inhibition effect of various ions and substances on the enzymatic activity of subcellular fractions.