Rapid purification of inositol monophosphate phosphatase from beef brain

A procedure is described for preparation of homogeneous inositol monophosphate phosphatase (EC 3.1.3.25) from beef brain in less than 2 days with an overall recovery of 15-25%. This enzyme, an essential part of the inositol phospholipid cycle in brain, is a proposed site of action of lithium ions in manic-depressive disorders. The major purification steps are: a) removal of most interfering protein by heat denaturation at 75 degrees C for 1 h, b) separation by anion exchange at a pH (6.0) near the enzyme's pI (4.9), and c) adsorption of most remaining impurities on a Procion Red affinity column.