The dialysis of brain pyrophosphatase

Abstract

Aqueous homogenates of rat brain were made by homogenizing the whole brain in ice-cold 0.9% NaCl and diluting with water to approximately 10 mg/ml. Activity measurements were carried out at 37[degree] as previously described (Gordon, J.J. (1953) Biochem. Jour. 55: 812). Brain pyrophosphatase is readily inactivated on standing at 0[degree] in slightly acid solution. The fall in activity which takes place when the enzyme is dialysed is not observed when dialysis is carried out under conditions which prevent the pH from falling.