The sulphatase of ox liver. 7. The intracellular distribution of sulphatases A and B

Abstract

Sulphatases A and B occur in the same proportions in both the mitochondrial and microsomal fractions of ox liver. Sulphatase A can be obtained from both fractions by extraction with water. Such extracts also contain traces of sulphatase B, which may originate from cell particles damaged during the isolation procedure. Sulphatase B cannot be extracted from the particles by water but can be obtained in solution by extraction with 0.15 [image]-potassium chloride, by treatment with butan-1-ol or exposure to a lowered pH. The properties of sulphatases A and B prepared as described above are identical with those of the corresponding enzymes obtained by fractional precipitation with acetone and ammonium sulphate. It is concluded that both sulphatases A and B occur in the lysosomes but are either differently localized within these particles, sulphatase A occurring in the sap and sulphatase B in the insoluble framework, or the lysosomes themselves are heterogeneous, some containing sulphatase A, some sulphatase B.