Purification and properties of arylsulphatase B of human liver.

1. A purification scheme for an arylsulphatase B from human liver is described. Specificity of purification was achieved by the use of the affinity chromatography on an agrose-4-hydroxy-2-nitrophenyl sulphate derivative. The scheme provides a rapid and convenient method for preparation of a highly purified enzyme. 2. The purified enzyme was examined by isoelectric focusing electrophoresis on polyacrylamide gel and by ultracentrifugation and was found to be catalytically homogenous, with an apparent molecular weight of 50000 and a specific activity of 93.3 units/mg of protein. 3. The kinetic properties of the purified preparation and the effect of various amino acid group-specific reagents on the catalysis of the enzyme are described. The involvement of histidine residues in the active site of the enzyme is suggested. 4. The purified enzyme lost activity rapidly on freezing. The implication of this observation is discussed in terms of a possible dissociation-reaggregation phenomenon induced by cold treatment.