Studies on the Arylsulphatase and phenol sulphotransferase activities of Aspergillus oryzae

Abstract

1. Crude extracts of Aspergillus oryzae grown under conditions of sulphur limitation possess high arylsulphatase activity. 2. This activity can be greatly enhanced by the inclusion of tyramine or a number of other phenols in the assay medium. 3. The arylsulphatase activity of these extracts can be resolved into three distinct fractions by chromatography on DEAE-cellulose. 4. The effect of tyramine is restricted to one of these fractions only. 5. Evidence is presented which indicates that this effect is the consequence of a phenol sulphotransferase activity, which shows no requirement for 3'-phosphoadenosine 5'-phosphate as a cofactor, and which will not transfer sulphate from 3'-phosphoadenosine 5'-sulphatophosphate to potential phenolic acceptors. 6. The three enzymes differ also in their molecular weights and substrate specificities.