Studies on sulphatases. 20. Enzymic cleavage of aryl hydrogen sulphates in the presence of H218O

Abstract

The hydrolysis of aryl hydrogen sulfates by acid, alkali and enzymes was carried out in H2O18, followed by isolation of the liberated sulfate and determination of its O18 activity. Hydrolysis of monopotassium p-nitrophenyl sulfate and dipotassium 2-hydroxy-5-nitrophenyl sulfate by human-liver arylsulfatase A, rat-liver arylsulfatase C, the aryl-sulfatase of Alcaligenes metalcaligenes and by acid resulted in cleavage of the O-S bonds. Only 2/3 of the theoretical amount of O18 for O-S cleavage was found in the barium sulfate isolated after alkaline hydrolysis of monopotassium p-nitrophenyl sulfate.