Studies on sulphatases. 2. The assay of the arylsulphatase activity of rat tissues

Abstract

The optimum conditions for the arylsulfatase of rat liver homogenates were established using K p-acetylphenylsulfate as the substrate. In 0.5 [image] acetate the enzyme is optimally active at pH 7.2 and a substrate concn. of 0.007 [image] Arylsulfatase activity varied linearly with the concn. of the enzyme but declined after incubation with the substrate for periods longer than 1.25-1.5 hrs. Incubation of rat liver homogenates in 0.5 [image] acetate at pH 7.2 in the absence of substrate caused considerable decrease in enzyme activity. Fractionation of homogenates by centrifugation divided the enzyme between the supernatant and the residue but some loss of enzyme occurred. A survey of the arylsulfatase content of rat tissues showed the greatest concn. in the liver. Adrenals, kidney, heart, spleen, lung, testes, ovaries, brain, muscle and intestine had lesser amts., the values decreasing in the order given. The arylsulfatase actiivity of the liver of male rats is significantly higher than that of females.