Studies on sulphatases. 12. The arylsulphatases of human tissues

Abstract

I956 the mixing chamber before the reagents are emptied into the reaction vessel. The accuracy of mixing exceeds the limit of resolution of the spectrophotometer. 3. The reaction vessel consists of a cylindrical quartz tube held in position with unstretched nylon bushings in a brass block adjacent to the cuvette housing unit. The flow of material is controlled by a needle valve at the exit of the reaction-vessel housing unit. Approximately 6 ml. of fluid is required to flush out the reaction vessel. 4. Temperature control is maintained with a water jacket round the four syringes and with cooling channels within the reaction-vessel housing unit. Steady-state temperature is reached in the syringes in a maximum of 6 min. 5. The signal from the density-scale slide-wire potentiometer of the spectrophotometer is fed through a potential divider into a Brown stripchart recorder. As the operator tracks the changes in optical density of the reaction mixture the percentage transmission is recorded continuously. By means of a mixing switch the temperature of the reaction vessel measured with a thermopile is recorded at intervals during the reaction time. 6. The percentage error (standard deviation) of the velocity constant of decomposition of hydrogen peroxide by bacterial catalase measured with this apparatus is less than ± 2 %.

Purification and properties of arylsulphatase A from rabbit testis

“…Those enzymes were partially purified from spermatozoa acrosomes (Yang & Srivastava, 1974a) and from testis (Yamato et a!., 1974;Yang & Srivastava, 1975a). Several mammalian tissues contain at least two or three distinct enzymes (arylsulphatases A, B and C) capable of hydrolysing arylsulphate ester linkages (Dodgson et a!., 1956). Arylsulphatases A and B can be distinguished by their different pH optima, substrate affinities, anomalous kinetics and electrophoretic mobilities (Farooqui & Bachhawat, 1972).…”

The Arylsulphatases and Related Enzymes in the Livers of Some Lower Vertebrates

“…That those enzymes were type I arylsulphatases, similar in many ways to those of the eutherian mammals, was shown by their microsomal origin, their insolubility and their ready hydrolysis of nitrophenyl sulphate. The enzyme from the opossum, however, differed from the known type I arylsulphatases of animal origin by its powerful inhibition by phosphate ions and, to a lesser extent, by sulphate ions, both of which are without significant effect on the type I arylsulphatases of the ox and the rat (Roy, 1956b) and of man (Dodgson, Spencer and Wynn, 1956). It should be recalled, however, that the otherwise typical type I arylsulphatase of Aerobacter aerogenes is inhibited by phosphate (Harada and Kono, 1954).…”

“…Sulphatases B do not show these anomalies (Roy, 1954;Dodgson and Wynn, 1958). They, on the other hand, hydrolyse nitrophenyl sulphate only extremely slowly in the absence of chloride ions (Roy, 1954) although they readily hydrolyse this substrate when these ions are present Morrow, 1959, 1960;Roy, 1960a).…”

Studies on metabolism of vitamin A. 2. Enzymic synthesis and hydrolysis of phenolic sulphates in vitamin-A-deficient rats

“…Existing literature shows that the relative distribution of the arylsulphatases A, B and C was studied with whole homogenates or with acetonedried preparations of animal tissues (Robinson, Smith & Williams, 1951;Dodgson et al 1955;Dodgson, Spencer & Wynn, 1956;Pulkinen, 1961). A reinvestigation of their distribution in rat tissues, the mitochondrial fraction being used for the sulphatases A and B and the microsomal fraction for sulphatase C, instead of the whole homogenates, was therefore undertaken ( Table 2).…”