Sulphate Sulphatases

Purification of the arylsulphatase from the liver of a marine gastropod, Charonia lampas, failed to remove the associated L-ascorbic acid 2-sulphate sulphatase activity. The effects of various compounds on the arylsulphatase activity have been investigated.  

An assay for cerebroside sulphatase is based on t.l.c. and the use of tritium-labelled cerebroside sulphate as a substrate. The cerebroside sulphatase activity of the arylsulphatase A in human liver and kidney was investigated using this assay. Kinetic and other evidence suggested that cerebroside sulphatase also possesses arylsulphatase activity, although both activities are manifest by the same active site. Pure human cerebroside sulphatase has been shown to require the presence of bile salts and to be stimulated by manganese chloride. Cerebroside sulphatases isolated from a number of invertebrates are composed of multiple forms that were separated by isoelectric focusing. These enzymes have activities comparable to those from vertebrates, and they also exhibit arylsulphatase activity. Kinetic data (pH optima and Km values etc.) were reported for the enzymes, which were inhibited by nitrocatechol sulphate. 

Chondroitin 4-Sulphate Sulphatases.—The chondroitin 4-sulphate sulphatase from Proteus vulgaris preferentially attacked the sulphate group at 0-4 of the reducing 2-acetamido-2-deoxy-D-galactopyranosyl residues in the tetrasaccharides (10)— (13). The sulphate groups at 0-4 of the internal 2-acetamido-2-deoxy-D-galactopyranosyl residues in the tetrasaccharides (12) and (13) were also hydrolysed, but much more slowly. 

Chondroitin 4-sulphate sulphatase activity has been detected in mucosal scrapings from rats stomachs.  

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Hunter s syndrome (type II) Initially, this disease was erroneously classified as type I-H. Its nosological independence and X-chromosomal recessive transmission were recognized in 1964 (A. Nja). The disease is based on a deficiency of L-iduron-sulphate sulphatase and sulphoiduronate sulphatase. The syndrome may appear in a moderate or severe form. 

Acetamido-2-deoxy-D-galactose 6-sulphate sulphatase activity has been identified in rat skin (see p. 533). ... 

Glycolipid Sulphate Sulphatases.—Proteins of low molecular weight from secondary lysosomes activated a number of sphingolipid hydrolases, including cerebroside sulphatase (E.C. 3.1.6.8). ... 

Chapter 9. A substrate used in the assay of L-iduronic acid 2-sulphate sulphatase was obtained from sodium heparinate by methanolysis followed by nitrosation. Disaccharide monosulphates presumed to contain D-(methyl a-L-idopyranosiduronate-2-sulphate)-(l 4)-2,5-anhydro-D-mannose were isolated by gel filtration. Brucine L-guluronate and o-mannuronate, on the other hand, were obtained by treatment with brucine of the barium salts of the acids formed on hydrolysis of alginic add. ... 

The enzymic defect of Morquio s disease is attributed to the absence of 2-acetamido-2-deoxy-D-galactose 6-sulphate sulphatase. Extracts of fibroblasts from patients with the disease exhibit normal levels of 2-acetamido-2-deoxy-D-glucose 6-sulphate sulphatose and thus remove sulphate from 2-acetamido-2-deoxy-D-glucose 6-sulphate residues at the non-reducing ends of keratan sulphate. 

Sodium heparinate has been treated sequentially with methanolic hydrogen chloride and nitrous acid to produce 0-(methyl a-L-idopyranosyluronate 2-sulphate-(l -> 4)-2,5-anhydro-D-mannose. This disaccharide can be used for direct measurement of L-iduronic acid 2-sulphate sulphatase, an enzyme which is defective in Hunter s syndrome (mucopolysaccharidosis II). 

Glycopeptide-linkage hydrolases a-L-Guluronan lyase Heparin hydrolase Hyaluronate lyase Hyaluronidase L-Iduronic acid 2-sulphate sulphatase a-L-Iduronidase Inulinase Isoamylase Isopullulanase a-Lactalbumin Lactose synthase... 

Extracts of Actinobacillus and Pseudomonas species each catalysed extensive hydrolysis of corneal keratan sulphate, due to the combined actions of a 2-acetamido-2-deoxy-D-glucose 6-sulphate sulphatase, an exo-D-galactanase, an exro-jS-D-acetamidodeoxyglucanase, and an unidentified e/idb-glycosidase. ... 

Acetamido-2-deoxy-i>-galactose 4-Sulphate Sulphatases.—Extracts of skin fibroblasts obtained from patients with Maroteaux-Lamy syndrome exhibited a marked reduction in 2-acetamido-2-deoxy-D-galactose 4-sulphate sulphatase activity towards chondroitin 4-[ S]sulphate and a heptasaccharide derived therefrom. ... 

A purified 2-acetamido-2-deoxy-D-galactose 4-sulphate sulphatase from human placenta has been shown to be identical with an arylsulphatase B from the same source. The levels of the two enzymes were compared in cases of Maroteaux-Lamy syndrome. UDP-2-Acetamido-2-deoxy-D-galactose 4-sulphate is the natural substrate for the former sulphatase. 

L-Ascorbic Acid 2-Sulphate Sulphatases.—L-Ascorbic acid 2-sulphate served as a substrate for the arylsulphatase from bovine liver, and it was concluded that arylsulphatase and L-ascorbic acid 2-sulphate sulphatase activities are manifest by the same molecule. A similar conclusion was reached in an investigation of the enzymes in the liver of a marine gastropod, Charonia lampas. L-Ascorbic acid 2-sulphate sulphatase was inhibited by ADP and related compounds. ... 

Chondroitin 6-Sulphate Sulphatases.— A chondroitin 6-sulphate sulphatase from Proteus vulgaris did not hydrolyse the 6-sulphate groups of the tetrasaccharides (10), (11), and (14). ... 

Mucosal scrapings from rats stomachs contain chondroitin 6-sulphate sulphatase. ... 

L-Iduronic Acid 2-Sulphate Sulphatases.—2,5-Anhydro-4-0-(a-L-idopyranuronosyl 2-sulphate)-D-[l- H]mannitol 6-sulphate has been recommended as a substrate for the measurement of L-iduronic acid 2-sulphate sulphatase activity, since it furnishes a radioactive monosulphate that is readily separated by paper chromatography or electrophoresis. The enzymic reaction followed Michaelis-Menten kinetics 3 mmol 1 ) and was strongly inhibited by phosphate ions. 

Lactose Sulphate Sulphatases.— A deficiency of lactose sulphate sulphatase has been demonstrated in cases of metachromatic leukodystrophy (sulphatidosis). The enzyme also hydrolysed D-galactosyl sulphatide. 

The screening of heterozygotes for Hurler s syndrome is now possible, since the specific activity of the leucocyte-derived a-L-iduronidase in carriers is reduced by roughly 50%. The molecular size of dermatan sulphate excreted in the urine of patients with Hurler s syndrome can be monitored by gel-filtration chromatography on Sephadex G-75. The in vitro correction of the defect in Hurler s fibroblasts with bovine testicular hyaluronidase has produced encouraging results, and such treatment is also effective with Hunter s cells. A sulphated tetrasaccharide, which was obtained on digestion of chondroitin 6-sulphate with testicular hyaluronidase, has been used as the substrate in the determination of 2-acetamido-2-deoxy-D-galactose 6-sulphate sulphatase, an enzyme that is absent in patients with Morquio s disease. ... 

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