Acetamido-2-deoxy-2-galactose 6-Sulphate Sulphatases

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

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. 

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. 

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. ... 

A sulphatase, which liberates sulphate from UDP-2-acetamido-2-deoxy-D-galactose 6-sulphate (the nucleotide occurring in quail egg white at high concentration), has been isolated from quail oviduct.The tissue also contained sulphatase activities for UDP-2-acetamido-2-deoxy-D-galactose 4-sulphate and nitrocatechol sulphate but these activities were removed from the 6-sulphatase fraction during purification. The UDP-2-acetamido-2-deoxy-D-galactose 6-... 

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