Arylsulfatases A and B in metachromatic leukodystrophy and Maroteaux-Lamy syndrome: studies with 4-methylumelliferyl sulfate.
Metachromatic leukodystrophy and Maroteaux-Lamy syndrome can be diagnosed by assay of leukocyte or fibroblast arylsulfatase A and B activity with the fluorogenic substrate 4-methylumbelliferyl sulfate. The arylsulfatases are extracted into a 27000 x g supernatant by sonication in 0.9% sodium chloride and then separated with CM-32 on columns or in test tubes. In 0.05 M sodium acetate pH 6.0, arylsulfatase A is not absorbed while arylsulfatase B is retained by the resin. The arylsulfatase B is then eluted from the resin with 0.3 M sodium chloride. The arylsulfatase A activity obtained from normal leukocytes and fibroblasts is linear for the initial 10 minutes of the reaction, is stimulated 3-fold by 6 mM lead acetate and inhibited 80% by 0.24 mM silver nitrate. After separation with CM-32, the arylsulfatase B activity is stimulated 3-fold by Triton X-100 (0.1%). Arylsulfatase A but not arylsulfatase B is destroyed by heat (60 degrees). Both leukocyte and fibroblast arylsulfatase A activity was reduced to 11% of control values in metachromatic leukodystrophy. Essentially no arylsulfatase B activity was detected in cells from patients with Maroteaux-Lamy syndrome. Metachromatic leukodystrophy heterozygotes but not Maroteaux-Lamy syndrome heterozygotes can also be distinguished by this method. A heat inactivation technique utilizing the differential thermal stabilities of the two enzymes for diagnosis of patients with Marotezux-Lamy syndrome is also described. The advantages of these 4-methylumbelliferyl sulfate assay procedures over the p-nitrocatechol sulfate method of assay are greater sensitivity, selectivity for the desired enzyme and potential for use in large scale testing.
D001192:Arylsulfatases / Q000302:isolation & purification / Q000378:metabolism*; D002553:Cerebroside-Sulfatase / Q000378:metabolism; D002803:Chondro-4-Sulfatase / Q000378:metabolism; D004355:Drug Stability; D004588:Electrophoresis, Cellulose Acetate; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006923:Hymecromone / Q000031:analogs & derivatives; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D007962:Leukocytes / Q000201:enzymology; D007966:Leukodystrophy, Metachromatic / Q000175:diagnosis / Q000201:enzymology*; D008722:Methods; D009083:Mucopolysaccharidoses / Q000201:enzymology*; D009087:Mucopolysaccharidosis VI / Q000175:diagnosis / Q000201:enzymology*; D012867:Skin / Q000201:enzymology; D013429:Sulfatases / Q000378:metabolism*
D007527:Isoenzymes; D006923:Hymecromone; D013429:Sulfatases; D001192:Arylsulfatases; D002553:Cerebroside-Sulfatase; D002803:Chondro-4-Sulfatase