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Enzyme
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Query: EC:3.1.6.12 (
chondroitinase
)
2,183
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Pure human arylsulfatase A (EC 3.1.6.1) was found to hydrolyze ascorbic acid 2-sulfate to ascorbic acid and inorganic sulfate at rates from 200 to 2000 mumol/mg per h depending on the method of assay. This rate was lower than that observed with the synthetic substrate 4-nitrocatechol sulfate, but higher than that seen with the physiological substrate cerebroside sulfate. Extracts of cultured fibroblasts from normal subjects were also shown to hydrolyze ascorbic acid 2-sulfate; extracts of fibroblasts from patients with
metachromatic leukodystrophy
, known to be deficient in arylsulfatase A, did not. Similarly, hydrolysis of ascorbic acid 2-sulfate was not observed when a partially purified preparation of human
arylsulfatase B
was tested under a variety of conditions. Thus, in the human, arylsulfatase A appears to be the major, if not the only, ascorbic acid-2-sulfate sulfohydrolase.
...
PMID:Ascorbic acid-2-sulfate sulfhohydrolase activity of human arylsulfatase A. 0 34
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.
...
PMID:Arylsulfatases A and B in metachromatic leukodystrophy and Maroteaux-Lamy syndrome: studies with 4-methylumelliferyl sulfate. 0 5
Fibroblasts of four patients affected with mucosulfatidosis (multiple sulfatase deficiency, Austin variant of
metachromatic leukodystrophy
) were assayed for activities of the five sulfatases known to degrade mucopolysaccharides. These were iduronide 2-sulfate sulfatase, sulfamidase, N-acetyl-galactosamine 6-sulfate sulfatase,
arylsulfatase B
(N-acetylgalactosamine 4-sulfate sulfatase), and N-acetylglucosamine 6-sulfate sulfatase. The activities of these five sulfatases were severely depressed, thus confirming the known deficiency of
arylsulfatase B
and the absence of the Hunter and Sanfilippo III A corrective factors that have iduronide 2-sulfate sulfatase and sulfamidase activity, respectively. Together with earlier reports of the deficiencies of arylsulfatases A and C, cholesteryl sulfatase, and dehydroepiandrosterone sulfatae, mucosulfatidosis is now characterized by the deficiency of nine different sulfatases.
...
PMID:Multiple deficiency of mucopolysaccharide sulfatases in mucosulfatidosis. 52 91
The enzyme activity of arylsulfatase A and
arylsulfatase B
was studied in Epstein-Barr virus-transformed lymphoid cell lines established from control individuals and patients affected with
metachromatic leukodystrophy
, mucopolysaccharidosis type VI (or Maroteaux-Lamy syndrome) and multiple sulfatase deficiency. Lymphoid cells derived from patients with
metachromatic leukodystrophy
showed a severe deficiency in cerebroside sulfatase activity, as measured using radiolabelled sulfatide, but some residual activity of arylsulfatase A when measured with the chromogenic substrate, para-nitrocatechol sulfate. Lymphoid cells from mucopolysaccharidosis type VI had virtually no
arylsulfatase B
activity. In cells from patients with multiple sulfatase deficiency, the activities of lysosomal sulfatases as well as steroid sulfatase were deficient. Study of the molecular forms of arylsulfatases confirmed the complete deficiency of arylsulfatase A and
arylsulfatase B
activities in
metachromatic leukodystrophy
and mucopolysaccharidosis type VI lymphoid cells, respectively. The arylsulfatase A defect in metachromatic leukodys-lymphoid cells, respectively. The arylsulfatase A defect in
metachromatic leukodystrophy
cells could be demonstrated on focused fractions even using the artificial substrates, para-nitrocatechol sulfate and 4-methylumbelliferyl sulfate. To investigate the discrepancy of the arylsulfatase A activity data observed between whole cell homogenates and focused fractions when using the synthetic substrates, assays were tentatively performed for optimizing the determination of arylsulfatase A on crude homogenates of lymphoid cells. Although this work has indicated methodological limitations of the enzymatic assay of arylsulfatase A in lymphoid cells using methylumbelliferyl sulfate, it emphasizes the validity of lymphoid cell lines as an experimental model for the study of inborn deficiencies of arylsulfatases A and B.
...
PMID:Arylsulfatases A and B in EBV-transformed lymphoid cell lines: studies on their molecular forms in cells from patients with inborn sulfatase deficiencies. Comparative diagnostic value of enzymatic assays. 168 73
Two fluorescent derivatives of cerebroside sulfate ('sulfatide') have been synthesized and used as substrates for determining arylsulfatase A activity. These were 12-(1-pyrene)dodecanoyl cerebroside sulfate (P12-sulfatide) and 12(1-pyrenesulfonylamido)dodecanoyl cerebroside sulfate (PSA12-sulfatide). When incubated at pH 5.0 in the presence of 5 mM MnCl2 and 5.5 mM of taurodeoxycholate, either substrate was hydrolyzed by arylsulfatase A of human leukocytes. The rate of hydrolysis was proportional to the incubation time and concentration of enzyme; Michaelis-Menten type kinetics were observed with increasing concentrations of substrate. For determining the rate of hydrolysis, each of the two products (i.e., P12- and PSA12-cerebrosides) were separated from the bulk of respective unreacted sulfatide on small columns of DEAE-Sephadex A-25 and their fluorescence intensities read at 343-378 and 350-380 nm for the excitation and emission wavelengths for P12- and PSA12-cerebrosides, respectively. When extracts of skin fibroblasts derived from normal individuals and patients with Maroteaux-Lamy (lacking
arylsulfatase B
) or
metachromatic leukodystrophy
(lacking arylsulfatase A) were used as source of enzyme, P12-sulfatide was hydrolyzed by the former two but not by the latter cell extract. Several derivatives of cerebroside sulfate were also synthesized and found to inhibit the hydrolysis of pyrenesulfatide by leukocyte arylsulfatase A. The results demonstrate that these two pyrene containing sulfatides can be effectively used as specific substrates for the determination of arylsulfatase A activity in extract of cells and most probably also of tissues.
...
PMID:Synthesis of pyrene derivatives of cerebroside sulfate and their use for determining arylsulfatase A activity. 256 82
Arylsulfatase A hydrolyzes the artificial chromogenic substrate 4-nitrocatechol-sulfate at 0 degree C at a rate of 24% of that at 37 degrees C whereas
arylsulfatase B
is almost inactive at 0 degree C. Based on this observation, a simple assay was developed which permits the accurate determination of low residual arylsulfatase A activities in cultured skin fibroblasts of infantile, juvenile and adult
MLD
patients and pseudodeficient individuals. In cultured skin fibroblasts, the following residual activities were found with this assay system: late-infantile patients, 0.0%, one juvenile patient, 1.0%, adult patients, 4.4-14% of normal average. healthy pseudodeficient probands ranged between 18% and 32%.
...
PMID:A simple chromogenic assay for arylsulfatase A. 288 12
Fibroblasts cultured from the skin of a patient with
metachromatic leukodystrophy
have been found to manifest the biochemical defect of this inborn error of metabolism, a deficiency of arylsulfatase A. Diseased cells had less than five per cent of normal arylsulfatase-A activity, while activities of other lysosomal enzymes-including
arylsulfatase B
, beta-galactosidase, beta-glucuronidase, and beta-N-acetylglucosaminidase-were comparable to those in control cells. The presence of dissociable inhibitors in extracts of the diseased cells was excluded by combination experiments. The deficiency of the enzyme in leukocytes was also confirmed and is comparable to that found in cultured fibroblasts. The finding that readily cultured fibroblasts from easily obtained skin biopsy specimens exhibit the enzymatic defect should prove valuable in the biochemical study of this disease.
...
PMID:Metachromatic leukodystrophy: arylsulfatase-A deficiency in skin fibroblast cultures. 525 10
Arylsulfatase A and B have been demonstrated in preparations of human leukocytes. The level of activity of arylsulfatase A is markedly decreased in the preparations from patients with
metachromatic leukodystrophy
. Acid phosphatase and
arylsulfatase B
activities were normal. The assay of arylsulfatase A in leukocyte preparations can be useful in the diagnosis of
metachromatic leukodystrophy
while obviating the difficulties of current methods.
...
PMID:Metachromatic leukodystrophy: diagnosis with samples of venous blood. 566 37
Umbilical cord blood (UCB) has received increasing attention as a source of unrelated hematopoietic stem cells for transplantation. Lysosomal diseases have been effectively treated and normal enzymatic activity has occurred subsequent to engraftment using UCB. The use of donor cells with normal amounts of enzyme, rather than those from carriers whose level may be 50% or less, is an obvious goal. The frequency of such heterozygotes varies from 1:10 to 1:140 or lower depending upon the disease at issue. We assayed the levels of lysosomal enzymes in normal UCB in random samples as well as those used for transplantation. We measured the following enzymatic activities: alpha-l-iduronidase (Hurler), galactocerebrosidase (globoid cell leuko- dystrophy) and arylsulfatase A (
metachromatic leukodystrophy
). For the latter, levels of activity in UCB are comparable to those found in adult blood. In the case of
arylsulfatase B
(Maroteaux-Lamy) a level lower than adult level was found. An informed choice by the transplanting physician based on the activity of the relevant enzyme in the UCB donor will provide a better opportunity for an improved prognosis for more complete correction of the recipient's primary disease. Bone Marrow Transplantation (2000) 25, 541-544.
...
PMID:Measurements from normal umbilical cord blood of four lysosomal enzymatic activities: alpha-L-iduronidase (Hurler), galactocerebrosidase (globoid cell leukodystrophy), arylsulfatase A (metachromatic leukodystrophy), arylsulfatase B (Maroteaux-Lamy). 1071 32
Multiple sulfatase deficiency (MSD, OMIM 272200) is an autosomal recessive leukodystrophy associated with the deficiency of several, in total seven, sulfatases. The disorder is clinically and biochemically variable. The clinical picture combines features of mucopolysaccharidosis and
metachromatic leukodystrophy
(
MLD
, OMIM 250100) in a variable spectrum. Here we report a 3-year old Iranian girl with an
MLD
-like presentation of MSD.
Arylsulfatase A deficiency
and sulfatide excretion were found. Differently from what was previously reported in the literature, this girl never showed abnormal mucopolysaccharide excretion in the urine. There were no additional visceral or skeletal signs. She was originally diagnosed as having
MLD
. Only when she developed ichthyosis were seven additional sulfatases measured. In leukocytes, arylsulfatase A, steroid sulfatase and N-acetylglucosamine-6 sulfatase were profoundly deficient, while iduronate-2 sulfatase and
arylsulfatase B
were moderately reduced. In fibroblasts, N-acetylglucosamine-6 sulfatase was deficient, while arylsulfatase A was moderately reduced. This case illustrates the possible pitfalls in the clinical and laboratory diagnosis of MSD.
...
PMID:Pitfalls in the diagnosis of multiple sulfatase deficiency. 1131
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