Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.6.1 (sulfatase)
3,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sorting of newly synthesized mannose 6-phosphate (M6P)-containing proteins and of the major excreted protein (MEP), a lysosomal thiol proteinase, was studied in NIH-3T3 cells transfected with the cDNA of human insulin-like growth factor II (IGF II) or with the vector alone. Extracts from media and cells labelled with [35S] methionine were used for chromatography on a M6P/IGF II receptor affinity matrix or for immunoprecipitation to assess the distribution of newly synthesized M6P-containing proteins and MEP, respectively. The results indicate that the overexpression of IGF II did not affect the synthesis and the sorting of M6P-containing proteins and of MEP. The binding and uptake of the lysosomal enzyme arylsulfatase A were not affected in IGF II overexpressing cells.
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PMID:Insulin-like growth factor II overexpression does not affect sorting of lysosomal enzymes in NIH-3T3 cells. 167 27

N-[7-Nitrobenz-2-oxa-1,3-diazol-4-yl]psychosine sulfate (NBD-PS), a fluorescent analog of cerebroside sulfate (CS), was synthesized and tested as an alternative to the radiolabeled forms of CS used for assaying arylsulfatase A (ASA) in its physiological role as a cerebroside sulfate sulfohydrolase. NBD-PS simulates the natural substrate for ASA. Protocols have been developed for its use in differentiating low enzyme activities in diagnostic samples. Hydrolysis of NBD-PS is specific for ASA and optimal assay parameters were identical to those determined for CS. Differentiations between each of the major phenotypes for ASA activity were possible in the set of samples tested. One particular advantage was the ability to discriminate between individuals exhibiting arylsulfatase A pseudodeficiency and the truly deficient individuals with metachromatic leukodystrophy. Differential diagnosis was possible with fibroblast extracts by an assay that is more sensitive than procedures employing radioisotopes. Reaction products may be analyzed quantitatively by HPLC, or semiquantitatively with TLC. NBD-PS provides a simpler, safer, and more cost-effective means of performing natural substrate enzyme assays for ASA. Phenotyping with the fluorescence assay is an effective alternative to the laborious radioactive CS preparations and tissue culture loading studies that have previously been necessary.
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PMID:Synthesis and characterization of NBD-PS: a fluorescent analog of cerebroside arylsulfatase A deficiency disorders. 168 Mar 31

A sample of 140 children exhibiting neurologic disturbances (93 suffering from epilepsy and 47 with delayed psychomotor development or mental retardation) was tested for the activity of some lysosomal enzymes. A partial deficiency of arylsulfatase A (ASA) in leucocytes (activities lower than 60% of the control average) was detected in 36 patients (25.7%), whereas few ASA-deficient individuals (1.4%) were found in the control sample of 71 healthy children. Therefore, the frequency of ASA deficiency is abnormally high in our sample of pediatric patients. ASA activity levels were also assayed on fibroblasts from 12 of the 36 ASA-deficient patients; the mean activity in these cells was 20% of the control average. Excretion of urinary sulfatides was not increased in the tested ASA-deficient patients (10/36). Clinical symptoms of these ASA-deficient patients bore no resemblance to classical metachromatic leucodystrophy (MLD), but resemble literature cases labeled as atypical MLD or diagnostic puzzles. This result suggests that reduced ASA activity might be associated with an increased risk of developing neurologic or neuropsychiatric disturbances in children.
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PMID:Reduced activity of arylsulfatase A and predisposition to neurological disorders: analysis of 140 pediatric patients. 168 56

Fragments of the arylsulfatase A (ARSA) gene from a patient with juvenile-onset metachromatic leukodystrophy (MLD) were amplified by PCR and ligated into MP13 cloning vectors. Clones hybridizing with cDNA for human ARSA were selected, examined for appropriate size inserts, and used to prepare single-stranded phage DNA. Examination of the entire coding and most of the intronic sequence revealed two putative disease-related mutations. One, a point mutation in exon 3, resulted in the substitution of isoleucine by serine. Introduction of this alteration into the normal ARSA cDNA sequence resulted in a substantial decrease in ARSA activity on transient expression in cultured baby hamster kidney cells. About 5% of the control expression was observed, suggesting a small residual activity in the mutated ARSA. The second mutation, a G-to-A transition, occurred in the other allele and resulted in an altered splice-recognition sequence between exon 7 and the following intron. The mutation also resulted in the loss of a restriction site. Apparently normal levels of mRNA were generated from this allele, but no ARSA activity or immuno-cross-reactive material could be detected. A collection of DNA samples from known or suspected MLD patients, members of their families, and normal controls was screened for these mutations. Four additional individuals carrying each of the mutations were found among the nearly 100 MLD patients in the sample. Gene segregation in the original patient's family was consistent with available clinical and biochemical data. No individuals homozygous for either of these two mutations were identified. However, combinations with other MLD mutations suggest that the point mutation in exon 3 does result in some residual enzyme activity and is associated with late-onset forms of the disease. The splice-site mutation following exon 7 produces late-infantile MLD when combined with other enzyme-null mutations, implying that it is completely silent enzymatically.
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PMID:Two new arylsulfatase A (ARSA) mutations in a juvenile metachromatic leukodystrophy (MLD) patient. 168 88

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.
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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

Pseudodeficiency is defined as the in vitro measurement of low activity (usually under 15% of the normal mean for controls) of an enzyme in a healthy person. They may be hard to distinguish from presymptomatic people who will present with adult-onset clinical disease. The finding of healthy people with low arylsulfatase A and galactocerebrosidase activities is well documented. This confuses the laboratory doing testing and the clinician providing the sample. Therefore confirmation of a diagnosis of metachromatic leukodystrophy and Krabbe disease, as well as accurate identification of carriers, requires additional testing including 14C-sulfatide loading in cultured skin fibroblasts, examination of urine for excretion of undegraded lipids, examination of enzyme levels in additional family members including grandparents, and molecular analysis of DNA samples for known mutations.
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PMID:Pseudodeficiencies of arylsulfatase A and galactocerebrosidase activities. 168 77

Metachromatic leukodystrophy (MLD) is a lysosomal storage disease caused by the deficiency of arylsulfatase A (ASA). The ASA cDNA as well as the gene has been cloned. The gene is about 3 kb long and consists of 8 exons. The two most frequent alleles causing MLD have been characterized and the distribution of these alleles among patients with different clinical forms of MLD has revealed a simple genotype-phenotype correlation. Some individuals have low ASA activities but are healthy. This condition has been called ASA pseudodeficiency. These individuals are homozygous for the ASA pseudodeficiency allele which only encodes 5-10% of the ASA activity compared to the normal allele. The mutations in the PD allele have been characterized. Based on the knowledge of these mutations diagnostic assays have been developed to differentiate ASA deficiencies associated with PD or MLD.
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PMID:Molecular genetics of metachromatic leukodystrophy. 168 78

Arylsulfatase A was radioimmunoassayed in serum specimens of 96 healthy volunteers and 368 patients with histopathologically confirmed cancer of gastrointestinal tract, breast, lung, central nervous system, kidney and woman genital tract. Sensitivity, specificity and predictive value of the test were 43%, 82% and 90%, respectively, which means that a positive test is significant for diagnosis of cancer regardless of its localization. More detailed statistical analysis of the results indicates that determination of the serum concentration of arylsulfatase A might be helpful in the diagnosis of lung (59% sensitivity, 82% specificity) and central nervous system cancer (60% sensitivity, 82% specificity). Further studies should also be continued in respect to renal and women genital tract cancers for which the results of the test, although promising, are at present not conclusive due to the small numbers of examined cases. Particularly, determination of serum arylsulfatase A in case of endometrial cancer seems to be of diagnostic value. Arylsulfatase A concentration in serum with a lower than 40% sensitivity of the test cannot be considered as a valuable tumor indicator in the case of cancer of breast and gastrointestinal tract, although 80% predictive value of the test for the latter group of tumors is quite high and perhaps merits additional consideration.
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PMID:Arylsulfatase A in serum from patients with cancer of various organs. 168 88

Arylsulfatase A was isolated from urine and human liver. The enzyme was homogeneous with respect to charge and had high specific activity--64 U/mg and 34 U/mg for arylsulfatase A from urine and liver respectively. The enzyme from urine as well as the liver one contained two nonidentical subunits with molecular weights varying about 5 kDa. Treatment of the enzyme from urine, liver and from placenta with endo-beta-N-acetylglucosaminidase F did not remove all carbohydrate from any subunit even in denaturing conditions. Deglycosylation of the enzyme with this one and other glycosidases under various conditions resulted in a decrease in the apparent molecular weights of subunits only by 1-2 kDa. The difference between molecular weights of subunits did not change upon deglycosylation of arylsulfatase A. The results suggest that the presence of two nonidentical subunits is due to presence of different polypeptides rather than various glycosylation of a single polypeptide chain. Arylsulfatase A from urine was inactivated following reaction with diethyl pyrocarbonate at pH 5.5 or at pH 7.0. This confirmed the presence of histidine essential for its catalytic activity. It was also shown that the enzyme was inactivated with ferrate ion, structural analogue of orthophosphate and strong oxidizing agent. The conditions of inhibition of arylsulfatase A carried out with the use of ferrate as well as catalytic and immunochemical properties of the modified enzyme suggest that ferrate reacted with the active site of arylsulfatase A. The results allow to expect that a reactive histidine is present in enzyme's active site and that this aminoacid is modified with ferrate. A simple, sensitive and specific radioimmunoassay was developed for the determination of arylsulfatase A in human serum and urine. The method allows to measure less than nanogram amounts of the enzyme in human body fluids. The test was used to determine arylsulfatase A in serum specimens of 368 patients with histopathologically confirmed cancer of gastrointestinal tract, breast, lung, central nervous system, kidney and woman genital tract. The highest mean concentration of arylsulfatase A in serum and significantly higher than that in the control group of 96 healthy blood donors was found in the case of groups of lung, kidney and central nervous system cancer. The results indicate that the radioimmunoassay determination of serum level of arylsulfatase A might be helpful in diagnosis of lung and central nervous system cancer. Arylsulfatase A serum level cannot be treated as a valuable indicator in the case of cancer of breast and gastrointestinal tract.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Arylsulfatase A--physico-chemical properties and the use of enzyme radioimmunoassay in medical diagnosis]. 168 65

The lysosomal catabolism of sulfatide requires arylsulfatase A and a specific sphingolipid activator protein, SAP-1. While most patients with metachromatic leukodystrophy have mutations in the gene for arylsulfatase A, some patients have deficient SAP-1, as determined by immunological techniques. We now describe the molecular findings in a patient who died at 22 years of age with SAP-1 deficiency. The DNA polymerase chain reaction was used to amplify regions of cDNA which were subcloned in M13 phage DNA and sequenced by the dideoxy chain-termination method. The patient was found to have a 33-base-pair insertion between nucleotides 777 and 778 (numbered from the A of the ATG initiation codon). No other changes were found in the coding sequence of the cDNA from this patient. At the site of the insertion some normal people have an additional 9 base pairs, which correspond to the last 9 nucleotides at the 3' end of the insertion. The cDNAs from the second-cousin parents were amplified and sequenced, and in both two alleles were identified, one with the 33-base-pair insertion and one with no insertion. Two brothers were found to have only the normal alleles and a sister was found to have the 33-base-pair insertion and a normal allele. The findings confirm studies performed on leukocyte extracts demonstrating normal antigen levels in the two brothers and a lower level in the sister. The presence of 11 additional amino acids in the coding region of mature SAP-1 in this patient causes significant changes in the hydropathy profile compatible with the previous findings at the protein level.
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PMID:Insertion in the mRNA of a metachromatic leukodystrophy patient with sphingolipid activator protein-1 deficiency. 168 85


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