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)

Previous studies from this laboratory have demonstrated that arylsulfatase B (ASB) is phosphorylated by a protein kinase, which is the first finding of phosphorylation in lysosomal hydrolases. The present study was undertaken to characterize the sites of phosphorylation in ASB from transplanted human lung cancer and from normal human tissues, and to identify type of tumor protein kinase responsible for the phosphorylation of ASB. When ASB purified from liver and placenta was phosphorylated in vitro by a cAMP-dependent protein kinase, it gave a single tryptic phosphopeptide (X) and phosphothreonine. On the other hand, the tumor ASB which had been phosphorylated in vivo demonstrated two phosphopeptides X and Y. Since the tumor ASB had been shown to be phosphorylated both at threonine and serine residues, phosphorylation at threonine residue of peptide X, which is phosphorylated by a cAMP-dependent protein kinase, will be cancer-associated. Through photoaffinity labeling with a labeled cAMP analogue to detect regulatory subunits of cAMP-dependent protein kinase subtypes, it was found that the cAMP-dependent protein kinase in the transplanted lung tumor was largely type II which can be ascribed to the appearance of highly phosphorylated ASB in the tumor.
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PMID:Protein phosphorylation of human lysosomal arylsulfatase B from normal and cancer tissues. 338 98

Secreted and intracellular arylsulfatase B (ASB) activities were measured in normal and osteoarthritic (OA) human chondrocyte cultures in the absence and presence of monensin, ammonium chloride, and chloroquine. Of the three agents added, only monensin produced a significant stimulation of secreted enzyme activity. Osteoarthritic cells consistently exhibited a three-fold higher level of secreted specific ASB activity than did normal cells, with or without monensin. When compared with normal cells, OA cells also consistently exhibited a twofold heightened intracellular specific enzyme activity both in the absence or presence of monensin. With increasing dosage of monensin, secreted and intracellular ASB activity increased for both OA and normal cells. Total enzyme activity of secreted and intracellular ASB was found to be cell density dependent. No inhibition of secreted or intracellular ASB activity was observed for sparsely plated cultures. In contrast to sparse cultures, an inhibition of secreted ASB, with or without monensin, was observed in densely plated cultures. Intracellular total activity was not inhibited by high-density cultures. Secreted ASB activity was found to be time-dependent after passage. Enzyme activity was maximal at 6 h in both OA and normal cells and decreased by the end of 24 h both in serum-free medium and in serum-free medium with monensin. When compared with normal cells, OA cells expressed higher levels of ASB activity under all test conditions. This heightened activity therefore appears to be a property inherent in the OA chondrocyte.
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PMID:Monensin stimulation of arylsulfatase B activity in human chondrocytes. 373 35

The molecular pathology of the deficient arylsulfatase B activity in feline mucopolysaccharidosis (MPS) VI was investigated. Compared with the highly purified normal feline hepatic enzyme, the purified MPS VI residual activity had a 100-fold higher Michaelis constant (K(m)), an altered electrophoretic mobility, half the apparent native molecular weight, and markedly decreased thermo-, cryo-, and pH stabilities. Molecular weight and alkylation studies were consistent with the normal enzyme being a homodimer and the residual MPS VI enzyme a monomer. When incubated with various sulfhydryl reagents, the residual specific activity was enhanced several-fold, whereas the activity of the purified normal enzyme was un-affected or slightly inhibited. In the presence of dithiothreitol (DTT) and cysteamine, a lysosomotropic aminothiol, the residual activity had an electrophoretic mobility and native molecular weight similar to those of the normal feline enzyme. These findings suggested that the monomeric residual enzyme was dimerized in the presence of thiol-reducing agents. To determine if thiol-induced subunit association could therapeutically increase the residual activity and degrade the accumulated dermatan sulfate, in vitro and in vivo experiments were undertaken. When 2 mM DTT or cysteamine was incubated with heparinized whole blood from an MPS VI cat, the leukocyte residual arylsulfatase B activity increased 11- and 20-fold, respectively, and the accumulated dermatan sulfate was degraded in the presence of both thiol reagents. Intravenous administration of DTT (50 mg/kg) effected an immediate, but transient, increase in leukocyte residual activity; however, the substrate levels were not significantly decreased. In contrast, intravenous administration of cysteamine (15 mg/kg) increased leukocyte residual activity more than sixfold 30 min postinfusion; concomitantly, the leukocyte substrate was decreased to 35% of the initial level immediately after infusion and to about 45% of preinfusion values during the 120-min period studied. These results suggest that the defective residual activity in feline MPS VI can be therapeutically manipulated by thiol-induced subunit association. Furthermore, this animal analog provides a prototype for the investigation of human inborn errors of metabolism resulting from enzymatic defects that might be amenable to enzyme manipulation therapy.
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PMID:Enhancement of residual arylsulfatase B activity in feline mucopolysaccharidosis VI by thiol-induced subunit association. 679 47

Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI; MPS VI) is a disorder which results from a deficiency in the lysosomal associated enzyme N-acetylgalactosamine 4-sulfatase (4-sulfatase). A feline model of human MPS VI has previously been described and provides a system for the evaluation of enzyme replacement therapy protocols. As a preliminary study to human 4-sulfatase enzyme replacement therapy in feline we have compared the immunochemical properties of human and feline 4-sulfatase. By SDS-PAGE the molecular mass of purified feline and human 4-sulfatase were similar under both reducing and nonreducing conditions. There was, however, a detectable conformation difference between human and feline 4-sulfatase indicating some structural variation. Feline 4-sulfatase reacted weakly with a panel of monoclonal antibodies in an immunobinding assay (interacting with 4-sulfatase in free solution), but the same monoclonal antibodies reacted strongly with feline 4-sulfatase in an immunoquantification assay where the feline 4-sulfatase was bound to a polyclonal antibody (which presumably induces a conformation change in the feline 4-sulfatase to closer approximate the structure of human 4-sulfatase). A monoclonal antibody which selectively reacts with human 4-sulfatase has been used to develop an assay suitable for evaluating human 4-sulfatase enzyme replacement in cat tissues.
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PMID:Immunochemical characterization of feline and human N-acetylgalactosamine 4-sulfatase. 785 82

Mucopolysaccharidosis type VI, or Maroteaux-Lamy syndrome, is a lysosomal storage disorder caused by a deficiency of the enzyme arylsulfatase B (ASB), also known as N-acetylgalactosamine-4-sulfatase. Multiple clinical phenotypes of this autosomal recessively inherited disease have been described. Recent isolation and characterization of the human ASB gene facilitated the analysis of molecular defects underlying the different phenotypes. Conditions for PCR amplification of the entire open reading frame from genomic DNA and for subsequent direct automated DNA sequencing of the resulting DNA fragments were established. Besides two polymorphisms described elsewhere that cause methionine-for-valine substitutions in the arylsulfatase B gene, six new mutations in six patients were detected: four point mutations resulting in amino acid substitutions, a 1-bp deletion, and a 1-bp insertion. The point mutations were two G-to-A and two T-to-C transitions. The G-to-A transitions cause an arginine-for-glycine substitution at residue 144 in a homoallelic patient with a severe disease phenotype and a tyrosine-for-cysteine substitution at residue 521 in a potentially heteroallelic patient with the severe form of the disease. The T-to-C transitions cause an arginine-for-cysteine substitution at amino acid residue 192 in a homoallelic patient with mild symptoms and a proline-for-leucine substitution at amino acid 321 in a homoallelic patient with the intermediate form. The insertion between nucleotides T1284 and G1285 resulted in a loss of the 100 C-terminal amino acids of the wild-type protein and in the deletion of nucleotide C1577 in a 39-amino-acid C-terminal extension of the ASB polypeptide. Both mutations were detected in homoallelic patients with the severe form of the disease. Expression of mutant cDNAs encoding the four amino acid substitutions and the deletion resulted in severe reduction of both ASB protein levels and arylsulfatase enzyme activity in comparison with a wild-type control. The six mutations described in the present study were unique among 25 unrelated mucopolysaccharidosis VI patients, suggesting a broad molecular heterogeneity of the Maroteaux-Lamy syndrome.
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PMID:Mucopolysaccharidosis VI (Maroteaux-Lamy syndrome): six unique arylsulfatase B gene alleles causing variable disease phenotypes. 811 15

Mucopolysaccharidosis type VI (MPSVI, Maroteaux-Lamy syndrome) is a lysosomal storage disease for which multiple clinical phenotypes have been described. A deficiency of the enzyme arylsulfatase B (ASB, N-acetylgalactosamine-4-sulfatase) is the cause of this autosomal recessively inherited disorder. The genotypes of two patients with an intermediate form of MPSVI have been determined by polymerase chain reaction (PCR) amplification of the entire open reading frame of the ASB gene and subsequent direct sequencing of both strands of the PCR fragments by an automated nonradioactive approach. In patient A, a C to T transition in allele I resulting in an exchange of the Arg codon 160 for a premature stop codon (R160*, exon 2), and a G to A transition in allele II leading to a Gln to Arg160 substitution (R160Q, exon 2) were detected. Patient B exhibited a 7-bp deletion in exon 1 of allele I resulting in a frame shift and a premature stop codon 33 triplets 3' of the site of deletion (delta G237-C243), and a C to T transition in allele II giving rise to a Trp to Arg152 substitution (R152W, exon 2). None of these four mutant alleles was present among 60 alleles of the ASB gene in unrelated controls, indicating that the former are not polymorphisms. These results emphasize the broad molecular heterogeneity of Maroteaux-Lamy syndrome and contribute to the establishment of a genotype/phenotype correlation in this disease.
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PMID:Four novel mutant alleles of the arylsulfatase B gene in two patients with intermediate form of mucopolysaccharidosis VI (Maroteaux-Lamy syndrome). 812 75

Mucopolysaccharidosis type VI (MPS VI; Maroteaux-Lamy syndrome) is the lysosomal storage disorder resulting from the deficient activity of N-acetylgalactosamine-4-sulfatase (arylsulfatase B; ASB). MPS VI has been described in man, cats and rats, and several mutations in the ASB gene have been identified in human patients and the animal models. Notably, ASB belongs to a family of sulfatases which are highly conserved, suggesting that they are related evolutionarily and functionally. In this manuscript, four new mutations causing MPS VI are described within the human ASB gene. Each of these mutations occurred in or near the hexapeptide 144GKWHLG149, one of the most highly conserved 'sulfatase' regions. In fact, three of the mutations occurred within the same codon, W146. Thus, these results provide new insights into the molecular lesions causing MPS VI and highlight the importance of this conserved sulfatase region.
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PMID:N-acetylgalactosamine-4-sulfatase: identification of four new mutations within the conserved sulfatase region causing mucopolysaccharidosis type VI. 854 42

Mucopolysaccharidosis (MPS) type VI, the lysosomal storage disorder caused by the deficiency of arylsulfatase B (ARSB) activity, occurs in humans, cats, and rats. To characterize the molecular lesion(s) causing MPS VI in rats, cDNAs encoding rat ARSB were isolated from a rat liver cDNA library. The nucleotide and deduced amino acid sequences of rat ARSB had approximately 80 and 85% identity with the human ARSB sequences, respectively. The chromosomal location of the rat ARSB gene was determined by PCR analysis of rat-mouse somatic cell hybrid panel. The ARSB gene was assigned to rat chromosome 2, where the locus for the MPS VI phenotype in rats has been localized by linkage analysis. To identify the mutation(s) within the ARSB gene causing MPS VI in rats, the ARSB sequence were amplified from affected animals and completely sequenced. Notably, a homoallelic one-base insertion at nucleotide 507 (507insC) was identified, resulting in a frame shift mutation and premature termination at codon 258. The presence of the insertion completely correlated with the occurrence of the MPS VI phenotype among 66 members of the MPR rat colony. Thus, we conclude that 507insC is the causative mutation in these animals and that the MPS VI rats are an authentic model of human MPS VI.
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PMID:Mucopolysaccharidosis type VI in rats: isolation of cDNAs encoding arylsulfatase B, chromosomal localization of the gene, and identification of the mutation. 857 49

Mucopolysaccharidosis VI (MPS VI) is a genetic lysosomal storage disease in which a defect in aryl sulfatase B leads to accumulation of the glycosaminoglycan dermatan sulfate and abnormalities in the development of cartilage and bone. A feline model of this disease was used to evaluate the efficacy of bone marrow transplant (BMT) therapy. Long bones from MPS VI cats (N = 6) and MPS VI + BMT cats (N = 7) were compared with control cats (N = 11) and control + BMT cats (N = 5) in mechanical tests. Dissected femurs and tibias were subjected to three-point bending and a subgroup of tibias were tested with the mechanical response tissue analyzer (MRTA) in which vibration is used to measure tissue impedance. Cats with MPS VI had markedly decreased stiffness and strength in both bone (p < 0.01). There was no significant difference in the MPS VI + BMT group. In the tibias, there was also decreased stiffness and strength in the control + BMT group as compared to controls (p < 0.05). However, when cross-sectional area was used to normalize for bone size there was good correlation with strength in both femurs (r = 0.907, p < 0.01) and tibias (r = 0.915, p < 0.1), and there were no significant differences between groups in the modulus of elasticity. In the tibias, in which stiffness was measured by MRTA, there was significant correlation with three-point bending stiffness. These results indicate that, in cats with MPS VI, the decreases in stiffness and strength of long bones can be largely accounted for by the decrease in bone size (osteopenia) that is present.
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PMID:Bone changes in mucopolysaccharidosis VI in cats and the effects of bone marrow transplantation: mechanical testing of long bones. 857 61

We report studies that suggest enzyme replacement therapy will result in a significant reduction in disease progression and tissue pathology in patients with Maroteaux-Lamy syndrome (Mucopolysaccharidosis type VI, MPS VI). A feline model for MPS VI was used to evaluate tissue distribution and clinical efficacy of three forms of recombinant human N-acetylgalactosamine-4-sulfatase (rh4S, EC 3.1.6.1). Intravenously administered rh4S was rapidly cleared from circulation. The majority of rh4S was distributed to liver, but was also detected in most other tissues. Tissue half-life was approximately 2-4 d. Three MPS VI cats given regular intravenous infusions of rh4S for up to 20 mo showed variable reduction of storage vacuoles in Kupffer cells and connective tissues, however cartilage chondrocytes remained vacuolated. Vertebral bone mineral volume was improved in two MPS VI cats in which therapy was initiated before skeletal maturity, and increased bone volume appeared to correlate with earlier age of onset of therapy. One cat showed greater mobility in response to therapy.
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PMID:Enzyme replacement therapy in a feline model of Maroteaux-Lamy syndrome. 862 70


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