Polymorphisms in Tunisian patients with N-acetylgalactosamine-6-sulfate sulfatase gene deficiency: implication in Morquio A disease. (17/36)


Hydrolytic enzyme production by Clostridium difficile and its relationship to toxin production and virulence in the hamster model. (18/36)

Thirty isolates of Clostridium difficile expressing different degrees of toxigenicity and virulence in an animal model were assayed for the production of chondroitin-4-sulphatase, hyaluronidase, heparinase, collagenase and protease. All strains demonstrated some hydrolytic enzyme activity. There was no direct correlation between toxigenic status, or virulence, and hydrolytic enzyme production. However, all five strains known to be highly virulent in the hamster model had hyaluronidase, chondroitin-4-sulphatase and collagenase activity whereas only three of five toxigenic but poorly virulent strains had these activities, the collagenase activity being weak in all three cases. The only two proteolytic strains are also highly virulent. The potential tissue damaging properties of these hydrolytic enzymes may help to explain the differences in virulence of C. difficile strains seen in the Syrian hamster model of antibiotic-associated colitis, and may contribute to the spectrum of disease seen in man. It is also possible that chondroitin-4-sulphatase, hyaluronidase and collagenase activity may release essential nutrients, promoting establishment of C. difficile in the gut.  (+info)

Biomarker analysis of Morquio syndrome: identification of disease state and drug responsive markers. (19/36)


Exposure to common food additive carrageenan leads to reduced sulfatase activity and increase in sulfated glycosaminoglycans in human epithelial cells. (20/36)


The structure of human GALNS reveals the molecular basis for mucopolysaccharidosis IV A. (21/36)


Effect of culture conditions and signal peptide on production of human recombinant N-acetylgalactosamine-6-sulfate sulfatase in Escherichia coli BL21. (22/36)

The production and characterization of an active recombinant N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in Escherichia coli BL21(DE3) has been previously reported. In this study, the effect of the signal peptide (SP), inducer concentration, process scale, and operational mode (batch and semi-continuous) on GALNS production were evaluated. When native SP was presented, higher enzyme activity levels were observed in both soluble and inclusion bodies fractions, and its removal had a significant impact on enzyme activation. At shake scale, the optimal IPTG concentrations were 0.5 and 1.5 mM for the strains with and without SP, respectively, whereas at bench scale, the highest enzyme activities were observed with 1.5 mM IPTG for both strains. Noteworthy, enzyme activity in the culture media was only detected when SP was presented and the culture was carried out under semi-continuous mode. We showed for the first time that the mechanism that in prokaryotes recognizes the SP to mediate sulfatase activation can also recognize a eukaryotic SP, favoring the activation of the enzyme, and could also favor the secretion of the recombinant protein. These results offer significant information for scaling-up the production of human sulfatases in E. coli.  (+info)

Hydrolytic enzymes of "Streptococcus milleri". (23/36)

Seventy-two isolates classified as "Streptococcus milleri" were examined for the presence of various hydrolytic enzymes. While no protein or lipid-degrading activities were demonstrated, some isolates showed DNase and mucopolysaccharide-degrading activities. Beta-hemolytic isolates were more likely to produce these enzymes than were nonhemolytic strains. Isolates of one "S. milleri" biotype (mannitol fermentation positive) were uniformly devoid of all enzyme activities tested.  (+info)

Purification and properties of N-acetylgalactosamine 6-sulphate sulphatase from human placenta. (24/36)

1. N-Acetylgalactosamine 6-sulphate sulphatase was purified about 20000-fold from the soluble extract of human placenta with N-acetylgalactosamine 6-sulphate-glucuronic acid-N-acetyl[1-(3)H]galactosaminitol 6-sulphate as substrate in the activity assay. The enzyme appears to be a glycoprotein with a mol.wt. of about 100000 as determined by gel filtration. On gel electrophoresis in the presence of sodium dodecyl sulphate the major protein band had a mol.wt. of 78000. Variable charge heterogeneity was observed in several enzyme preparations. 2. The purified enzyme released up to one sulphate molecule from the disulphated trisaccharide. It was active towards N-acetylgalactosamine 6-sulphate and exhibited no measurable N-acetylglucosamine 6-sulphate sulphatase or any other known lysosomal sulphatase activity. Hydrolysis of [1-(3)H]galactitol 6-sulphate was achieved by incubation neither with a crude nor with a purified enzyme preparation. Chondroitin 6-sulphate and keratan sulphate, as well as heparin and heparan sulphate, served as competitive inhibitors of the enzyme. 3. Purified N-acetylgalactosamine 6-sulphate sulphatase activity was optimal at pH4.9 and 4.4 when assayed in 0.02m-sodium acetate buffer and at pH4.2 and 5.2 in 0.1m-sodium acetate buffer. A single pH-optimum at pH4.8 was observed for the crude enzyme and for the purified enzyme after mild periodate treatment. The sulphatase activity was inhibited by a variety of anions and cations and activated by thiol-specific and thiol reagents.  (+info)