Enzymatic and immunological characterization of the Mycobacterium fortuitum complex.
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The arylsulfatase isozymes of Mycobacterium fortuitum, M. peregrinum, M. chelonei subsp. chelonei, and M. chelonei subsp. abscessus were examined to determine the isozymal and immunological relationship among the members of the M. fortuitum complex. Cell extracts were subjected to electrophoresis on agarose and polyacrylamide gel, and arylsulfatase activity was localized using beta-naphthyl sulfate as substrate. Unique zymograms were produced for M. fortuitum, M. peregrinum, and M. chelonei which were characteristic for each species. The immunological relationship among the sulfatases was assayed by using immunodiffusion and immunoelectrophoresis followed by sulfatase staining for the enzyme. One of the isozymes of M. fortuitum and M. peregrinum cross-reacted, showing immunological identity. Antisera to sulfatases of M. fortuitum and M. peregrinum did not react with sulfatases of M. chelonei. The characterization of sulfatase isozymes in extracts of organisms in the M. fortuitum complex suggests the division of the M. fortuitum complex into two species, M. fortuitum and M. chelonei, with subspecies designations. (+info)
A superfamily of metalloenzymes unifies phosphopentomutase and cofactor-independent phosphoglycerate mutase with alkaline phosphatases and sulfatases.
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Sequence analysis of the probable archaeal phosphoglycerate mutase resulted in the identification of a superfamily of metalloenzymes with similar metal-binding sites and predicted conserved structural fold. This superfamily unites alkaline phosphatase, N-acetylgalactosamine-4-sulfatase, and cerebroside sulfatase, enzymes with known three-dimensional structures, with phosphopentomutase, 2,3-bisphosphoglycerate-independent phosphoglycerate mutase, phosphoglycerol transferase, phosphonate monoesterase, streptomycin-6-phosphate phosphatase, alkaline phosphodiesterase/nucleotide pyrophosphatase PC-1, and several closely related sulfatases. In addition to the metal-binding motifs, all these enzymes contain a set of conserved amino acid residues that are likely to be required for the enzymatic activity. Mutational changes in the vicinity of these residues in several sulfatases cause mucopolysaccharidosis (Hunter, Maroteaux-Lamy, Morquio, and Sanfilippo syndromes) and metachromatic leucodystrophy. (+info)
Sequence analysis of heparan sulphate and heparin oligosaccharides.
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The biological activity of heparan sulphate (HS) and heparin largely depends on internal oligosaccharide sequences that provide specific binding sites for an extensive range of proteins. Identification of such structures is crucial for the complete understanding of glycosaminoglycan (GAG)-protein interactions. We describe here a simple method of sequence analysis relying on the specific tagging of the sugar reducing end by 3H radiolabelling, the combination of chemical scission and specific enzymic digestion to generate intermediate fragments, and the analysis of the generated products by strong-anion-exchange HPLC. We present full sequence data on microgram quantities of four unknown oligosaccharides (three HS-derived hexasaccharides and one heparin-derived octasaccharide) which illustrate the utility and relative simplicity of the technique. The results clearly show that it is also possible to read sequences of inhomogeneous preparations. Application of this technique to biologically active oligosaccharides should accelerate progress in the understanding of HS and heparin structure-function relationships and provide new insights into the primary structure of these polysaccharides. (+info)
The iron sulfur protein AtsB is required for posttranslational formation of formylglycine in the Klebsiella sulfatase.
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The catalytic residue of eukaryotic and prokaryotic sulfatases is a alpha-formylglycine. In the sulfatase of Klebsiella pneumoniae the formylglycine is generated by posttranslational oxidation of serine 72. We cloned the atsBA operon of K. pneumoniae and found that the sulfatase was expressed in inactive form in Escherichia coli transformed with the structural gene (atsA). Coexpression of the atsB gene, however, led to production of high sulfatase activity, indicating that the atsB gene product plays a posttranslational role that is essential for the sulfatase to gain its catalytic activity. This was verified after purification of the sulfatase from the periplasm of the cells. Peptide analysis of the protein expressed in the presence of AtsB revealed that half of the polypeptides carried the formylglycine at position 72, while the remaining polypeptides carried the encoded serine. The inactive sulfatase expressed in the absence of AtsB carried exclusively serine 72, demonstrating that the atsB gene is required for formylglycine modification. This gene encodes a 395-amino acid residue iron sulfur protein that has a cytosolic localization and is supposed to directly or indirectly catalyze the oxidation of the serine to formylglycine. (+info)
A novel mucin-sulphatase activity found in Burkholderia cepacia and Pseudomonas aeruginosa.
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Lung infections due to Burkholderia cepacia and Pseudomonas aeruginosa in patients with cystic fibrosis (CF) are common, are associated with respiratory morbidity and are a cause of mortality. Respiratory mucin in CF patients is highly sulphated, which increases its resistance to bacterial degradation. Desulphation increases the susceptibility of mucin to degradation by bacterial glycosidases and proteinases, and subsequent deglycosylation may facilitate bacterial colonisation by increasing available substrates and binding sites. This study determined whether clinical and environmental strains of B. cepacia and P. aeruginosa had the ability to desulphate mucin. Mucin-sulphatase activity was tested by incubating bacterial cell suspensions with 35S-sulphated mucins purified from LS174T and HT29-MTX human colon carcinoma cell lines. These mucins were also used to test for differences in substrate specificities. Mucin-sulphatase activity was detected in all nine B. cepacia strains and in four of six P. aeruginosa strains. There was strain variability in the level of mucin-sulphatase activity. Aryl-sulphatase activities of Pseudomonas isolates (determined with methylumbelliferyl sulphate) were c. 20-fold higher than those of B. cepacia strains, and were independent of mucin-sulphatase activity. This is the first report to demonstrate desulphation of mucin by B. cepacia and P. aeruginosa. It is concluded that B. cepacia and P. aeruginosa produce one or more cell-bound glycosulphatase(s), in addition to aryl-sulphatase activity. Mucin-sulphatase activity of B. cepacia and P. aeruginosa may contribute to their association with airway infections in patients with cystic fibrosis. (+info)
Ontogeny of estrogen sulfatase activity in ovine fetal hypothalamus, hippocampus, and brain stem.
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Ovine parturition is initiated by increases in fetal hypothalamus-pituitary-adrenal (HPA) axis activity, which in turn increase placental estrogen biosynthesis and ultimately increase uterine contractility. In addition to the action in the uterus, estrogens augment fetal ACTH secretion. In late gestation, estrone sulfate is more abundant in fetal plasma than is unconjugated estrone. We studied hypothalamus, hippocampus, and brain stem tissue from fetal, neonatal, and adult sheep to test the hypothesis that the ovine brain contains estrogen sulfatase activity. We found that the activity in the hippocampus was significantly increased in late-gestation fetuses compared with both younger and older animals. No significant change in either hypothalamus or brain stem was revealed; however, the activity in all brain areas was high. Immunohistochemistry revealed the presence of estrogen sulfatase in the paraventricular nucleus of the hypothalamus, the nucleus of the solitary tract, and the rostral ventrolateral medulla. We conclude that ovine fetal hypothalamus, hippocampus, and brain stem contain estrogen sulfatase activity and that the activity in the hippocampus is developmentally regulated. (+info)
Screening for novel pancreatic genes expressed during embryogenesis.
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We have combined suppressive subtractive hybridization with in situ hybridization to identify genes expressed at early stages of pancreas development. By using polymerase chain reaction amplification and subtractive hybridization, this protocol for screening can be applied when the amount of RNA is limited. Seven genes expressed in or adjacent to the pancreas anlage were isolated, three of which show similarity to known genes. The expression pattern and sequence information indicate that some of the genes could govern pancreas development. (+info)
Iduronate sulfatase analysis of hair roots for identification of Hunter syndrome heterozygotes.
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Iduronate sulfatase, the enzyme deficient in Hunter syndrome, can be readily measured in individual hair roots. Samples from Hunter syndrome hemizygotes had activities at or near the limits of detection. Samples from two mothers of Hunter syndrome patients, one an obligate heterozygote, had lower average iduronate sulfatase activity than the normal mean, and a significant number of hair roots had activity in the pathognomic range. A third mother showed a normal distribution of enzyme activity, and no hair roots were in the range of those from an affected individual. These results are similar to studies on the distribution of other X-linked enzymes in individual hair root samples from heterozygotes. This suggests that hair root iduronate sulfatase assessment is useful in the detection of Hunter syndrome carrier status, but further refinement of the test system is necessary. (+info)