Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clostridium perfringens can obtain sialic acid from host tissues by the activity of sialidase enzymes on sialoglycoconjugates. After sialic acid is transported into the cell, sialic acid lyase (NanA) then catalyzes the hydrolysis of sialic acid into pyruvate and N-acetylmannosamine. The latter is converted for use as a biosynthetic intermediate or carbohydrate source in a pathway including an epimerase (NanE) that converts N-acetylmannosamine-6-phosphate to N-acetylglucosamine-6-phosphate. A 4.0-kb DNA fragment from C. perfringens NCTC 8798 that contains the nanE and nanA genes has been cloned. The identification of the nanA gene product as sialic acid lyase was confirmed by overexpressing the gene and measuring sialic acid lyase activity in a nanA Escherichia coli strain, EV78. The nanA gene product was also shown to restore growth to EV78 in minimal medium with sialic acid as the sole carbon source. By using Northern blot experiments, it was demonstrated that the nanE and nanA genes comprise an operon and that transcription of the operon in C. perfringens is inducible by the addition of sialic acid to the growth medium. The Northern blot experiments also showed that there is no catabolite repression of nanE-nanA transcription by glucose. With a plasmid construct containing a promoterless cpe-gusA gene fusion, in which beta-glucuronidase activity indicated that the gusA gene acted as a reporter for transcription, a promoter was localized to the region upstream of the nanE gene. Primer extension experiments then allowed us to identify a sialic acid-inducible promoter located 30 bp upstream of the nanE coding sequence.
 ...
PMID:Cloning, sequence, and transcriptional regulation of the operon encoding a putative N-acetylmannosamine-6-phosphate epimerase (nanE) and sialic acid lyase (nanA) in Clostridium perfringens. 1041 49

Strong phospholipase A (PLA) and phospholipase C (PLC) activities as potential virulence factors are the outstanding characteristics of eight strains of small oral spirochaetes isolated from deep periodontal lesions. By qualitative dot-blot DNA-DNA hybridization and 16S rDNA sequence comparison, these spirochaetes form a distinct phylogenetic group, with Treponema maltophilum as its closest cultivable relative. Growth of these treponemes, cells of which contain two endoflagella, one at each pole, was autoinhibited by the PLA-mediated production of lysolecithin unless medium OMIZ-Pat was prepared without lecithin. N-Acetylglucosamine was essential and D-ribose was stimulatory for growth. All isolates were growth-inhibited when 1% foetal calf serum was added to the medium. Growth on agar plates supplemented with human erythrocytes produced haemolysis. In addition to PLA and PLC, the new isolates displayed strong activities of alkaline and acid phosphatases, beta-galactosidase, beta-glucuronidase, N-acetyl-beta-glucosaminidase and sialidase, intermediate activities of C4- and C8-esterases, naphthol phosphohydrolase and alpha-fucosidase and a distinctive 30 kDa antigen detectable on Western blots. This phenotypically and genotypically homogeneous group is proposed as a novel species, Treponema lecithinolyticum sp. nov., with isolate OMZ 684T designated as the type strain. A molecular epidemiological analysis using a T. lecithinolyticum-specific probe showed this organism to be associated with affected sites when compared with unaffected sites of periodontitis patients. This association was more pronounced in patients with rapidly progressive periodontitis than in those with adult periodontitis.
 ...
PMID:Treponema lecithinolyticum sp. nov., a small saccharolytic spirochaete with phospholipase A and C activities associated with periodontal diseases. 1055 10

Rat liver microsomal and lysosomal beta-glucuronidase-derived glycopeptides were obtained by extensive Pronase digestion followed by N-[14C]acetylation and desialylation by neuraminidase treatment. These glycopeptides were studied by sequential chromatography on lectin-affinity columns such as concanavalin A, lentil lectin, Phaseolus vulgaris erythroagglutinin, Ricinus communis agglutinin I, Triticum vulgaris agglutinin, Glycine max agglutinin and Ulex europaeus agglutinin. Using serial lectin affinity chromatography approach combined with neuraminidase treatment allowed us to show the unexpected presence of complex tri- and/or tetraantennary type glycans (40.8 and 17.0% for microsomal and lysosomal enzyme, respectively). Moreover, the application of neuraminidase treatment revealed that complex biantennary type glycans, present on lysosomal beta-glucuronidase, are almost fully sialylated while the same type of glycans present on microsomal enzyme do not contain sialic acid. Furthermore, the results obtained confirmed that microsomal and lysosomal beta-glucuronidases possess high mannose and/or hybrid type glycans (19.6 and 36.6%, respectively), and complex biantennary type glycans (38.9 and 46.4%, respectively).
 ...
PMID:Affinity chromatography of branched oligosaccharides in rat liver beta-glucuronidase. 1139 3

Fasciola hepatica secretes proteolytic enzymes and other molecules that are essential for host penetration and migration. This mixture may include enzymes required for the degradation of supramucosal gels, which defend epithelial surfaces against pathogen entry. These contain hydrated mucins that are heavily glycosylated. Excretory-secretory products (ES) from F. hepatica were examined for a range of glycosidase activities, using synthetic 4-methylumbelliferyl glycosides as substrates. The ES product contained at least 8 different glycosidase activities, the most abundant of which were beta-N-acetylhexosaminidase, beta-galactosidase and beta-glucosidase. Alpha-fucosidase, beta-glucuronidase, alpha-galactosidase, alpha-mannosidase and neuraminidase were also present. Beta-N-acetylhexosaminidase and beta-galactosidase were present in multiple isoforms (at least 4), whereas beta-glucosidase appeared to exist as one isoenzyme with a pI < 3.8. All three enzymes had acidic pH optima (4.5-5.0). Ovine small intestinal mucin was degraded by ES at pH 4.5 or 7.0, with or without active cathepsin L, the major protease found in F. hepatica ES. The ability of F. hepatica ES to degrade mucin in the presence or absence of active cathepsin L suggests that cathepsin L is not essential for mucin degradation. The abundance of beta-galactosidase and beta-hexosaminidase in ES supports a role for these enzymes in mucin degradation.
 ...
PMID:Glycosidase activity in the excretory-secretory products of the liver fluke, Fasciola hepatica. 1552 35

A 37-year-old woman presented for routine obstetrical care at 15 weeks' gestational age and the fetus was found to have hydrops fetalis. Following elective termination of the pregnancy at 18 weeks' gestational age, pathologic examination of the female conceptus revealed findings suggestive of a lysosomal storage disease within the liver and cardiac muscle. Enzyme assays for beta-galactosidase, neuraminidase, alpha-l-iduronidase, beta-glucuronidase, beta-glucosidase, Morquio disease type A enzyme, beta-fucosidase, alpha-mannosidase, and beta-mannosidase were all normal, ruling out many of the common storage diseases. Electron microscopy identified vacuoles within hepatocytes, Kupffer cells, and cardiac myocytes resembling the autophagic vacuoles characteristic of a group of diseases known as the autophagic vacuolar myopathies (AVMs). Because these diseases are exceptionally rare in females, and because such autophagic vacuoles have never before been described in liver, we propose a novel entity of "AVM-like lysosomal storage disease" presenting as nonimmune hydrops in a female fetus.
 ...
PMID:An autophagic vacuolar myopathy-like disorder presenting as nonimmune hydrops in a female fetus. 1924 13


<< Previous 1 2 3 4