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

---

Query: EC:6.3.4.6 (urease)
7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new rapidly growing mycobacterium was isolated from human sputum. This organism grew at 22, 31, 37, and 41 degrees C and possessed catalase, acid phosphatase, acetamidase, urease, nicotinamidase, pyrazinamidase, and nitrate reductase activities. It did not produce nicotinic acid, hydrolyze Tween, or have benzamidase, isonicotinamidase, succinidamidase, and arylsulfatase activities. A mycolic acid analysis revealed a simple, unique pattern. The organism is susceptible to antituberculotic drugs. A comparative 16S rRNA sequence analysis placed this organism within the confines of the genus Mycobacterium, most closely related to the thermotolerant rapidly growing species. On the basis of the pattern of enzymatic activities and metabolic properties, as well as the unique 16S rRNA sequence, we propose that our single strain represents a new species, for which we propose the name Mycobacterium confluentis. The type strain is strain 1389/90; a culture of this strain has been deposited in the German Collection of Microorganisms and Cell Cultures as strain DSM 44017.
...
PMID:Mycobacterium confluentis sp. nov. 137 23

In accordance with Recommendation 30b of the International Code of Nomenclature of Bacteria, which calls for the development of recommended minimal standards for describing new species, we propose minimal standards for describing the genus Mycobacterium and new slowly growing species of this genus. The minimal standards for assignment of a strain to the genus Mycobacterium include acid-alcohol fastness, a DNA G+C content in the range from 61 to 71 mol%, and mycolic acid detection with characterization of C22 to C26 pyrolysis esters. The recommended minimal standards for describing a new slowly growing Mycobacterium species are based on the results of phenotypic and genomic studies and include the results of the following conventional tests: growth at 25, 30, 33, 37, 42, and 45 degrees C; pigmentation; resistance to isoniazid, thiophene-2-carboxylic acid hydrazide, hydroxylamine, p-nitrobenzoic acid, sodium chloride, thiacetazone, picrate, and oleate; catalase activity; Tween hydrolysis; urease activity; niacin detection; and nitrate reductase, acid phosphatase, arylsulfatase, pyrazinamidase, and alpha-esterase activities. In addition, a mycolic acid profile should be determined, and DNA-DNA hybridization experiments in which the difference between the denaturation temperature of the homologous reaction and the denaturation temperature of the heterologous reaction is determined should be performed. This proposal has been endorsed by the members of the Subcommittee for Taxonomy of the Mycobacteria of the International Committee on Systematic Bacteriology.
...
PMID:Proposed minimal standards for the genus Mycobacterium and for description of new slowly growing Mycobacterium species. 158 Nov 93

Hyperammonemia interferes with normal brain function. The effect of ammonia on free and membrane-bound lysosomal enzymes and on mucopolysaccharide metabolism was studied in cultured rat brain cells (ROC-1, hybridoma between C6-astrocytoma and oligodendrocytes). Intralysosomal ammoniagenesis was achieved from urea by endocytosed Jackbean urease followed by incubation of the cultures with urea. The intralysosomal location of urease was evidenced by the protective effects of leupeptin and urea on the stability of intracellular urease. Ammonia formed from urea resulted in an increased secretion of lysosomal arylsulfatase-A (AS-A), but not of the membrane-bound lysosomal beta-glucosidase into the culture medium, thus intralysosomal AS-A activity decreased. Lysosomal, membrane-bound beta-glucosidase activity increased, presumably due to intralysosomal proteolytic protection following an increased lysosomal pH. Intralysosomal ammoniagenesis temporarily impaired 35SO4-glycosaminoglycan degradation of prelabeled cells. The results support the hypothesis that hyperammonemic states may interfere with lysosomal functions in vivo as well in cultured cells.
...
PMID:Intralysosomal generation of ammonia from urea by endocytosed urease results in secretion of free lysosomal arylsulfatase-A and increased activity of membrane-bound beta-glucosidase in cultured brain cells. 168 84

When leprosy bacilli grown in nude mouse foot pad were used for culture experiments, cultivable acid-fast bacillus was sometimes isolated as a contaminant. Whenever bacilli were inoculated to nude mice, the same leprosy bacilli were killed by autoclaving and were inoculated in to foot pads of 5 nude mice for examination of this cause of the contamination. Acid-fast bacillus was cultivated on 3% Ogawa egg medium at 33 degrees C from homogenates of foot pads of nude mice infected with M. leprae after one year and a while of infection. Foot pad of nude mouse injected with leprosy bacilli was cut off, ground in mortar and passed through sterile absorbent cotton and the filtrate was centrifuged at 10,000 rpm for 30 minutes. The sediment was inoculated on 3% Ogawa egg medium after treating with a small amount of sterile 1 N sodium hydroxide. Acid-fast bacilli were isolated from 3 out of 41 mice inoculoted with heat killed bacilli. The isolated acid-fast bacillus did not be observed in the same experimental group inocudated with live bacilli, positive cases were scattered in another groups. Four out of 16 tubes were positive for acid-fast bacilli in mice infected with Kurume-naha and 5 out of 7 tubes in the Amami-KM infected mouse group. The two negative tubes were discarded due to contamination. Kurume-Oki strain which has yellow colonial morphology was isolated from one out of 6 culture tubes. Strains Kurume-naha and Amami-KM have the same characteristics as follows: slow grower with pale yellow smooth colonial morphology, strongly positive for niacin production and ureas; positive for nicotinamidase, pyradinamidase and 68 degrees C catalase; no growth at 45 degrees C, negative for nitrate reduction, hydrolysis of Tween 80, diamine oxidase, heat stable acid-phosphatase and arylsulphatase; resistant to streptomycin, isoniazid, rifampicin and B 663. Two isolates were identified as Mycobacterium simiae from these characteristics. Characteristics of a Kurume-Oki isolate was as follows: slow grower with yellow smooth colonial morphology, positive for urease, 68 degrees C catalase, hydrolysis of Tween 80 and arylsulfatase; no growth at 45 degrees C, negative for niacin production, nicotinamidase, pyradinamidase, nitrate reduction, daimine oxidase and heat stable acid-phosphatase; resistant to streptomycin, isoniazid, rifampicin and B. 663. This bacillus was identified as Mycobacterium gordonae from these characteristics.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:[Acid-fast bacilli isolated from foot pads of nude mice infected with leprosy bacilli]. 213 33

The effect of Tween 80 on the growth of Mycobacterium avium complex (MAC) in liquid culture condition was investigated. Observation of the colony-forming units (CFU) and the morphology of MAC with transmission and scanning electron microscopy showed that Tween 80 at 0.05% in the medium (ca. 0.5 mg/ml) had bacteriostatic action and caused cell elongation. Tween 80 at 0.5% or more in the medium (ca. 5 mg/ml) reduced the quantity of MAC glycolipids and also led to false positive or positive results in biochemical tests for mycobacterial identification using nitrate reductase, urease, or arylsulfatase. To determine whether or not surfactants could reduce the MAC permeability barrier, the minimal inhibitory concentration (MIC) of antituberculosis drugs on MAC was determined in liquid medium with or without several kinds of surfactants including Tween 80. Five surfactants including Tween 80 increased the activity of antituberculosis drugs to MAC. These findings suggest that Tween 80 acts directly on the cell wall of MAC.
...
PMID:Effect of Tween 80 on the growth of Mycobacterium avium complex. 228 Jul 23

Cat leprosy bacilli passaged in mice could be isolated on 1% Ogawa yolk medium. The isolated cat leprosy bacilli which were cultivated successively four times on 1% Ogawa yolk medium produced a leproma in mice. All characteristics of the isolated cat leprosy bacillus were the same as isolated murine leprosy bacillus, as follows: slow grower, light yellowish-white rough colony, production of much coproporphyrin on the medium, heat-resistant catalase negative, heat-resistant phosphatase negative, arylsulfatase negative, niacin negative, hydrolysis of Tween 80 negative, urease negative, nicotinamidase positive, pyrazinamidase positive, cytochrome b1 at 560 nm positive, cytochrome a2 at 630 nm positive, and cytochrome c at 550 nm negative. Cats are susceptible to both cat and murine leprosy bacilli; the bacilli produced a leproma in a newborn cat at 3 to 4 months and in an adult cat at 2 months after inoculation. Many globi of acid-fast bacilli (AFB) were observed in the histopathological sections and the smear preparations of the newborn cat's lepromas, especially in the necrotic areas of the lepromas. Many AFB and polymorphonuclear leukocytes were seen in the histopathological sections and the smear preparations of the adult cat's lepromas. These lepromas formed ulcers by autolysis and healed or absorbed without ulcer formation over the course of months. Large lepromas remained for a long time without ulcer formation and caseation in some cats. Secondary infections with cat and murine leprosy bacilli were done respectively to the right and left femoral subcutaneous regions of newborn cats carrying primary lepromas. After one month, granulomas in which many AFB were observed were produced in both infection sites. Cats are susceptible to infection with cat and murine leprosy bacilli; however, the bacilli did not invade progressively to internal organs or other subcutaneous areas. Cat leprosy bacilli which were passaged in the mouse are identical to murine leprosy bacilli.
...
PMID:Identification of cat leprosy bacillus grown in mice. 354 48

Biochemical activities of 20 wild-type strains and of 2 laboratory strains of Mycobacterium paratuberculosis were evaluated. Biochemical activities evaluated were growth at 30 C, 37 C, and 42 C; production of urease, niacin, pyrazinamidase, arylsulfatase, and catalase; hydrolyzation of Tween 80; reduction of nitrate and tellurite; and growth in 5% NaCl. Antimicrobial susceptibility to thiophene-2-carboxylic acid hydrazide (10 micrograms/ml), neotetrazolium chloride (1:40,000), streptomycin (2 micrograms/ml), rifampin (0.25 micrograms/ml), and isoniazid (10 micrograms/ml) also was determined. Generally, M paratuberculosis was biochemically inactive, with only a few strains producing pyrazinamidase and maintaining catalase activity after heating. All strains grew optimally at 37 C, grew slightly at 30 C, and did not grow at 42 C. Wild-type strains did not grow in the presence of neotetrazolium chloride, streptomycin, and rifampin, and grew in the presence of thiophene-2-carboxylic acid hydrazide and isoniazid. Although biochemical evaluation can be used as an aid in the identification of M paratuberculosis, growth rate, and mycobactin dependency remain major criteria for positive identification.
...
PMID:Biochemical characteristics of various strains of Mycobacterium paratuberculosis. 374 Jun 13

Benzoyl- and isopentenoyl phosphoric triamides (BPA and IPA) strongly inhibited urease activities from jack bean, soybean, watermelon seed, Proteus mirabilis, P. rettgeri, P. vulgaris, Mycobacterium smegmatis, and Ureaplasma urealyticum. Their I50 values (the final concentration causing 50% inhibition), independent of enzyme source, were 2-21 nM, which are about 1,000-fold lower than that of caprylohydroxamic acid, one of the most potent urease inhibitors. ATP-urea amidolyase activity was inhibited 50% by BPA at a higher concentration of 0.28 mM, but was not affected by IPA even at 1.3 mM. Thirteen kinds of hydrolases (trypsin, chymotrypsin, thermolysin, leucine aminopeptidase, papain, lipase, alpha-amylase, glucuronidase, asparaginase, arylsulfatase, alkaline phosphatase, acid phosphatase, and true cholinesterase), two oxidoreductases (catalase and alcohol dehydrogenase), three transferases (glutamic-oxaloacetic aminotransferase, gamma-glutamyl transpeptidase, and arylsulfotransferase) and two kinases (pyruvate kinase and creatine kinase) were not affected at all even at 1 mM BPA and IPA. Exceptionally, pseudo-cholinesterase from human serum was inhibited by BPA and IPA, whose I50 values were 70 nM and 10 muM, respectively, using acetylthiocholine as a substrate. These values increased to 0.55 muM and 54 muM, respectively, when acetylcholine was used as a substrate. These results show that N-acylphosphoric triamides potently and specifically inhibit urease activity at concentrations of nM order.
...
PMID:Specific inhibition of urease by N-acylphosphoric triamides. 384 42

The characteristics of an unclassified Mycobacterium sp. isolated from three patients with Crohn's disease are presented. The organism is extremely fastidious and mycobactin dependent and may require up to 18 months of incubation for primary isolation. Colony morphology is rough. Characteristics are unlike those of any presently defined species. The isolates produced postive niacin, catalase, and 2-week arylsulfatase reactions and were susceptible to neotetrazolium chloride (1:40,000), streptomycin (2 micrograms/ml), and rifampin (0.25 micrograms/ml). Chromogenicity, nitrate reduction, quantitative catalase, Tween hydrolysis, urease, tellurite reduction, pyrazinamidase, and 3-day arylsulfatase tests were negative, and the isolates were resistant to thiophene-2-carboxylic acid hydrazide (10 micrograms/ml) and isoniazid (10 micrograms/ml). Optimum growth in broth was determined to be in 7H9 medium with Dubos oleic albumin complex, Tween 80, and mycobactin J at 37 degrees C without CO2 or agitation and in low medium depth. This Mycobacterium sp. may be a subspecies or biovariant of Mycobacterium paratuberculosis, or it may represent a new species of Mycobacterium. It is suggested that this Mycobacterium sp. may play an etiological role in some cases of Crohn's disease.
...
PMID:Characteristics of an unclassified Mycobacterium species isolated from patients with Crohn's disease. 651 78

The biochemical tests, namely, niacin, catalase, nitrate reduction, tween hydrolysis, tellurite reduction, arylsulfatase and urease tests were carried out for all the mycobacteria which are immunogenically closely related to M. leprae. Among them only M. vaccae shows closest relationship with M. leprae when compared with its communicated data. Except for the tellurite reduction test which was variable in case of M. leprae, all the other tests were found similar to that of M. leprae. In the next experiment, the thin-layer chromatographic pattern of mycolates from M. leprae has been compared with that of M. leprae. The presence of Keto-mycolate in the cell wall structure of both M. vaccae and M. leprae also reflects their biochemical relationship at their ultrastructural level.
...
PMID:Biochemical correlation of M. vaccae with M. leprae. 675 76


1 2 3 4 5 6 7 Next >>

---