Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A rapid simplified screening method that selectively detected the urease activity of 99.6% of 286 isolates of Cryptococcus neoformans within 15 min was developed for use in clinical microbiology laboratories.
J Clin Microbiol 1979 Sep
PMID:Rapid selective urease test for presumptive identification of Cryptococcus neoformans. 38 22

Urinary stones form as a consequence of urinary supersaturation. Supersaturation occurs as a result of elevated concentrations of urinary solutes. Dietary, metabolic, endocrine, hereditary, and infectious processes alter urinary solute concentrations. Struvite (MgNH4PO. 6H2O) and carbonate-apatite [Ca10(PO4)6CO3] stones form in urine that becomes supersaturated as a by-product of the hydrolysis of urea by the bacterial enzyme urease. Urease-induced stones manifest primarily as branched renal calculi and as bladder calculi. Conventional therapy has usually consisted of surgical removal of the stone combined with a short course of antimicrobial therapy. Such treatment is curative in about 50% of cases. Recurrent stone formation and progressive pyelonephritis occur in those who are not cured. Adjunctive medical treatment with acetohydroxamic acid or hydroxyurea lessens the risk of calculogenesis and decreases growth of residual stones in patients who are not cured by conventional therapy. Patients with urea-splitting urinary infection and renal stones have a major life-threatening disease. The morbidity and expense that result from this disease are great. Long-term (perhaps lifetime) chemotherapy with antimicrobial agents and/or urease-inhibiting drugs combined with judicious and expert surgical intervention can be expected to significantly improve the plight of these unfortunate patients.
Urol Res 1979 Sep
PMID:Urease stones. 38 98

Certain tRNAs in S. cerevisiae (tRNATyr and tRNAPhe) arise via precursor molecules which are mature at the 5' and 3' termini but contain intervening sequences adjacent to the anticodon (Knapp et al., 1978; O'Farrell et al., 1978). In addition to these molecules, precursors to several other tRNAs accumulate in a temperature-sensitive mutant (ts136) at the nonpermissive temperature. We have analyzed one of these species and shown that it is a precursor to a minor species of tRNASer. This precursor is also mature at both termini and contains an intervening sequence of 19 nucleotides adjacent to the hypermodified A residue 3' to the anticodon. The sequence can be arranged in a secondary structure in which the anticodon stem is extended by additional base-pairing, and contains the sites of excision and ligation within two looped regions. Support for this structure was provided by analysis of the products of limited digestion with RNAase T1. recently Piper (1978) reported the isolation of a minor species of tRNASer which decodes UCG. He found this species to be structurally heterogeneous and determined that the less abundant form corresponds to the tRNA which is altered in the recessive lethal SUP-RL1 amber suppressor. Our data now suggest that the more abundant form may be restricted to reading UCA in vivo; thus mutation of the minor species would result in complete loss of UCG-decoding ability and explain the recessive lethality of SUP-RL1. We have shown that the precursor which accumulates in ts136 corresponds exclusively to this minor tRNASerUCG species. Our results suggest that this may be the only gene for tRNASer in yeast which contains an intervening sequence.
Cell 1979 Sep
PMID:A precursor to a minor species of yeast tRNASer contains an intervening sequence. 38 30

A total of 387 yeasts from the contents of the digestive tracts of domestic animals and poultry were identified by slide agglutination tests using factor antisera and urease tests. The results of this serological test were very satisfactory with respect to accuracy and rapidity, particularly when performed in combination with concomitant physiological tests only for assimilation of inositol and potassium nitrate. It may be concluded that such a combination of serological and biological tests is very useful for identifying yeast strains from various sources.
Sabouraudia 1979 Sep
PMID:Rapid identification of yeasts by serological methods: a combined serological and biological method. 39 60

Papain (EC 3.4.22.2) has been coupled to supports of titanium (IV) oxide and cellulose, which are particulate and pre-coated with diazotised 1,3-diaminobenzene, giving water-insoluble and stable derivatives which possess low proteolytic activity but high esterolytic activity. In addition the reversible binding of zinc (II) at the active site of papain has been exploited to inhibit protectively the enzyme during its linkage to the aforementioned supports, thereby yielding water-insoluble derivatives of papain having superior activity upon reactivation with EDTA. Application of the improved procedure of enzyme coupling to macroporous cellulose particles gave a water-insoluble derivative of papain having further enhanced proteolytic activity. Other properties of the water-insoluble derivatives of papain and of similarly prepared water-insoluble conjugates of urease (EC 3.5.1.5) and cholinesterase (EC 3.1.1.8) with cellulose are also reported.
Biochim Biophys Acta 1977 Sep 15
PMID:Active water-insoluble derivatives of papain and other enzymes based on preformed diazonium-type supports. 40 36

Urease was bound to commercially available nonwoven nylon fabric filters. Multilayer immobilized-enzyme filter reactors were constructed by packing varying numbers of urease-nylon filters in a column. Owing to the relatively open structure and high mechanical strength of the filter fabric, compaction and pressure drop effects were minimal. The reactors could be operated in a wide range of substrate concentrations and flow rates under conditions where mass-transfer limitations could be neglected. The kinetic behavior of the immobilized-enzyme filter reactors could be described by a linear form of the integrated Michaelis-Menten equation using a model based on the sequential action of the enzyme filters.
Biotechnol Bioeng 1979 Sep
PMID:Multilayer immobilized-enzyme filter reactors: urease bound to nylon fabric filters. 49 73

Priority of the name Malassezia pachydermatis (Weidman) Dodge 1935 is indicated for the microorganism which has been called Pityrosporum pachydermatis Weidman 1925 and P. canis Gustafson 1955. M. pachydermatis is here further characterized in culture with information drawn from 2 recent isolates, in particular the presence of spiral grooves on the inner surface of the cell wall, good growth on Mycosel agar, rapid production of urease, and assimilation of glucose by the Wickerham method.
Sabouraudia 1979 Sep
PMID:Malassezia pityrosporum pachydermatis (Weidman) Dodge 1935. 53 21

A heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio)propionate, was synthesized. Its N-hydroxysuccinimide ester group reacts with amino groups and the 2-pyridyl disulphide structure reacts with aliphatic thiols. A new thiolation procedure for proteins is based on this reagent. The procedure involves two steps. First, 2-pyridyl disulphide structures are introduced into the protein by the reaction of some of its amino groups with the N-hydroxysuccinimide ester sie of the reagent. The protein-bound 2-pyridyl disulphide structures are then reduced with dithiothreitol. This reaction can be carried out without concomitant reduction of native disulphide bonds. The technique has been used for the introduction of thiol groups de novo into ribonuclease, gamma-globulin, alpha-amylase and horseradish peroxidase. N-Succinimidyl 3-(2-pyridyldithio)propionate can also be used for the preparation of protein-protein conjugates. This application is based on the fact that protein-2-pyridyl disulphide derivatives (formed from the reaction of non-thiol proteins with the reagent) react with thiol-containing proteins (with native thiols or thiolated by, for example, the method described above) via thiol-disulphide exchange to form disulphide-linked protein-protein conjugates. This conjugation technique has been used for the preparation of an alpha-amylase-urease, a ribonuclease-albumin and a peroxidase-rabbit anti-(human transferrin) antibody conjugate. The disulphide bridges between the protein molecules can easily be split by reduction or by thiol-disulphide exchange. Thus conjugation is reversible. This has been demonstrated by scission of the ribonuclease-albumin and the alpha-amylase-urease conjugate into their components with dithiothreitol. N-Succinimidyl 3-(2-pyridyldithio)propionate has been prepared in crystalline form, in which state (if protected against humidity) it is stable on storage at room temperature (23 degrees C).
Biochem J 1978 Sep 01
PMID:Protein thiolation and reversible protein-protein conjugation. N-Succinimidyl 3-(2-pyridyldithio)propionate, a new heterobifunctional reagent. 70 70

Significant differences have been proved between strains of E. coli isolated from neonatal E. coli diarrhoea (N.C.D.) and post weaning diarrhoea (P.W.D.). The biochemical differences were pronounced in the criteria sucrose, dulcitol, adonitol and urease when comparing the total number of strains from the two syndromes. However, adonitol positive strains were only found among strains of the serogroup O 149:K91(B) of which all the N.C.D.. strains were positive and only 8 of the 86 P.W.D. strains were adonitol fermenters. The dominant fermentation pattern of the N.C.D. strains were sucrose--, dulcitol--, urease--. Contrary the P.W.D. strains were sucrose +, dulcitol +, and 56.6 per cent urease + (Table III). In the possible plasmid determined characters significant differences were found in the ability to produce the K88 antigen and the colicins. The K88 antigen was demonstrated in 97.9 per cent of the N.C.D. strains and 6.2 per cent of the P.W.D. strains whereas 40.6 and 79.6% respectively were colicinogenic. In the serogroup O 149:K91(B) 90.7% of the P.W.D. strains and 47.6% of the N.C.D. strains produced colicins (Table V). The impairment of these features in the pathogenesis of neonatal E. coli diarrhoea, post weaning diarrhoea and the possible causality of the domination of the serogroup O 149:K91(B) is discussed. Furthermore it seems justified to relate the syndrome designation to the serotype of porcine enteropathogenic E. coli strains as it will be difficult to compare strains described from different research workers.
Nord Vet Med 1976 Sep
PMID:Differences between enteropathogenic Escherichia coli strains isolated from neonatal E. coli diarrhoea (N.C.D.) and post weaning diarrhoea (P.W.D.) in pigs. 79 Mar 6

One hundred forty-eight drugs and other organic and inorganic substances were screened for their ability to inhibit the enzyme urease in an in vitro system modeled on infected urine. The reported urease-inhibiting properties of ascorbic acid, tetracyclines, and sulfanilamide were not confirmed. At least 50 per cent inhibition was observed in the presence of kanamvcin, hydroxguanidine, benzoquinone, 1,2-naphthaquinone-4-sulfonate, chloramine-T, N-bromoacetamide, copper, mercury, and fluoride. It is, however, unlikely that therapeutically effective concentrations can be attained in urine without giving dosages likely to result in toxic effects. Hydroxyurea, at the dose level used in cytotoxic therapy, may be expected to produce effective inhibition of bacterial urease in the urinary tract, providing renal function is unimpaired and providing urinary volume does not exceed 1 liter per 24 hr. Acetohydroxamic acid is potentially the most useful drug for the treatment of infection-induced urinary stone disease available at present.
Invest Urol 1977 Sep
PMID:Inhibition of urease by miscellaneous ions and compounds. Implications for the therapy of infection-induced urolithiasis. 90 16


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