Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.5 (urease)
 7,257 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The possibility to keep some biochemical reactions of the parent strains (urease-positive, glucose fermentation, phenylalanine-deaminase-positive, H2S but not indol production) was demonstrated in 5 L-forms, obtained from as many strains of Pr. mirabilis and in 1 L-form, isolated from a vaginal secretion and identified as belonging to the same species. The indirect hemagglutination technique, made by the sonicated antigen in 3 of the 6 L-forms with Proteus OXK antiserum, resulted positive in titers varying from 1:128 to 1:1024. Crossed tests made with antisera for different bacterial species (e. coli, Shigella, klebsiella, ecc.) and of Mycoplasma (M. hominis, M. orale, M. salivarium, M. fermentans, M. arthritidis) put in evidence aspecific reactions only in 1.3% of the bacterial antisera. On the contrary, all 5 antisera for Mycoplasma were able to agglutinate the sensitized erythrocytes at titers quite analogous to that of the homologous antiserum. The sensitivities to various antibiotics of the 6 L-forms and the parent strains has been determined. All of L-forms were more resistent to the tetracycline than L-forms of other bacterial species. On the basis of te results got by biochemical and serological tests, we confirm the necessity to make use of both the groups of tests, in order to identify the L-forms of recent isolation.
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PMID:[Researches on some biochemical and serological properties and on the sensitivity to antibiotics of L-forms of "Proteus" (author's transl)]. 40 87

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.
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PMID:Active water-insoluble derivatives of papain and other enzymes based on preformed diazonium-type supports. 40 36

Pseudomonas aeruginosa AI 3 was able to grow in medium containing acetanilide (N-phenylacetamide) as a carbon source when NH4+ was the nitrogen source but not when urea was the nitrogen source. AIU mutants isolated from strain AI 3 grew on either medium. Urease levels in bacteria grown in the presence of urea were 10-fold lower when NH4+ or acetanilide was also in the medium, but there were no apparent differences in urease or its synthesis between strain AI 3 and mutant AIU 1N. The first metabolic step in the acetanilide utlization is catalyzed by an amidase. Amidases in several AIU strains showed altered physiochemical properties. Urea inhibited amidase in a time-dependent reaction, but the rates of the inhibitory reaction with amidases from the AIU mutants were slower than with AI 3 amidase. The purified amidase from AIU 1N showed a marked difference in its pH/activity profile from that obtained with purified AI 3 amidase. These observations indicate that the ability of strain AIU 1N and the other mutants to grow on acetanilide/urea medium is associated with a mutation in the amidase structural gene; this was confirmed for strain AIU 1N by transduction.
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PMID:Pseudomonas aeruginosa mutants resistant to urea inhibition of growth on acetanilide. 41 Jul 88

The isolation, characterization, and identification of a microorganism isolated from gastrointestinal tracts of rabbits with mucoid enteritis are described. The isolated organism did not grow on standard media. This organism grew around colonies of Staphylococcus aureus and Lactobacillus desidiosus and around disks saturated with diphosphopyridin nucleotide (factor V) on brain heart infusion agar. The growth of this organism was also observed on media supplemented with beta-nicotinamide adenine dinucleotide. The organism appeared as gram-negative, pleomorphic rods or coccobacilli. It was positive for urease, oxidase, catalase, glycosidases, porphyrin, and indole, and it fermented glucose and sucrose. All of these characteristics suggest that the organism is a member of the genus Haemophilus. Because of its isolation from rabbits and differences in some characteristics from other species of this genus, the name Haemophilus paracuniculus is proposed for this organism.
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PMID:Characterization of a Haemophilus paracuniculus isolated from gastrointestinal tracts of rabbits with mucoid enteritis. 42 39

A microencapsulated multienzyme system containing urease, glutamate dehydrogenase and glucose dehydrogenase has been used to convert urea and ammonia into an amino acid. The effect of two different glucose dehydrogenases was studied in detail. High-specific-activity glucose dehydrogenase requires minimal cofactor and glucose and can greatly facilitate the further development of this approach for possible clinical applications.
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PMID:Effects of glucose dehydrogenase in converting urea and ammonia into amino acid using artificial cells. 43 22

A large radiodense calculus in the left renal pelvis of a 22-month-old, male Great Dane disappeared one month following surgical removal of two struvite (magnesium ammonium phosphate) calculi from the right renal pelvis. The dog's urine likely became undersaturated with struvite for a sufficient period to permit dissolution of the renal calculus. Several factors may have contributed to the decrease in urine struvite concentration, including eradication of a urease-producing Proteus sp from the urinary tract and induction of polydipsia and compensatory polyuria by oral administration of sodium chloride.
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PMID:Dissolution of a struvite nephrolith in a dog. 43 42

A novel approach is reported for the removal of ammonium formed from the conversion of urea by urease. By alkalinization, ammonium is converted into free ammonia. Free ammonia can then be very easily removed by a number of approaches: as gaseous ammonia by air bubbling, oxygenator, or air ventilation; by adsorbent for free ammonia; or other approaches.
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PMID:Urea and ammonium removal based on alkalinization and removal of free ammonia. 45 5

Bacteria induce urinary crystallization of struvite and carbonate-apatite as a by-product of ureolysis by urease. Eradication of infection and/or inhibition of urease with acetohydroxamic acid for 5 to 30 months retarded stone growth and brought about partial or comple dissolution of stones in 9 patients. Long-term chemotherapy with antimicrobial agents that achieve steril urine or acetohydroxamic acid in those patients with recalcitrant infection lessens the risk of recurrent calculogenesis.
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PMID:Adjunctive chemotherapy of infection-induced staghorn calculi. 45 40

A simple device, consisting of a heat sensor placed in close contact to fibres containing enzymes and connected to a temperature measuring unit has been developed. The system monitors the temperature variations due to the enzymatic reaction when substrate solutions flow through the measuring cell. Fibres containing the enzymes glucose oxidase and catalase for the determination of glucose and fibres containing urease for the determination of urea were tested. A linear relationship between the substrate concentration and the deltaT recorded was obtained in both cases.
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PMID:Monitoring of metabolites applying fibre-entrapped enzymes in a calorimetric system. I -- Glucose and urea determination. 46 7

We describe a fixed-time-interval, kinetic inhibition method, with use of a competitive inhibitor (l) of the urease/glutamate dehydrogenase reaction to increase the "apparent" Michaelis constant by a factor of (1 + [l]lKl). This allows greater flexibility in selecting an appropriate sample dilution for kinetic determinations of urea in serum (i.e., [S]lKm ratio). Nine compounds were screened as potential inhibitors for this study. Adding 5 mmol of hydroxyurea per liter increases the "apparent" Michaelis constant for the coupled enzyme reaction by 10-fold. We used a sample dilution of 21-fold vs. dilutions of 141- to 350-fold for previously reported kinetic methods. Mean analytical recovery with this method was 100.2%. Reaction rate vs. urea concentration was linear, and complete recovery extended to 30 mmol of urea per liter. Of 22 potential interferents, only fluoride (250 mmol/L) and bilirubin (1 mmol/L, or 580 mg/L) caused greater than 5% interference. We discuss precision and effects of specimen dilution, and compare results for 100 specimens with those by a manual Berthelot-indophenol method, a manual diacetyl monoxime method, and a diacetyl monoxime method adapted to continuous-flow analysis.
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PMID:Chemical inhibition used in a kinetic urease/glutamate dehydrogenase method for urea in serum. 47 21


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