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

A method is described for isolation of gram quantities of the components of the streptothricin complex S15-1 utilizing CM Sephadex column chromatography eluted with 10% acetic acid as an eluant followed by gradient elution with 10% acetic acid containing 0.02 N approximately 0.03 N HCI. Streptothricins F and E, as well as an unidentified component C1, have been isolated and their comparative biological activities determined. Streptothricins F and E were comparable in taeniacidal activity in mice infected with Hymenolepis nana ia feeding either one at 0.05% in the diet removed 92 approximately 100% of the adult tapeworms. The unidentified component C1 was inactive at the levels tested. In contrast, component C1 was the most active in antimicrobial activity against Bacillus subtilis and in inhibiting the urease activity of proteus mirabilis. In the former test, the ratios of activity were; 1:7:30 for F:E:C1 and in the latter; 1:2:4 for F:E:C1.
 ...
PMID:Separation and biologic activities of individual components of S15-1, a streptothricin class antibiotic. 626 89

We describe a coupled-enzyme equilibrium method for measuring urea in serum, which is performed on supernates prepared by treating each specimen with Ba(OH)2 and ZnSO4 (Somogyi reagent). Analytical recovery of [14C]urea added to a variety of matrices was essentially complete (mean, 100.6%) for the supernates after precipitation. Nine variables were univariately examined in arriving at the reaction conditions for the method: glutamate dehydrogenase, urease, 2-oxoglutarate, ADP, Tris . HCI, NADH, EDTA, pH, and temperature. The reagent is stable for at least 48 days at--20 degrees C and for 23 days at 4 degrees C. Mean analytical recovery of urea (14 mmol/L) added to seven different specimens (three different matrices) was 100.8%. The analytical linear range of the method extends to 30 mmol of urea per liter. Of 22 potential interferents, only bilirubin at 1 mmol/L (580 mg/L), hemoglobin at 10 g/L, and hydroxyurea at 6 mmol/L showed more than 2% interference. We discuss precision and effects of specimen dilution, and compare results for 100 human serum specimens with those measured for the same specimens with four other urea methods. We examined the effects of measuring a blank, consisting of sample and reagent without urease, with each specimen.
 ...
PMID:A coupled-enzyme equilibrium method for measuring urea in serum: optimization and evaluation of the AACC study group on urea candidate reference method. 737 2

Enzymatic electrode for a potentiometric urea sensor was prepared by sequential coating of carbon nanotube (CNT), urease (Urs) and polyion complex (mixture of poly-L-lysine hydrobromide and poly (sodium 4-styrenesulfonate), PIC) on an ITO glass. The prepared electrode (ITO/CNT/Urs/PIC) was characterized by potentiometric measurements at different urea concentrations in Tris-HCI buffer (pH 7.0). The potentiometric response of the electrode was linear in the range of 1 x 10(-5) to 3 x 10(-3) M with a correlation coefficient of 0.999 and a sensitivity of 59.1 mV/decade. It was found that the addition of CNT caused considerable improvement of the sensitivity of the electrode to urea. The response time was approximately 60-90 s. A half of the initial sensitivity was retained for 15-17 d at room temperature.
 ...
PMID:Potentiometric Urea Biosensor Based on Carbon Nanotubes and Polyion Complex Film. 2635 25