Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some properties of a number of enzymes immobilized by the diazotized m-diaminobenzene (dDAB) method are described. The pH-activity profiles of beta-D-glucosidase, glucoamylase, peroxidase, uricase, and D-glucose oxidase were virtually unchanged on immobilization while those of catalase and dextranase were significantly altered. beta-D-Glucosidase, glucoamylase, and glucose oxidase were found to be more susceptible to denaturation on lyophilization when immobilized than in the native state; however, sorbitol had a marked protective effect in every case examined. Sorbitol was also found to exert a stabilizing effect when lyophilized immobilized preparations were stored. Immobilization marginally improved the stabilities of a number of enzymes to heating at 60 degrees at pH 8.0. The usefulness for continuous reaction of a column of glucoamylase attached to celite was established. The reuse of the solid supports was demonstrated.
 ...
PMID:Properties of enzymes immobilized by the diazotized m-diaminobenzene method. 1 49

The authors describe an automatic method of estimation of uric acid based on the colour obtained in the presence of Gaiac resin and peroxidase, and the hydrogen peroxide produced by the action of urate oxidase on uric acid.
 ...
PMID:[Automatic dosage of uric acid by urate oxydase. Comparison with Praetorius' methods]. 24 Dec 80

A novel fluorometric method for the determination of uric acid based on the coupled reactions of uric acid with uricase and peroxidase to form highly fluorescent 2,2'dihydroxy-3,3'-dimethoxy-biphenyl-5,5'-diacetic acid is described. The calibration curve was constructed from a series of standard uric acid solutions vs. the corresponding relative fluorescence. It was linear up to 15 mg/dl (0.9 mmol/l). The serum or plasma samples must be deproteinated with (absolute) ethanol before assay and its uric acid content can be obtained from the calibration curve. This method is rather simple, having good precision and accuracy. High level ascorbic acid in the sample falsely elevates uric acid concentration. Comparison of the results obtained on the patient sera with a colorimetric phosphotungstate method and a standard enzymatic spectrophotometric method gave coefficients of correlation of 0.908 and 0.986, respectively.
 ...
PMID:An alternative method for the determination of uric acid in serum. 24 14

We studied the use of immobilized enzymes, covalently bound to alkylaminosilane derivative of porous glass, to automated clinical analysis on uric acid and glucose in blood, serum and urine. A microcolumn with an immobilized enzyme was prepared and used in an AutoAnalyzer I continuous flow system. Uricase (EC 1.7.3.3) from Candida utilis and glucose oxidase (EC 1.1.3.4) from Aspergillus niger were immobilized for the determination of uric acid and glucose, respectively. Hydrogen peroxide produced by these oxidases was colorimetrically determined using horse-radish peroxidase (EC 1.11.1.7) and a hydrogen acceptor in solution. Sensitivity and wash charactertistics of a column with immobilized enzyme, 1.5 mm of inner diameter and up to 40 mm in length, were satisfactory at an assay speed of 50 samples per hour. The results correlated well with those obtained by other well established methods utilizing the AutoAnalyzer system. The immobilized enzymes were sufficiently stable for at least two months of 2000 tests when used repeatedly. Clinical trials proved that this method is capable of replacing the soluble enzyme method, giving reliable and reproducible results at lower cost.
 ...
PMID:Use of immobilized enzymes in automated clinical analysis: determination of uric acid and glucose using immobilized enzymes in column form. 52 27

A method was developed to determine the total content of the oxypurines, xanthine and hypoxanthine, in animal tissues. The developed method was constructed mainly from the following successive steps: (1) conversion of the oxypurines to uric acid and hydrogen peroxidase by xanthine oxidase; (2) decomposition of the hydrogen peroxide by catalase and subsequent inactivation of this enzyme; (3) fluorometric measurement of the uric acid based on the coupled enzyme reaction of uricase and peroxidase. In applying this method to a sample containing uric acid, preliminary removal of this uric acid was necessary and this was carried out by treating the sample with uricase, followed by subsequent inactivation of this enzyme. The present method was more specific than the existing fluorometric method and permitted to measure the total content of the oxypurines (as low as 1 nmol) without mutual separation of them. The actual application of this method to the rat liver was demonstrated together with the method to prepare the tissue sample for the assay.
 ...
PMID:Fluorometric determination of xanthine and hypoxanthine in tissue. 58 29

This report describes a new specific colorimetric procedure for uric acid assay with AutoAnalyzer II and SMA (Technicon) systems, made specific by the application of uricase. Hydrogen preroxide, formed in this reaction, effects the oxidative coupling of 4-aminophenazone and 2,4-dichlorophenol under the catalytic influence of peroxidase. The red dye formed is measured at 505 or 520 nm. A sample blank measurement is not necessary, and the reagents show very good stability. The test shows linearity up to 714 mumol of uric acid per liter. Results of thie method correlate very well with those by the uricase-ultraviolet and uricase--catalase methods. There is no interference by hemoglobin, bilirubin, lipemia, and various drugs, except a minor interference by alpha-methyldopa. Interference from ascorbate is eliminated by ascorbate oxidase. This method can be regarded as a considerably improved routine test for uric acid on continuous-flow systems in clinical laboratories as compared with the commonly used phosphotungstate method.
 ...
PMID:Determination of uric acid on continuous-flow (AutoAnalyzer II and SMA) systems with a uricase/phenol/4-aminophenazone color test. 62 57

We describe the enzymatic determination of uric acid (uricase/peroxidase) with the SMAC system. The method correlates well with known SMA 12 and Autoanalyzer methods. The change from the original uric acid method to the enzymatic one is simple and does not require any change of the software.
 ...
PMID:[Adaptation of the SMAC for the determination of uric acid with an uricase/perioxidase procedure (author's transl)]. 64 55

We report here the preparation of an immobilized-enzyme nylon-tube reactor containing uricase (EC 1.7.3.3) and the assembly of a flow-through system (Technicon AutoAnalyzer II) for the routine determination of uric acid in serum. Results of these uric acid analyses by use of immobilized uricase, in conjunction with peroxidase (EC 1.11.1.7) and aminophenazone-dichlorophenol in solution, are compared with those obtained with the same enzyme in solution by use of the uricase-PAP (peroxidase, 4-aminophenazone, dichlorophenol) method. Clinical trials carried out routinely with the uricase reactor give reliable and reproducible results with high precision at an appreciably lower cost. The reactors are stable to continued or intermittent use for at least three months or for 4000 tests.
 ...
PMID:Immobilized-enzyme nylon-tube reactor for routine determination of uric acid in serum. 69 91

We describe a manual method, well suited to mechanization, for quantitating serum uric acid at 500 nm. In the assay mixture (0.10 ml of sample and 3.00 ml of reagent) the hydrogen peroxide produced from uric acid by uricase is coupled with p-hydroxybenzoate and 4-aminoantipyrine in the presence of peroxidase to form a colored complex, which is measured. A separate sample blank is obviated by taking an initial absorbance measurement 20 s after the sample is added. The reaction is complete within 5 min; its sensitivity is 0.001 deltaA/mg per liter. Absorbances are linearly related to uric acid concentrations up to 120 mg/liter. Many substances that may be present in normal serum do not interfere, but bilirubin in moderately above-normal concentrations will interfere. The procedure can be modified to largely correct for this, when necessary. The proposed method (y) correlated well (r = 0.979) with the uric acid 293 nm reference method (x) and the relation is described by the equation y = 0.998x + 2.42.
 ...
PMID:New enzymatic method for serum uric acid at 500 nm. 70 18

We describe the automated microassay of plasma uric acid by use of an immobilized uricase-membrane sandwich reactor. Hydrogen peroxide, formed when uric acid is oxidized, oxidatively couples two molecules of p-hydroxyphenylacetic acid in the presence of peroxidase to produce a highly fluorescent compound. The specificity of the uricase reaction is coupled with a significantly lower cost of analysis.
 ...
PMID:Immobilized-enzyme membrane sandwich reactor used in automated micro-scale assay of plasma uric acid. 70 42


1 2 3 4 5 6 7 8 9 10 Next >>