Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A modification of a kinetic determination of 5'-nucleotidase (EC 3.1.3.5) activity is described. Special attention has been paid to the stabilisation of glutamate dehydrogenase (EC 1.4.1.2) by L-leucine, optimal NADH concentration and the influence of endogeneous ammonia. The optimal concentrations of the other constituents of the reagent were checked with the optimal values given in the literature. Normal values were determined. The proposed method shows a good correlation with a colorimetric reference method.
 ...
PMID:A kinetic method for serum 5'-nucleotidase using stabilised glutamate dehydrogenase. 18 Feb 32

A semi-automated method for determining the 5'-nucleotidase activity in human serum for use with the Technicon Autoanalyzer I is described. Based upon the manual method of Persijn and Van Der Slik, adenosine formed by hydrolysis of 5'-AMP is deamined enzymatically and ammonia determined with the Berthelot reaction. The non specific alkaline phosphatases are inhibited by phenylphosphate. Concentrations of 5'-AMP and phenylphosphate are discussed. Nucleotidase activity is determined without dilution up to a value of 210 UI/liter. The precision is better than other manual or semi-automated methods in current use.
 ...
PMID:[Semiautomatic method of measurement of serum 5'nucleotidase activity]. 24 42

Concanavalin A inhibits serum 5'-nucleotidase activity, without causing significant inhibition of alkaline phosphatase activity. This observation serves as the basis for a new method for assaying the 5'-nucleotidase activity in serum, which depends upon the difference between the enzymic hydrolysis of adenosine-5'-monophosphate in the presence and absence of concanavalin A. A denosine released by the 5'-nucleotidase reaction is deaminated by a coupled reaction with adenosine deaminase to liberate inosine and ammonia, and ammonia is measured colorimetrically by the Berthelot reaction. In sera from 40 healthy adult persons, 5'-nucleotidase activity averaged 6.4 U/liter (SD, +/-2.0; range, 3-12). In sera from 100 patients, measurements of 5'-nucleotidase activity by the new assay averaged 8% lower than by a generally accepted method in which phenyl phosphate is used to suppress hydrolysis of adenosine-5'-monophosphate by alkaline phosphatase activity. The clinical validy of the new assay was tested by measuring serum 5'-nucleotidase activities in rats with bile duct ligation and in rats treated with thioacetamide to induce hepatocellular injury.
 ...
PMID:Inhibition by concanavalin A as the basis for a specific assay of serum 5'-nucleotidase activity. 92 81

Serum mucleotidase activity (EC 3.1.3.5) is measured by the amount of ammonia liberated from cytidine after incubation with cytidine deaminase (EC 3.5 4.5). Purification of the cytidine deaminase results in the abolition of interfering reactions, so that routine application is possible.
 ...
PMID:Determination of serum nucleotidase with cytidine monophosphate as substrate. Part II: Improvement of the procedure. 99 32

This paper deals with a new method for the determination of serum nucleotidase (EC 3.1.3.5). The assay is performed with cytidine-5'-monophosphate as substrate, followed by deamination of the generated cytidine. The principle of the method and the determination of the liberated ammonia by the Berthelot indophenol-reaction are comparable to the Persijn--van der Slik method in which adenosine-5'-monophosphate is used as substrate. The correlation between the results obtained with these two methods was found to be good; the new method has the advantage of higher sensitivity.
 ...
PMID:Determination of serum nucleotidase with cytidine monophosphate as substrate, (I). 109 94

The activities (Vmax) of several enzymes of purine nucleotide metabolism were assayed in premature and mature primary rat neuronal cultures and in whole rat brains. In the neuronal cultures, representing 90% pure neurons, maturation (up to 14 days in culture) resulted in an increase in the activities of guanine deaminase (guanase), purine-nucleoside phosphorylase (PNP), IMP 5'-nucleotidase, adenine phosphoribosyltransferase (APRT), and AMP deaminase, but in no change in the activities of hypoxanthine-guanine phosphoribosyltransferase (HGPRT), adenosine deaminase, adenosine kinase, and AMP 5'-nucleotidase. In whole brains in vivo, maturation (from 18 days of gestation to 14 days post partum) was associated with an increase in the activities of guanase, PNP, IMP 5'-nucleotidase, AMP deaminase, and HGPRT, a decrease in the activities of adenosine deaminase and IMP dehydrogenase, and no change in the activities of APRT, AMP 5'-nucleotidase, and adenosine kinase. The profound changes in purine metabolism, which occur with maturation of the neuronal cells in primary cultures in vitro and in whole brains in vivo, create an advantage for AMP degradation by deamination, rather than by dephosphorylation, and for guanine degradation to xanthine over its reutilization for synthesis of GMP. The physiological meaning of the maturational increase in these two ammonia-producing enzymes in the brain is not yet clear. The striking similarity in the alterations of enzyme activities in the two systems indicates that the primary culture system may serve as an appropriate model for the study of purine metabolism in brain.
 ...
PMID:Developmental changes in the activity of enzymes of purine metabolism in rat neuronal cells in culture and in whole brain. 232 47

A reliable assay was developed to characterize crude cell homogenates with regard to their adenine phosphoribosyltransferase activities. The 5-phosphoribosyl-1-pyrophosphate (PRPP)-dependent formation of AMP from adenine is followed spectrophotometrically at 265 nm by coupling it with the following two-stage enzymatic conversion: AMP + H2O----adenosine + Pi (5'-nucleotidase); adenosine + H2O----inosine + NH3 (adenosine deaminase). The same principle was applied to develop a spectrophotometric and a radioenzymatic assay for PRPP. The basis of the spectrophotometric assay is the absorbance change at 265 nm associated with the enzymatic conversion of PRPP into inosine, catalyzed by the sequential action of partially purified adenine phosphoribosyltransferase, commercial 5'-nucleotidase, and commercial adenosine deaminase, in the presence of excess adenine. In the radiochemical assay PRPP is quantitatively converted into [14C]inosine via the same combined reaction. Tissue extracts are incubated with excess [14C]adenine. The radioactivity of inosine, separated by a thin-layer chromatographic system, is a measure of PRPP present in tissue extracts. The radioenzymatic assay is at least as sensitive as other methods based on the use of adenine phosphoribosyltransferase. However, it overcomes the reversibility of the reaction and the need to use transferase preparations free of any phosphatase and adenosine deaminase activities.
 ...
PMID:A coupled optical assay for adenine phosphoribosyltransferase and its extension for the spectrophotometric and radioenzymatic determination of 5-phosphoribosyl-1-pyrophosphate in mixtures and in tissue extracts. 244 24

Corynebacterium glutamicum cells are industrially used for glutamate production. However, the waste that contains microbial cells, cellular debris, residual sugars, ammonia and metabolites seriously pollutes the environment. The cells are recovered and utilized for ribonucleotide production so that the pollution caused by the cells is eliminated. Nucleic acid is extracted from the cells and is hydrolyzed with nuclease P1 from Penicillium citrinum. The hydrolysate is fractionated with Dowex-50 and Dowex-1 into 5'-CMP, 5'-UMP, 5'-GMP and 5'-AMP. The products are characterized by electrophoresis, ultraviolet light absorbance, and 5'-nucleotidase.
 ...
PMID:Utilization of glutamate accumulating bacterial cells for production of ribonucleotides. 303 25

A rapid, simple, quantitative and sensitive assay for the determination of 5'-nucleotidase has been developed. The method can be applied to both soluble and membrane bound forms of the leukocyte enzyme. Enzyme activity is determined by colorimetric estimation of NH3 released from adenosine, the product of 5'-nucleotidase activity in the presence of adenosine deaminase. The assay may be performed in microtitre plates and read with an automatic multiscan spectrophotometer. Thus it can be applied to a large number of samples for routine medical and research purposes.
 ...
PMID:A colorimetric assay for the determination of 5'-nucleotidase activity. 303 4

Hepatic function can be monitored using exogenous (e.g., sulfobromophthalein, indocyanine green, antipyrine, aminopyrine, galactose) and endogenous substances (e.g., bile acids, PT/PTT, albumin, ammonia, bilirubin). Test of hepatic necrosis include aspartate aminotransferase, and alanine aminotransferase. The hepatobiliary system can be assessed using alkaline phosphatase, 5'-nucleotidase, gamma-glutamyl transpeptidase, ultrasound, and iminodiacetic acid scans.
 ...
PMID:Monitoring hepatic function. 306 53


1 2 Next >>