Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The antifungal antibiotic flavensomycin inhibited the oxidation of amino acids and of glucose by Penicillium oxalicum. The compound inhibited l-amino acid oxidase (EC 1.4.3.2) activity for l-leucine and l-phenylalanine, and also d-amino acid oxidase (EC 1.4.3.3) in the oxidation for dl-alanine. The addition of flavin adenine dinucleotide, which is a cofactor for this enzyme, antagonized the action of the antibiotic. Glucose oxidase (EC 1.1.3.4) was also inhibited. The antibiotic inhibited the reduced nicotinamide adenine dinucleotide (NADH(2)) cytochrome c reductase (EC 1.6.2.1) as well as the much slower nonenzymatic reduction of this cytochrome by the nucleotide. Reduced cytochrome c was also oxidized nonenzymatically by flavensomycin. The antibiotic completely inhibited the action of rabbit muscle lactic dehydrogenase (EC 1.1.1.27) in promoting the reduction of pyruvate by NADH(2) but only slightly affected the reverse reaction. Alcohol dehydrogenase (EC 1.1.1.1) was also similarly inhibited. Flavensomycin prevented the reduction of nicotinamide adenine dinucleotide phosphate by isocitrate in the presence of isocitrate dehydrogenase (EC 1.1.1.42). The hexokinase (EC 2.7.1.1)-catalyzed phosphorylation of glucose, in which the adenosine triphosphate acts as a phosphate donor, was only slightly affected. Flavensomycin also inhibited the action of yeast lactate dehydrogenase (EC 1.1.2.3) on the reduction of cytochrome c. High concentrations of cytochrome c were antagonistic to this reaction. The results point to an interference with enzymatically controlled hydrogen or electron transfer as the mechanism of the antifungal activity of flavensomycin.
 ...
PMID:Flavensomycin, an inhibitor of enzyme reactions involving hydrogen transfer. 438 33

Two enzymatic assay procedures for the measurement of 2,5-anhydrohexitol fructose analogs have been devised. Both procedures are based on the measurement of ADP formed during enzymatic phosphorylation of the analogs either by hexokinase or by fructokinase. The actual measurement makes use of the coupled assay system using pyruvate kinase, PEP, lactate dehydrogenase, and NADH. Both systems can be used to measure fructose and appropriate analogs at cuvette concentrations up to 0.10 mM. The hexokinase procedures allows the measurement of fructose, 2,5-anhydromannitol, and 2,5-anhydromannose. Glucose, which also reacts, can be removed by pretreatment of the samples with glucose oxidase. The fructokinase procedure allows the measurement of fructose, 2,5-anhydromannitol, 2,5-anhydroglucitol, and 2,5-anhydrotalitol.
 ...
PMID:Enzymatic analysis of 2,5-anhydro-D-mannitol and related compounds. 641 7

Collection of blood spots on filter paper offers a practical alternative for home monitoring of diabetic patients. We have compared the merits of three protein precipitants, trichloracetic acid (TCA), perchloric acid (PCA) and sulphosalicylic acid (SSA) for the elution of glucose from the filter paper, and their subsequent effects on three enzymic methods, glucose dehydrogenase (GDH), hexokinase (HK), and glucose oxidase (GOD) for the determination of glucose using a microcentrifugal analyser. The combination of TCA elutant with the GDH method was superior with respect to time course of reaction and elution time from the filter paper, and was chosen for routine use. Within- and between-batch precision for this method was 2.7% and 3.2% respectively at normal glucose concentrations. Recovery of glucose added to whole blood was 110 +/- 5%. Comparison with an automated glucose oxidase method for plasma glucose gave a slope of 1.1, intercept of -0.7 and a correlation coefficient of 0.9 (n = 64). We conclude that the combination of TCA and glucose dehydrogenase provides a robust, precise and accurate method for the quantitation of glucose in filter-paper blood spots. The procedure offers increased sensitivity and better precision than GOD methods. The use of TCA as elutant gives a faster elution time and has the least effect on any of the enzymic methods.
 ...
PMID:Performance of three enzymic methods for filter paper glucose determination. 650 12

A new and simple enzymatic assay for measuring D-mannose in serum is described. Endogenous glucose is eliminated from serum by use of glucose oxidase (EC 1.1.3.4) and catalase (EC 1.11.1.6). D-Mannose concentration is calculated from the increase in NADH formation after mannosephosphate isomerase (EC 5.3.1.8) is added. This increase is a result of coupling the following series of enzymes: hexokinase (EC 2.7.1.1), glucosephosphate isomerase (EC 5.3.1.9), and glucose-6-phosphate dehydrogenase (EC 1.1.1.49, NAD+-dependent). The study included subjects who were healthy volunteers and patients with suspected or proven fungal infections.
 ...
PMID:Enzymatic determination of D-mannose in serum. 669 39

Serum from patients was pooled, filtered, dispensed, and frozen. This pooled specimen was used for accuracy control in 64 participating laboratories in Sweden. Mean values ("state-of-the-art" values) were obtained for creatinine, cholesterol, glucose, urea, uric acid, and cortisol. These values were compared with values obtained with highly accurate reference methods based on isotope dilution-mass spectrometry. Differences were marked in the case of determination of creatinine and cortisol. Concerning the other components, the differences between the state-of-the-art value and the values obtained with the reference methods were negligible. Moreover, the glucose oxidase and the oxime methods for determination of glucose and urea were found to give significantly lower values than the hexokinase and urease methods, respectively. We conclude that methods with a higher degree of accuracy are required for routine determination of creatinine and cortisol.
 ...
PMID:Accuracy of some routine method used in clinical chemistry as judged by isotope dilution-mass spectrometry. 701 32

Glucose was measured by the ferricyanide, the Beckman glucose oxidase, and the hexokinase procedures in 228 plasma samples taken during standard oral glucose-tolerance tests in 17 normal subjects and in 21 chemical diabetics. The neocuproine method was also used to measure glucose concentration in 156 samples (78 before and 78 after dialysis) collected from six diabetic and uremic patients who were on maintenance hemodialysis. Ferricyanide in all conditions and neocuproine in uremic patients overestimated glucose concentrations over the entire experimental range as compared with either enzymic method. This bias or systematic error of the reducing vs the enzymic procedures, due to nonglucose reducing substances ("saccharoids"), becomes considerably greater when their concentration is increased as in chronic uremia. Also, the inverse relation between glucose concentration and overestimation of glucose by the reducing methods has been detected. With respect to the hexokinase method, a mild but significant underestimate of glucose oxidase readings has been observed for higher glucose concentrations. We find neocuproine to be the most imprecise of these procedures.
 ...
PMID:Four methods for glucose assay compared for various glucose concentrations and under different clinical conditions. 713 20

A method for the determination of glucose is described. H2O2, produced by the action of glucose oxidase, is measured from the change in absorbance due to oxidation of NAD(P)H in the presence of catalase, aldehyde dehydrogenase and a high concentration of ethanol. The quality data of the method are equivalent to those of the hexokinase-glucose-6-phosphate dehydrogenase method used as reference.
 ...
PMID:A new enzymatic method for the determination of glucose. 728 78

The ELITE glucometer (Bayer Diagnostics), which uses a glucose oxidase sensor coupled to an amperometric measurement, was compared with the routine hexokinase method on the EPOS (Eppendorf--Netheler-Hinz) using commercially available reagents (Boehringer-Mannheim). Both methods were carried out using whole blood as sample. The comparison was made under routine conditions on 106 non-selected patients from whom a glucose determination had been requested. The results gave rise to a correlation coefficient of 0.986 with the regression equation: GlucoseELITE = 1.04 x GlucoseEPOS -0.201 mmol/l. Deviations between both methods were seen, although these had little or no clinical relevance. A positive deviation in favour of the ELITE was seen in a blood sample with 21.8 mmol/l glucose (EPOS) and 1025 mumol/l uric acid. A negative deviation, with respect to the ELITE, was seen in a blood sample with 3.00 mmol/l glucose (EPOS). Blood ethanol concentration up to 0.1 mol/l and uric acid concentrations up to 450 mumol/l did not directly influence the ELITE method. The intra-assay coefficient of variation of the ELITE glucometer was 5.3% at 4.95 mmol/l and 3.1% at 15.2 mmol/l. The corresponding inter-assay coefficients of variation were 6.8% at 5.14 mmol/l and 3.90% at 15.4 mmol/l. Both sets of results were derived from 20 measurements made consecutively or on 20 consecutive days. The ELITE glucometer proved to be a hygienic and practical alternative for on-site measurement of blood glucose and gave results comparable with those using the routine hexokinase method with haemolysed capillary blood.
 ...
PMID:Comparison between the Bayer ELITE glucometer and the hexokinase method for glucose determination on the Eppendorf EPOS 5060 using capillary whole blood samples. 760 28

A chemiluminescence fiber optic system coupled to flow injection analysis (FIA) and ion exchange chromatography has been developed for determining glucose in blood and urine. Immobilized glucose oxidase acted on beta-D-glucose to produce hydrogen peroxide, which was then reacted with luminol in the presence of ferricyanide to produce a light signal. Endogenous ascorbic acid and uric acid present in urine or blood samples were effectively retained by an upstream acetate anion exchanger. In addition, acetaminophen could also be adsorbed by this ion exchanger. The detection system exhibited a sensitivity of 1.315 +/- 0.044 RU microM-1 for glucose with a minimum detection level of 1 microM. When applied for the determination of urinary and blood glucose levels, the results obtained compared well with those of the reference hexokinase assay. Immobilized glucose oxidase was reused for over 500 analyses without losing its original activity. A conservative estimate for the reuse of the acetate ion exchange column was about 100 analyses.
 ...
PMID:On-line chemiluminescence assay using FIA and fiber optics for urinary and blood glucose. 776 30

Glucose oxidase with ferricyan ion (GOD-F) is widely applied in clinical settings as a glucose sensor. However, blood oxygen concentration affects this blood glucose value because oxygen, at increased concentrations, consumes blood glucose, which cannot then be measured by this sensor. We investigated the effect of PO2 on blood glucose concentration in 48 patients who were breathing high concentrations of oxygen. Arterial and pulmonary arterial blood glucose values were analyzed using the GOD-F method and, as a control, the hexokinase method. The respective PO2 values were also measured. The blood glucose concentrations measured by the GOD-F method show a significant linear relation with that measured by the hexokinase method in both arterial (y = -24.4 + 1.01x, r = 0.99) and pulmonary arterial blood (y = -3.4 + 1.01x, r = 0.96). The difference of intercepts is statistically significant, but because of the relatively large limits of agreement indicating any hidden extraneous variabilities, the error of the GOD-F method could not be assessed just by the difference. The equation defining the effect of PO2 on the percent change between blood glucose measured by the GOD-F method and that measured by the hexokinase method is -19.8/(1 + 203900/PO2(2.68) (r = 0.62). This formula generally follows our measured materials and introduces the relationship among blood glucose value, PO2, and the error of the GOD-F method. We hesitate to suggest that the arterial blood glucose concentration when measured by the GOD-F method could be underestimated by as much as 20% in patients with high arterial oxygen pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The effect of the partial pressure of oxygen on blood glucose concentration examined using glucose oxidase with ferricyan ion. 797 22


<< Previous 1 2 3 4 5 6 7 8 Next >>