Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.1.1 (hexokinase)
5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reflection confocal microscopy was used to determine the intracellular distribution of Type I and III isozymes of hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1) in PC12 cells; detection was by staining with diaminobenzidine as a substrate for horseradish peroxidase-conjugated antimouse immunoglobulins bound to isozyme-specific monoclonal antibodies. With both isozymes, detection of the staining pattern was significantly enhanced by reflection confocal imaging compared with viewing with transmitted brightfield optics. For Type I, prominent staining of cytoplasmic organelles having a distribution consistent with that of mitochondria was noted. For Type III, intense staining at the nuclear periphery was observed. A distinct punctate pattern along the nuclear surface implied a nonuniform distribution of the Type III hexokinase and may represent preferential association with nuclear pore structures. A study of technical factors involved in optimizing the reflection image was conducted. We demonstrate that both the choice of objective and the thickness of the mounting medium are critical to successful imaging, and we describe a simple test for assessing the suitability of objectives in any system.
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PMID:Reflection confocal imaging of type I and type III isozymes of hexokinase in PC12 cells. 751 49

4-Aminodiphenylamine (N-phenyl-1,4-phenylenediamine, CAS 101-54-2) and its water-soluble HCl salt (CAS 2198-59-6) were demonstrated to be efficient mediators for glucose oxidase, lactate oxidase, xanthine oxidase, and lysine oxidase. Using cyclic voltammetry, single oxidative peak potentials were observed for scans ranging from 0 to 0.5 V vs Ag/AgCl. The half-wave potential for both preparations was 0.11 V vs Ag/AgCl at pH 7 and decreased 59 mV per unit pH increase. Peak current data were analyzed to estimate diffusivities of 0.8 x 10(-5) cm2/s for soluble 4-ADPA HCl, and 2.36 x 10(-5) cm2/s for 4-ADPA solubilized in 2.5 mM 2-hydroxypropyl-beta-cyclodextrin. The overall second-order kinetic constants (k) for the reaction of reduced glucose oxidase with oxidized 4-ADPA HCl and 4-ADPA in cyclodextrin were estimated to be 1.8 x 10(5) and 1.7 x 10(-5) M-1 s-1, respectively, using cyclic voltammetry measurements at varied scan rates and enzyme concentrations. Both preparations proved to be suitable electron acceptors for horseradish peroxidase, as indicated by changes in absorbance spectra upon oxidation or reduction. The electrochemical and spectral behavior of the preparations were applied in conjunction with glucose oxidase to devise mediated amperometric and hydrogen peroxide-coupled spectrophotometric assays for glucose. The results of both assays compared favorably with the hexokinase reference method.
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PMID:Dual functionalities of 4-aminodiphenylamine in enzymatic assay and mediated biosensor construction. 859 91

Gliclazide interferes with the glucose determination using the glucose oxidase/peroxidase (EC 1.1.3.4/1.11.1.7) (GOD-PERID) method utilizing 2,2-azino-di-(3-ethyl-benzothiazoline-6-sulphonic acid) (ABTS) as the oxygen acceptor chromogen. There was an essentially linear relationship between the concentrations of gliclazide and decreasing glucose readings. One mu mol/1 of gliclazide in samples leads to an apparent loss of about 2.5 mu mol/l of glucose. However, gliclazide did not interfere with the glucose determination using the hexokinase/glucose-6-phosphate dehydrogenase method. This interference in the GOD-PERID method for glucose assay can occur in the in vitro experimental samples and cause underestimation of the glucose values. It is suggested that careful attention should be paid to the limited applicability of the GOD-PERID method for glucose assay.
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PMID:Interference by gliclazide in the glucose oxidase/peroxidase method for glucose assay. 883 37

The development of immune-mediated diabetes in BB rats may involve a defect of the gastrointestinal tract (GI), as suggested by increased gut permeability. This study aimed at measuring invertase, maltase, lactase, and peroxidase activities in the duodenum of diabetesprone BioBreeding (BBdp) rats and control BioBreeding rats (BBc) given free access to NIH-07 diet up to the time of killing at 60 66 d of age. After washing the entire small intestine, the duodenal mucosa was scraped off in the first 5-cm segment from the pylorus and frozen in distilled water. Invertase, maltase, and lactase activities were measured by monitoring the conversion of [U-(14)C]sucrose, [U-(14)C]maltose, and [D-[1-(14)C]glucose] lactose to radioactive hexoses, which were phosphorylated in the presence of adenosine triphosphatase and yeast hexokinase and then separated from their precursor by ion-exchange chromatography. Peroxidase activity was measured by a spectrophotometric procedure. In the BBdp rats, the activity of invertase, maltase, and lactase averaged, respectively, 70.2 +/- 4.4, 81.2 +/- 4.3, and 75.7 +/- 4.1% (n = 16 and p < 0.001 in all cases) of the control values found in BBc rats of the same sex. Inversely, after exclusion of two female BBc rats with abnormally high plasma D-glucose concentration, the activity of peroxidase in the BBdp rats averaged 157.4 +/- 20.0% (n = 16; p < 0.02) of the mean control value recorded in BBc rats of the same sex (100.0 +/- 9.3%; n = 14). These findings are compatible with the view that a proinflammatory state of the GI associated with compromise function may precede the occurrence of pancreatic insulitis in BBdp rats and, possibly, human subjects with type 1 diabetes.
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PMID:Invertase, maltase, lactase, and peroxidase activities in duodenum of BB rats. 1262 29

Indole-3-acetic acid (IAA) is toxic for human tumor cells and in association with horseradish peroxidase (HRP) can be used as a new prodrug/enzyme combination for targeted cancer therapy. The toxic effect of IAA on neutrophils, macrophages and lymphocytes is associated with cell peroxidase activity, which is high in neutrophils and low in lymphocytes. The effect of IAA on glucose and glutamine metabolism in leukocytes presenting different peroxidase activities: neutrophils, thioglycollate-elicited macrophages and lymphocytes was investigated. A time-course effect (from 6 to 48 h in culture) of IAA on glucose and glutamine metabolism of neutrophils, thioglycollate-elicited macrophages, and lymphocytes was then carried out. Addition of IAA (0.25 mM) did not have a marked effect on glucose utilization and lactate formation by the three cell types but it raised glutamine consumption and glutamate production by neutrophils and macrophages. IAA had no effect on glutamine consumption and glutamate production by lymphocytes. A strong relationship was found between glutamine utilization (0.999) and glutamate production (0.999) and peroxidase activity. IAA did not change the activities of hexokinase, glucose-6-phosphate dehydrogenase, citrate synthase, lactate dehydrogenase, and phosphate-dependent glutaminase of 24 h cultured neutrophils and lymphocytes. The effect of IAA (1 mM) on glucose and glutamine metabolism was also investigated by 1 h incubated leukocytes in PBS. IAA did not affect glucose and glutamine metabolism of lymphocytes but enhanced glucose and glutamine metabolism by 1 h incubated neutrophils and thioglycollate-elicited macrophages. IAA caused a marked increase on oxygen consumption by neutrophils, which was more pronounced in the presence of the glutamine as compared to glucose. The stimulation of oxygen consumption leads to a reduction in NADH/NAD+ ratio that activates the flux of substrates through the Krebs cycle. Since glutamine is mainly metabolized through the left hand side of the Krebs cycle, a reduction in the redox state of the cells may accelerate the flux of substrates through glutaminolysis. The toxic results presented here show that the affect of IAA in association with peroxidase involves activation of glutamine metabolism.
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PMID:Indole-3-acetic acid increases glutamine utilization by high peroxidase activity-presenting leukocytes. 1526 71

Alcoholic extract of the stems of Coscinium fenestratum, a medicinal plant indigenous to India and Sri Lanka used in ayurveda and siddha medicine for treating diabetes, was studied for its carbohydrate metabolism effect and antioxidant status in streptozotocin-nicotinamide induced type 2 diabetic rats. Oral administration of C. fenestratum stem extract in graded doses caused a significant increase in enzymatic antioxidants such as catalase, superoxide dismutase, glutathione synthetase, peroxidase, and glutathione peroxidase and in the nonenzymatic antioxidants ascorbic acid, ceruloplasmin and tocopherol. Effects of alcoholic extract on glycolytic enzymes such as glucose-6-phosphate dehydrogenase, lactate dehydrogenase and hexokinase showed a significant increase in their levels, whereas a significant decrease was observed in the levels of gluconeogenic enzyme, glucose-6-phosphatase and alanine aminotransferase in treated diabetic rats. Serum creatinine and urea levels also declined significantly. This investigation demonstrates significant antidiabetic activity of C. fenestratum.
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PMID:Alcoholic stem extract of Coscinium fenestratum regulates carbohydrate metabolism and improves antioxidant status in streptozotocin-nicotinamide induced diabetic rats. 1613 16

In the growing chloronema cell suspension cultures of the moss Funaria hygrometrica Hedw., activities of several enzymes have been found to be cell-density-dependent. Cyclic nucleotide phosphodiesterase (cNPDE), nitrate reductase (NR), and protein kinase showed highest activity at a low cell density (1 to 2 milligrams per milliliter) while indoleacetic acid (IAA) oxidase and peroxidase were highest at a high cell density (>10 milligrams per milliliter). 3'-Nucleotidase and the glycolytic enzymes (aldolase, hexokinase, phosphofructokinase, phosphoglucoisomerase, pyruvate kinase, and triose phosphate isomerase) showed no significant dependence on the cell density. Alternatively, if the NR and peroxidase activities were determined as a function of time in batch cultures, their levels were maximal 60 to 70 and 320 hours after subculture, respectively, the corresponding cell densities being 1 to 2 and 23 milligrams per milliliter. The relationship between cell density and NR and peroxidase activities is the same, whether these enzymes are measured in batch cultures during a growth cycle or in the cells cultured at different initial inoculum densities for a constant time. Conventionally enzymic changes have been correlated with growth phases; however, it is felt that the pattern of enzymic activities can also be interpreted as cell-density-dependent.In moss protonema, the dependence of cNPDE, IAA oxidase, and peroxidase on cell density may play an important role in modulating the endogenous levels of IAA and cAMP, both of which regulate the differentiation of specific cell types (Johri and Desai 1973 Nature New Biol 245: 223-224; and Handa and Johri 1976 Nature 259: 480-482).
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PMID:Cell-density-dependent Changes in the Metabolism of Chloronema Cell Cultures: I. Relationship between Cell Density and Enzymic Activities. 1666 Sep 5

Mitochondrial hexokinase (mt-HK) and creatine kinase (mt-CK) activities have been recently proposed to reduce the rate of mitochondrial ROS generation through an ADP re-cycling mechanism. Here, we determined the role of mt-HK and mt-CK activities in regulate mitochondrial ROS generation in rat brain, kidney, heart and liver, relating them to the levels of classical antioxidant enzymes. The activities of both kinases were significantly higher in the brain than in other tissues, whereas the activities of catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) were higher in both liver and kidney mitochondria. In contrast, manganese superoxide dismutase (Mn-SOD) activity was not significantly different among these tissues. Activation of mitochondrial kinases by addition of their substrates increased the ADP re-cycling and thus the respiration by enhancing the oxidative phosphorylation. Succinate induced hydrogen peroxide (H(2)O(2)) generation was higher in brain than in kidney and heart mitochondria, and the lowest in liver mitochondria. Mitochondrial membrane potential (DeltaPsi(m)) and H(2)O(2) production, decreased with additions of 2-DOG or Cr to respiring brain and kidney mitochondria but not to liver. The inhibition of H(2)O(2) production by 2-DOG and Cr correspond to almost 100% in rat brain and about 70% in kidney mitochondria. Together our data suggest that mitochondrial kinases activities are potent preventive antioxidant mechanism in mitochondria with low peroxidase activities, complementing the classical antioxidant enzymes against oxidative stress.
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PMID:Reactive oxygen species generation is modulated by mitochondrial kinases: correlation with mitochondrial antioxidant peroxidases in rat tissues. 1863 44

Photodynamic therapy (PDT) is based on the light-induced activation of a photosensitizer generating highly reactive oxygen species that induce tissue destruction in malignant tissues. The present study was carried out to assess the photosensitizing potential of bis(3,5-diiodo-2,4,6-trihydroxyphenyl)squaraine in PDT trials in vivo. Male Swiss albino mice were divided into five groups. Skin tumor was induced using 7,12-dimethylbenz(a)anthracene - DMBA in the animals of Groups II, III, IV and V, while animals of Group I served as the control. At the completion of 20 weeks of induction, the tumor bearing mice from Group III, IV and V were given an intraperitoneal injection with the squaraine dye (12.5mg/kg body weight). After 24h, in the Group IV and V animals, the tumor area was exposed to visible light from a 1000W halogen lamp. The mice from groups I to IV were sacrificed two weeks after the PDT treatment and the marker enzymes (myeloperoxidase [MPO], beta-d-glucuronidase, rhodanese, lactate dehydrogenase [LDH], hexokinase, sialic acid and caspase) were assayed in tumor and normal tissues. Animals from Group V were sacrificed after 90 days of PDT treatment and the above parameters were recorded. Reduction in tumor volume and reversal of biochemical markers to near normal levels were observed in the treatment groups. The study assumes importance as it is the first report on PDT-a novel modality, using a squaraine dye for skin cancer therapy in vivo. The uniqueness of the mode of treatment lies in the selective uptake of squaraine dye by the cancer cells and their selective destruction using PDT without affecting the neighbouring normal cells, which is much advantageous over radiation therapy now frequently used. Also in skin cancer models, the progression/cure can be visualized by the naked eye which is another point of advantage, while seeking new modalities for the treatment of cancer.
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PMID:Bis(3,5-diiodo-2,4,6-trihydroxyphenyl)squaraine: a novel candidate in photodynamic therapy for skin cancer models in vivo. 1865 54

Saraca asoka (Family - Caesalpiniaceae) has been widely used in the Ayurvedic (traditional Indian) system of medicine especially due to its wound healing property. The present study investigated the chemopreventive property of flavonoids from the flowers of Saraca asoka on 7,12 dimethyl benz(a)anthracene (DMBA) induced skin cancer in mice models. A single topical application of DMBA (100 microg/50 microL of acetone) followed after 2 weeks by three times a week treatment with croton oil (1% in acetone), for 20 weeks resulted in tumor induction. The topical application of the flavonoid fraction of S. asoka (FF S. asoka), 30 min prior to the application of croton oil thrice weekly for 20 weeks, caused a significant reduction in the number of tumors per mouse and the percentage of tumor-bearing mice. Also the latency period for the appearance of the first tumor was delayed by S. asoka pretreatment. In the flavonoid fraction (5 mg and 10 mg/kg body weight) treated animals, the levels of biochemical markers - rhodanese, myeloperoxidase, beta-D-glucuronidase, sialic acid, hexokinase and caspase 3 were significantly restored to near normal levels. These findings suggest the chemopreventive activity of flavonoids from S. asoka on two stage skin carcinogenesis. Histological data also support the chemopreventive potential of S. asoka.
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PMID:Chemoprevention of skin cancer by the flavonoid fraction of Saraca asoka. 1961 29


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