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)

In non-nervous tissues, glucocorticoids (GCs) counteract the effects of insulin and stimulate gluconeogenesis. The present study was designed to investigate whether or not adrenalectomy (ADX) and glucocorticoid substitution influence the pathway of both glucose and glycogen metabolism in cerebral parietotemporal cortex and hippocampus, and if so how. The activities of respective key enzymes, such as hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), glucose-6-phosphatase (G6Pase) and phosphorylase a (PLa), and the concentrations of the intermediates, such as glucose (Glu), glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), fructose-1,6-bisphosphate (F16PP), pyruvate (Pyr), lactate (Lac), glycogen (Glyc) and glucose-1-phosphate (G1P), were measured in the brains of 1-year-old male Wistar rats under controlled conditions 3 days after ADX or sham operation and in a pilot study after ADX and substitution with corticosterone (CST) suspended in sesame oil or after ADX and subcutaneous administration of the vehicle only. An increase in both glycolytic flux and glycogen breakdown and a decrease in gluconeogenesis in cerebral cortex but not in hippocampus were observed after ADX. After substitution with CST in adrenalectomized rats the effect of ADX on enzyme activities was reversed: significant differences from adrenalectomized rats that received vehicle only was shown for PK and G6Pase activities in both areas of the rat brain investigated.
 ...
PMID:Effect of adrenalectomy and corticosterone substitution on glucose and glycogen metabolism in rat brain. 902 80

The Embden-Meyerhof (EM) or Entner-Doudoroff (ED) pathways of sugar degradation were analyzed in representative species of the hyperthermophilic archaeal genera Thermococcus, Desulfurococcus, Thermoproteus, and Sulfolobus, and in the hyperthermophilic (eu)bacterial genus Thermotoga. The analyses included (1) determination of 13C-labeling patterns by 1H- and 13C-NMR spectroscopy of fermentation products derived from pyruvate after fermentation of specifically 13C-labeled glucose by cell suspensions, (2) identification of intermediates of sugar degradation after conversion of 14C-labeled glucose by cell extracts, and (3) measurements of enzyme activities in cell extracts. Thermococcus celer and Thermococcus litoralis fermented 13C-glucose to acetate and alanine via a modified EM pathway (100%). This modification involves ADP-dependent hexokinase, 6-phosphofructokinase, and glyceraldehyde-3-phosphate:ferredoxin oxidoreductase (GAP:FdOR). Desulfurococcus amylolyticus fermented 13C-glucose to acetate via a modified EM pathway in which GAP:FdOR replaces GAP-DH/phosphoglycerate kinase. Thermoproteus tenax fermented 13C-glucose to low amounts of acetate and alanine via simultaneous operation of the EM pathway (85%) and the ED pathway (15%). Aerobic Sulfolobus acidocaldarius fermented 13C-labeled glucose to low amounts of acetate and alanine exclusively via the ED pathway. The anaerobic (eu)bacterium Thermotoga maritima fermented 13C-glucose to acetate and lactate via the EM pathway (85%) and the ED pathway (15%). Cell extracts contained glucose-6-phosphate dehydrogenase and 2-keto-3-deoxy-6-phosphogluconate aldolase, key enzymes of the conventional phosphorylated ED pathway, and, as reported previously, all enzymes of the conventional EM pathway. In conclusion, glucose was degraded by hyperthermophilic archaea to pyruvate either via modified EM pathways with different types of hexose kinases and GAP-oxidizing enzymes, by the nonphosphorylated ED pathway, or by a combination of both pathways. In contrast, glucose catabolism in the hyperthermophilic (eu)bacterium Thermotoga involves the conventional forms of the EM and ED pathways. The data are in accordance with various previous reports.
 ...
PMID:Comparative analysis of Embden-Meyerhof and Entner-Doudoroff glycolytic pathways in hyperthermophilic archaea and the bacterium Thermotoga. 907 22

The hyperthermophilic, sulfate-reducing archaeon Archaeoglobus fulgidus strain 7324, rather than the type strain VC16, was found to grow on starch and sulfate as energy and carbon source. Fermentation products and enzyme activities were determined in starch-grown cells and compared to those of cells grown on lactate and sulfate. During exponential growth on starch, 1 mol of glucose-equivalent was incompletely oxidized with sulfate to approximately 2 mol acetate, 2 mol CO2 and 1 mol H2S. Starch-grown cells did not contain measurable amounts of the deazaflavin factor F420 (<0.03 nmol/mg protein) and thus did not show the F420-specific green-blue fluorescence. In contrast, lactate (1 mol) was completely oxidized with sulfate to 3 mol CO2 by strain 7324, and lactate-grown cells contained high amounts of F420 (0.6 nmol/mg protein). In extracts of starch-grown cells, the following enzymes of a modified Embden-Meyerhof pathway were detected: ADP-dependent hexokinase (ADP-HK), phosphoglucose isomerase, ADP-dependent 6-phosphofructokinase (ADP-PFK), fructose-1,6-phosphate aldolase, glyceraldehyde-3-phosphate:ferredoxin oxidoreductase (GAP:FdOR), phosphoglycerate mutase, enolase, and pyruvate kinase (PK). Specific activities of ADP-HK, ADP-PFK, GAP:FdOR, and PK were significantly higher in starch-grown cells than in lactate-grown cells, indicating induction of these enzymes during starch catabolism. Pyruvate conversion to acetate involved pyruvate:ferredoxin oxidoreductase and ADP-forming acetyl-CoA synthetase. The findings indicate that the archaeal sulfate reducer A. fulgidus strain 7324 converts starch to acetate via a modified Embden-Meyerhof pathway and acetyl-CoA synthetase (ADP-forming). This is the first report of growth of a sulfate reducer on starch, i.e. on a polymeric sugar.
 ...
PMID:Sugar utilization in the hyperthermophilic, sulfate-reducing archaeon Archaeoglobus fulgidus strain 7324: starch degradation to acetate and CO2 via a modified Embden-Meyerhof pathway and acetyl-CoA synthetase (ADP-forming). 1170 74