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

---

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

In order to test the possible involvement of surface proteins on some metabolical aspects of chick glial cell differentiation in culture, perturbations were induced on the glial cell surface membrane by limited trypsinization before seeding. The developmental changes of enzymes involved in the energy metabolism of the cell: malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), hexokinase (HK), lactate dehydrogenase (LDH), enolase as well as glutamine synthetase (GS) were determined in trypsin treated cells and controls. The total protein and DNA content per dish was higher in treated cells than in controls, however the protein ratio towards DNA remained unchanged. The levels of GS, GDH, LDH, and enolase activities were significantly enhanced after trypsin treatment of the cells compared to controls. The enhanced value of total LDH activity is essentially the result of the increase of M subunit containing isoenzymes. Considering that a higher level of GS activity characterizes some maturation of the glial cells (as observed during the maturation of the chick brain) it is apparent that modifications of cell surface located factors, by trypsin treatment, induce differentiation phenomena at the functional state of the glial cells in culture. This may indicate that interactions located at the cell surface are involved in the modulation of key enzymes of the energy metabolism pathway.
...
PMID:Trypsinization of chick glial cells before seeding: effects on energy metabolism enzymes and glutamine synthetase. 614 Jun 46

Red cell enzymes, 2,3-diphosphoglycerate (2,3-DPG) and adenosine triphosphate (ATP), were evaluated in a 23-mo-old boy with juvenile chronic myelocytic leukemia (JCML) at the onset of his illness and 6 mo later during the accelerated phase. The activities of the age-dependent red cell enzymes, hexokinase, aldolase, pyruvate kinase, and glucose-6-phosphate dehydrogenase, were elevated, as were the concentrations of red cell 2,3-DPG and ATP, consistent with a young red cell population metabolizing at an increased glycolytic rate. The activities of the non-age-dependent enzymes, glyceraldehyde-3-phosphate dehydrogenase (G3PD), phosphoglycerate kinase, and enolase, were also increased to levels similar to or greater than those observed in term infants. As the illness progressed, the activity of red cell G3PD increased further, and phosphoglucose isomerase activity increased markedly. These results are consistent with the prior suggestion that JCML represents a reversion to "fetal" erythropoiesis.
...
PMID:Fetal erythropoiesis in juvenile chronic myelocytic leukemia. 622 20

Phosphoglycerate kinase deficiency is a rate, X-linked disorder associated with a severe haemolytic anaemia. In general the deficiency has been demonstrated only in erythrocytes and leucocytes. However, in a subject with this condition, the activity of phosphoglycerate kinase in lymphocytes and platelets was also shown to be less than 5% of the normal value. Following the death of this subject in 1979, the deficiency was also found to occur in tissue samples of brain, skeletal muscle, liver and cardiac muscle, obtained at the autopsy. Values for phosphoglycerate kinase were of the order of 0.5-5% of normal controls. Other glycolytic enzymes which were tested were hexokinase, pyruvate kinase, enolase and 2-phosphoglyceromutase. In general, values for these enzymes were either normal or slightly raised.
...
PMID:Tissue levels of glycolytic enzymes in phosphoglycerate kinase deficiency. 625 1

In order to evaluate properly red cell metabolic data obtained in newborns with congenital hemolytic disorders, the unique metabolic characteristics and normal developmental changes that occur prenatally and postnatally are presented. The age-dependent red cell glycolytic enzymes (hexokinase, aldolase, pyruvate kinase) and glucose-6-phosphate dehydrogenase and most glycolytic intermediates are elevated at birth and at 11 to 12 months of age, consistent with the presence of a young red cell population the entire first year of life. However, certain red cell enzymes are elevated out of proportion to the age of the red cell population [phosphoglucose isomerase. glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase (PGK), and enolase (ENO)] whereas others are decreased [phosphofructokinase (PFK), glutathione peroxidase, carbonic anhydrase, and others]. These metabolic characteristics are felt to be unique and representative of "fetal erythropoiesis." Activities of PGK and ENO decrease the PFK increases toward normal adult values beginning at eight to nine weeks of age. The concentration of glucose-6-phosphate steadily increases after birth and peaks at three to four weeks of age, at a time when PFK activity remains relatively unchanged, suggesting a relative block in glycolysis at the PFK step secondary to an enzyme with both decreased activity and altered kinetic properties (a "fetal" isozyme). Thus, evaluation of red cell enzyme and glycolytic intermediate data obtained in the first year of life should be related to the knowledge that a young red cell population is present and the characteristic unique metabolic red cell alterations described in cord blood persist beyond the immediate neonatal period.
...
PMID:Red cell enzymopathies in the newborn. I. Evaluation of red cell metabolism. 628 May 78

A marked reduction of granulocyte chemotactic function accompanies the storage of granulocyte concentrates. Since chemotaxis is energy dependent, we studied energy metabolism in stored neutrophils. We and others have reported that stored neutrophils have a defect in their energy metabolism. We found that defective adenosine triphosphate maintenance in stored neutrophils was occult in resting cells, but was unmasked by an energy-intensive stimulus, phagocytosis. In studies reported here, we sought to determine if defective adenosine triphosphate maintenance during granulocyte storage was related to altered glycolytic enzyme activity. We studied the activity of glycolytic enzymes in fresh and stored, resting and stimulated (opsonized zymosan) neutrophils. The following enzyme activities showed no major changes during storage, in resting or stimulated neutrophils: hexokinase, phosphofructokinase, aldolase, glucose phosphate isomerase, triose phosphate isomerase, glyceraldehyde phosphate dehydrogenase, phosphoglycerate kinase, phosphoglyceromutase, enolase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, glutathione reductase, and glutathione peroxidase. In contrast, pyruvate kinase activity consistently increased during storage. In 6 units, pyruvate kinase activity increased by 75 percent after 24 hours of storage at room temperature and by 198 percent after 48 hours. The storage-associated increase in pyruvate kinase activity was not inhibited by cycloheximide. Stimulation of neutrophils by phagocytosis of opsonized zymosan also produced striking increases in the pyruvate kinase activity of both fresh and stored cells. Additional studies indicated that the increases in pyruvate kinase activity observed during storage and after phagocytosis were associated with an increase in the availability of pyruvate kinase activity in the supernatant fraction of neutrophil sonicates. Total pyruvate kinase activity in sonicates of neutrophils was unchanged by storage or particle ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Glycolytic enzymes of stored granulocytes. 632 24

The activities of red cell enzymes enolase (ENO), phosphoglycerate kinase (PGK), phosphofructokinase (PFK), glucose-6-phosphate dehydrogenase (G-6-PD), hexokinase (HK), aldolase (ALD), and pyruvate kinase (PK) were followed sequentially in term infants from birth to one year of age. At birth, red cell PGK and ENO activities were disproportionately elevated when compared to both red cells with a similar mean cell age and those with a younger mean cell age; red cell PFK was significantly decreased. There was a progressive full in PGK and ENO activities and rise in PFK levels toward normal values in the first year of life. The most significant changes in PGK, ENO, and PFK appeared to begin at 8 to 9 wk of age. ENO and PFK activities stabilized at approximately 5 to 6 months of age at values compatible with mean cell age; mean PGK levels remained mildly elevated at 11 to 12 months. The age-dependent enzymes G-6-PD, PK, ALD, and HK were all elevated in term newborns. G-6-PD and ALD progressively decreased in activity during the first year of life. PK and HK decreased in activity until 8 to 9 wk when there was a secondary rise in mean activity. Mean red cell G-6-PD, PK, ALD, and HK levels remained mildly to moderately elevated at 11 to 12 months of life, suggesting the persistence of a relatively young red cell population throughout the first year of life.
...
PMID:Red cell metabolic alterations in postnatal life in term infants: glycolytic enzymes and glucose-6-phosphate dehydrogenase. 645 61

Late committed progenitor cells of erythropoiesis, CFU-E (colony-forming unit--erythroid), were isolated from mouse spleens to near homogeneity by a three-step enrichment procedure. The procedure included a four-day pretreatment of bled mice with the antibiotic thiamphenicol, a recovery period of 3 1/2 days, followed by centrifugal elutriation and Percoll density gradient centrifugation of the spleen cells. This practically pure CFU-E population was used to study some aspects of erythroid differentiation in vitro. Colony growth, as well as morphology and glycolytic enzyme activities of cells isolated at selected times of the 48-hour culture period, were determined. Marked declining activities of several enzymes, including hexokinase, phosphofructokinase, aldolase, enolase, pyruvate kinase, and glucose-6-phosphate dehydrogenase, were observed during in vitro differentiation. The activity of diphosphoglycerate mutase was almost absent in the CFU-E, but progressively increased during differentiation. The isozyme distribution of aldolase and enolase did not change during CFU-E in vitro differentiation into the reticulocyte. Hexokinase (HK) in the CFU-E contained mainly a double-banded type I isozyme, in addition to a minor amount of HK II. During differentiation, a shift was noticed within the double-banded HK I region, whereas HK ii disappeared after one cell division. Pyruvate kinase in the CFU-E was characterized by the presence of both the K-type and the L-type isozyme and hybrids of these isozyme types. During in vitro differentiation, the production of the K-type isozyme rapidly stops in favor of the L type.
...
PMID:Changes in activities and isozyme patterns of glycolytic enzymes during erythroid differentiation in vitro. 646 70

1. Activities of 20 red cell enzymes were compared in 8 normal female Ovis Aries, in a serially bled ewe followed by 243 days, and in young and old red cell populations separated by density gradient centrifugation. 2. These comparisons indicate that the erythrocyte enzymes which show significant changes with cell age are glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokinase, phosphoglucose isomerase, lactate dehydrogenase, glutathione reductase, enolase and phosphoglycerate kinase. 3. The usefulness of these data in interpretation of enzyme activities from fetal Ovis Aries is discussed.
...
PMID:Erythrocyte enzymes in Ovis aries. Effect of cell age. 706 Mar 50

Developmental changes in lactate dehydrogenase (LDH), enolase, hexokinase (HK), malate dehydrogenase (MDH), and glutamate dehydrogenase (GDH) activities were measured in cultures of pure neurons and glial cells prepared from brains of chick embryos (8 day-old for neurons, 14 day-old for glial cells) as a function of cellular development with time in culture. The modifications observed in culture were compared to those measured in brain extracts during the development of the nervous tissue in the chick embryo and during the post-hatching period. A significant increase of MDH, GDH, LDH, and enolase activities are observed in neurons between 3 and 6 days of culture, whereas simultaneously a decrease of HK values occurs. In the embryonic brain between 11 and 14 days of incubation, which would correspond for the neuronal cultures to day 3 through 6, modifications of MDH, GDH, HK, and enolase levels are similar to those observed in neurons in culture. Only the increase of LDH activity is less pronounced in vivo than in cultivated cells. The evolution of the tested enzymatic activities in the brain of the chick during the period between 7 days before and 10 days after hatching is quite similar to that observed in cultivated glial cells (prepared from 14 day-old embryos) between 6 and 18 days of culture. All tested activities increased in comparable proportions. The modifications of the enzymatic profile indicate that some maturation phenomena affecting energy metabolism of neuronal and glial elements in culture, are quite similar to those occuring in the total nervous tissue. A relationship between the development of the energy metabolism of the brain and differentiation processes affecting neuroblasts and the glial-forming cells is discussed.
...
PMID:Modifications in energy metabolism during the development of chick glial cells and neurons in culture. 707 May 78

Red cell glycolytic intermediates and enzymes in term infants in the first year of life were correlated with the fetal hemoglobin concentration (%F), intra- and extracellular venous pH, plasma inorganic phosphorus (Pi) and pyruvate kinase (PK) activity. Changes in the non-age-dependent enzymes phosphoglycerate kinase, enolase, and phosphofructokinase correlated most significantly with the postnatal decline in %F (P less than 0.001), not the age of the red cell population, as reflected in PK activity. The age-dependent enzymes, hexokinase and glucose-6-phosphate dehydrogenase, however, correlated well with PK activity (P less than 0.001). The concentration of glucose-6-phosphate did not correlate significantly with the postnatal decline in %F (P greater than 0.05) or PK (P greater than 0.10), but correalted significantly with the plasma Pi concentration (P less than 0.001). "Total triose phosphate" and 2,3-diphosphoglycerate did not correlate with Pi. It appears from these studies that an extracellular factor, Pi alters the pattern of glycolytic intermediates in term infants and that the postnatal changes in phosphoglycerate kinase, enolase, and phosphofructokinase are unique to the "fetal" red cell and reflect passage from fetal to "adult" erythropoiesis.
...
PMID:Red cell metabolic alterations in postnatal life in term infants: possible control mechanisms. 725 39


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

---