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Query: EC:1.2.1.13 (
glyceraldehyde-3-phosphate dehydrogenase
)
6,511
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The
glucose
consumption rate versus ATP content in human red cells (regulatory patterns of glycolysis) and ATP concentration versus
glucose
uptake rate in red cell suspension (regulatory patterns of total ATPases), when the rate of
glucose
uptake is constant and lower than the rate of
glucose
consumption at physiological conditions, were measured at different pH values. The shape of both types of kinetic curves was found to be dependent on the pH of the incubation medium but the same for the red cells taken from different donors. It is supposed that at alkaline pH,
glyceraldehyde-3-phosphate dehydrogenase
and phosphoglycerate kinase reactions become the rate-limiting steps of glycolysis instead of hexokinase and phosphofructokinase under physiological conditions.
...
PMID:[Effect of pH on the regulatory characteristics of energy metabolism in human erythrocytes]. 376 40
Metabolic changes have been investigated during continuous growth of yeast cells inoculated in
glucose
-containing medium until the cells entered the stationary phase in response to
glucose
exhaustion. Well in advance of
glucose
exhaustion, a transition phase was observed, characterized by a decrease in the growth rate and a progressive reduction of protein and RNA accumulation. Two-dimensional gel analysis of the proteins synthesized during this stage showed that the pattern of proteins remained similar to that of log-phase cells. When the cells entered the stationary phase, protein accumulation was 10% of that in log-phase cells, and incorporation of labeled RNA precursor was undetectable. Analysis of protein synthesis gave evidence that the synthesis of 95% of the proteins present in log-phase cells was arrested in stationary-phase cells. Among the 20 proteins whose synthesis continues throughout the stationary phase were identified actin, aldehyde dehydrogenase, enolase, hexokinase,
glyceraldehyde-3-phosphate dehydrogenase
, and five heat shock proteins. In addition, the synthesis of six new proteins was observed. The occurrence of these new proteins in stationary-phase cells is presumed to result from the release of carbon catabolite repression due to
glucose
exhaustion.
...
PMID:Protein synthesis during transition and stationary phases under glucose limitation in Saccharomyces cerevisiae. 388 94
The fasting hypoglycemia (1.78 +/- 0.29 mmol/l) which develops in 48-h-old pigs is partially reversed (3.85 +/- 0.55 mmol/l) after gastric administration of long-chain triglycerides (LCT). The increase in blood
glucose
induced by LCT feeding was not secondary to a decreased
glucose
utilization because
glucose
disappearance rate increased in LCT-fed piglets but resulted from a twofold increase in
glucose
appearance. By using the crossover-plot technique, the stimulation of hepatic gluconeogenesis induced by LCT feeding has been localized at 1) the level of pyruvate carboxylase owing to the twofold increase in hepatic acetyl-CoA concentration and 2) the level of
glyceraldehyde-3-phosphate dehydrogenase
secondary to the increase in reducing equivalents (NADH), which displaces this equilibrium reaction in the direction of gluconeogenesis. As blood lactate, pyruvate, and alanine concentrations increased after LCT feeding, the possible effects of LCT on pyruvate dehydrogenase in peripheral tissues are discussed. These data demonstrate that fatty acids stimulate hepatic gluconeogenesis in 48-h-old fasting piglets and underline the role of fat provision in the regulation of
glucose
homeostasis during the neonatal period in the pig.
...
PMID:Effect of intragastric triglyceride administration on glucose homeostasis in newborn pigs. 389 65
Utilizing yeast strains containing insertion mutations in each of the three
glyceraldehyde-3-phosphate dehydrogenase
structural genes, the level of expression of each gene was determined in logarithmically growing cells. The contribution of the TDH1, TDH2, and TDH3 gene products to the total
glyceraldehyde-3-phosphate dehydrogenase
activity in wild type cells is 10-15, 25-30, and 50-60%, respectively. The relative proportions of expression of each gene is the same in cells grown in the presence of
glucose
or ethanol as carbon source although the total
glyceraldehyde-3-phosphate dehydrogenase
activity in cells grown in the presence of
glucose
is 2-fold higher than in cells grown on ethanol. The polypeptides encoded by each of the structural genes were identified by two-dimensional polyacrylamide gel electrophoresis. The TDH3 structural gene encodes two resolvable forms of
glyceraldehyde-3-phosphate dehydrogenase
which differ by their net charge. The apparent specific activity of
glyceraldehyde-3-phosphate dehydrogenase
encoded by the TDH3 structural gene is severalfold lower than the enzymes encoded by TDH1 or TDH2. The polypeptides encoded by the TDH2 or TDH3 structural genes form catalytically active homotetramers. The apparent Vmax for the homotetramer encoded by TDH3 is 2-3-fold lower than the homotetramer encoded by TDH2. Evidence is presented that isozymes of
glyceraldehyde-3-phosphate dehydrogenase
exist in yeast cells, however, the number of different isozymes formed was not established. These data confirm that the three yeast
glyceraldehyde-3-phosphate dehydrogenase
genes encode catalytically active enzyme and that the genes are expressed at different levels during logarithmic cell growth.
...
PMID:Differential expression of the three yeast glyceraldehyde-3-phosphate dehydrogenase genes. 390 88
An aryl azide derivative of glucosamine, N-(4-iodoazidosalicyl)-2-amido-2-deoxy-D-glucopyranose (GlcNAs), was synthesized as a potential photoaffinity label for the facilitative
hexose
carrier. The derivative inhibited
hexose
uptake into intact human erythrocytes half-maximally at 3.5 mM and was itself slowly transported into cells. However, photolysis of iodinated GlcNAs with leaky erythrocyte ghosts produced appreciable labeling on gel electrophoresis only of Band 6, which is
glyceraldehyde-3-phosphate dehydrogenase
. Band 6 photolabeling in leaky ghosts by GlcNAs was: saturable, due mostly to the aryl azide moiety, inhibited by agents with known affinity for the enzyme including sulfhydryl reagents and the enzyme substrate glyceraldehyde-3-phosphate, and not inhibited by the free-radical scavenger p-aminobenzoic acid. Moreover, GlcNAs also inhibited erythrocyte
glyceraldehyde-3-phosphate dehydrogenase
activity in a dose-dependent fashion in the dark and more potently following irradiation. In resealed ghosts, Band 6 labeling was decreased by D-glucose, reflecting inhibition of carrier-mediated uptake of the agent. GlcNAs appears to be a specific photoaffinity label for erythrocyte
glyceraldehyde-3-phosphate dehydrogenase
, and therefore potentially useful for studies of enzyme activity, compartmentation, or membrane association.
...
PMID:Photoaffinity labeling of glyceraldehyde-3-phosphate dehydrogenase by an aryl azide derivative of glucosamine in human erythrocytes. 394 33
By using very low concentrations of cells to minimize alterations in substrate concentrations, we demonstrated that the lactate/pyruvate ratio of the incubation medium, which determines the cytosolic NADH/NAD+ ratio, affects gluconeogenic flux in suspensions of isolated hepatocytes from fasted rats. At a fixed extracellular pyruvate concentration of 1 mM and with the lactate/pyruvate ratio varied from 0.6 to 10 and to 50,
glucose
production rates increased from 2.5 to 5.5 and then decreased to 1.8 nmol/mg of cell protein/min. This finding paralleled the observation of Sugano et al. (Sugano, T., Shiota, M., Tanaka, T., Miyamae, Y., Shimada, M., and Oshino, N. (1980) J. Biochem. (Tokyo) 87, 153-166) who noted a similar biphasic response in the perfused liver system when lactate was held constant and pyruvate varied. The biphasic relationship can be explained by the influence of the NADH/NAD+ ratio on the near-equilibrium reactions catalyzed by
glyceraldehyde-3-phosphate dehydrogenase
and malate dehydrogenase in the hepatocyte cytosol. By shifting the equilibrium of the
glyceraldehyde-3-phosphate dehydrogenase
reaction, a rise in the NADH/NAD+ ratio decreases the concentration of 3-phosphoglycerate which, because of the linkage of 3-phosphoglycerate to phosphoenolpyruvate through two near-equilibrium reactions, reduces the concentration of phosphoenolpyruvate and therefore causes a decline in flux through pyruvate kinase. This decrease in pyruvate kinase flux results in an enhanced gluconeogenic flux. At higher NADH/NAD+ ratios, however, the oxalacetate concentration drops to such an extent that the consequent decreased flux through phosphoenolpyruvate carboxykinase exceeds the decline in flux through pyruvate kinase, producing a decrease in gluconeogenic flux. The lactate/pyruvate ratio was found to influence the actions of three hormones thought to stimulate gluconeogenesis by different mechanisms. Except for an inhibition by glucagon seen at the lowest lactate/pyruvate ratio tested, the stimulations by this hormone were relatively insensitive to lactate/pyruvate ratios, while angiotensin II produced greater stimulations of gluconeogenesis as the lactate/pyruvate ratio was increased. Dexamethasone, added in vitro, stimulated gluconeogenesis significantly only at very low and very high lactate/pyruvate ratios.
...
PMID:The interaction between the cytosolic pyridine nucleotide redox potential and gluconeogenesis from lactate/pyruvate in isolated rat hepatocytes. Implications for investigations of hormone action. 404 7
The biochemical mechanisms of the acidogenic potential of Streptococcus sanguis ATCC 10556 grown in
glucose
-excess and
glucose
-limited continuous culture were studied. The rate of acid production during the
glucose
metabolism by the cells grown under
glucose
limitation (
glucose
-limited cells) was 2.1 to 2.6 times that by the cells grown in an excess of
glucose
(
glucose
-excess cells). When the
glucose
-limited cells were metabolizing
glucose
, intracellular concentrations of
glucose
6-phosphate, fructose 6-phosphate, 3-phosphoglycerate, and pyruvate were higher, and that of glyceraldehyde 3-phosphate was lower, than those when the
glucose
-excess cells were metabolizing
glucose
. The levels of fructose 1,6-bisphosphate and dihydroxyacetone phosphate were not significantly different between these cells. The activities of
glucose
-phosphoenolpyruvate phosphotransferase system in decriptified cells and
glyceraldehyde-3-phosphate dehydrogenase
in cell-free extracts of the
glucose
-limited cells were higher than those in the
glucose
-excess cells. The activities of glucokinase, phosphoglycerate kinase, and pyruvate kinase in cell-free extracts of these cells were not different significantly. We conclude that the high glycolytic activity of the
glucose
-limited cells results from the increase in the synthesis of
glucose
-phosphoenolpyruvate phosphotransferase and
glyceraldehyde-3-phosphate dehydrogenase
.
...
PMID:Regulation of glycolytic rate in Streptococcus sanguis grown under glucose-limited and glucose-excess conditions in a chemostat. 405 23
Crude extracts of both vegetative cells and glycerol-induced microcysts of Myxococcus xanthus contained the following enzyme activities: phosphofructokinase, phosphoglucoisomerase, fructose-1,6-diphosphatase, fructosediphosphate aldolase,
glyceraldehyde-3-phosphate dehydrogenase
, phosphopyruvate carboxylase, citrate synthase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase, and uridine diphosphate
glucose
pyrophosphorylase. With the exception of isocitrate dehydrogenase, which was present at a fivefold higher concentration in microcysts, all activities in extracts from both types of cells were essentially equal. Hexokinase and pyruvate kinase could not be detected in extracts from either type of cell. Microcysts metabolized acetate at a lower rate than did vegetative cells. Most of this decrease was reflected in a substantial decrease in ability of microcysts to oxidize acetate to CO(2). In addition, microcysts and vegetative cells showed a different distribution of (14)C-label from incorporated acetate.
...
PMID:Comparative intermediary metabolism of vegetative cells and microcysts of Myxococcus xanthus. 430 96
Purified preparations of Coxiella burnetii were examined for enzymes of the glycolytic pathway.
Glucose
-phosphate isomerase, fructose-1,6-diphosphatase, aldolase,
glyceraldehyde-3-phosphate dehydrogenase
, and pyruvate kinase were shown to be present in C. burnetii extracts. Heat-killed C. burnetii purified with normal yolk sacs demonstrated no activity after disruption. Aldolase was shown to be of the class II type by complete inhibition of activity in the presence of 8 x 10(-3)m ethylenediaminetetraacetic acid. The host enzyme activity (normal and infected yolk sacs) was not affected by the same treatment. When cellulose acetate electrophoresis was performed on the extracts, aldolase from both normal and infected yolk sacs exhibited five isozyme bands, whereas aldolase from the C. burnetii extract appeared as a single band.
...
PMID:Biochemistry of Coxiella burnetii: Embden-Meyerhof pathway. 432 56
The inability of Micrococcus sodonensis to grow on
glucose
as the sole source of carbon and energy was investigated. Estimation of pathways of
glucose
catabolism indicated that both the glycolytic and
hexose
monophosphate pathways are present in this organism. Comparative studies with Escherichia coli demonstrated that key enzymes for
glucose
catabolism were present in M. sodonensis in quantities equivalent to those of E. coli. The glucose-6-phosphate and 6-phosphogluconate dehydrogenases of M. sodonensis were nicotinamide adenine dinucleotide phosphate (NADP) specific, and
glyceraldehyde-3-phosphate dehydrogenase
was nicotinamide adenine dinucleotide specific. Transhydrogenase and reduced NADP oxidase were absent. Growth of the organism in the presence of
glucose
did not result in a repressed ability to oxidize tricarboxylic acid cycle intermediates, but these cells did have a decreased capacity for
glucose
degradation. The addition of substrates rich in growth-promoting substances, e.g., yeast extract, did not provide requisite nutrients for growth on
glucose
. Studies with (32)P suggest that M. sodonensis is incapable of synthesizing energy-rich phosphate compounds during the catabolism of
glucose
.
...
PMID:Glucose catabolism in Micrococcus sodonensis. 438 30
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