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:1.2.1.13 (glyceraldehyde-3-phosphate dehydrogenase)
6,511 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Incubation of HeLa cells with [32P]orthophosphate results in more rapid labeling of the gamma-phosphorus of ATP than of the intracellular pool of orthophosphate. The specific radioactivity of ATP equals that of extracellular orthophosphate after 2 h of incubation. A similar pattern of labeling is seen with human erythrocytes when incubated at physiological concentrations of orthophosphate (2 mM) and pH 7.4-7.8. At lower pH, 6.8-7.2, the rate of orthophosphate uptake increases and exceeds the rate of labeling of ATP. These data are explained by the existence of a primary system for ATP uptake which involves the mediation of membrane-bound glyceraldehyde-3-phosphate dehydrogenase. Phosphate first enters the cell as 1,3-diphosphoglyceric acid, is then transferred to ATP, and then enters the intracellular orthophosphate pool. At lower pH monovalent orthophosphate also enters the erythrocyte by a process not involving glyceraldehyde-3-phosphate dehydrogenase.
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PMID:Mode of orthophosphate uptake and ATP labeling by mammalian cells. 0 42

Chloroplast NADP-linked glyceraldehyde-3-phosphate dehydrogenase was resolved into three forms that differed in molecular weight: (a) larger than or equal to 1.5 million; (b) 600,000; and (c) less than or equal to 100,000. After preincubation with an effector (ATP, NADPH, or Pi) the activity of forms a and c was unaffected, whereas the activity of b, the regulatory form, was increased 10-fold. Activation was accompanied by the exposure of previously hidden sulfhydryl groups. The rate of activation was slower than the rate of catalysis and resulted in a lag phase during the measurement of activity when the enzyme was preincubated in the absence of an effector. The addition of one of several compounds as a second effector (at a concentration which itself was nonactivating) in the presence of a first effector enhanced activation by lowering the concentration of the first effector required for half-maximal activation (Pi constant/ATP or NADPH varied; ATP or NADPH constant/Pi varied). Other combinations of effectors caused little change in activity (ATP constant/NADPH varied; NADPH constant/ATP varied). Glyceraldehyde 3-phosphate added as a second effector induced contrasting changes: an increase in the ATP-mediated activation and a decrease in the NADPH-mediated activation. The results are consistent with the view that the products of the photochemical reactions of chloroplasts, ATP, and NADPH, in conjunction with other metabolites, regulate the activity of glyceraldehyde-3-phosphate dehydrogenase in the photosynthetic assimilation of CO2.
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PMID:Studies on the regulation of chloroplast NADP-linked glyceraldehyde-3-phosphate dehydrogenase. 1 Feb 97

Effects of glucose concentration and anoxia upon the metabolite concentrations and rates of glycolysis and respiration have been investigated in the perfused liver of the fetal guinea pig. In most cases the metabolite concentrations in the perfused liver were similar to those observed in vivo. Between 50 days and term there was a fall in the respiratory rate and in the concentration of ATP and fructose 1,6-diphosphate and an increase in the concentration of glutamate, glycogen and glucose. Reducing the medium glucose concentration from 10 mM to 1 mM or 0.1 mM depressed lactate production and the concentration of most of the phosphorylated intermediates (except 6-phosphogluconate) in the liver of the 50-day fetus. This indicates a fall in glycolytic rate which is not in accord with the known kinetic properties of hexokinase in the fetal liver. Anoxia increased lactate production by, and the concentrations of, the hexose phosphates ADP and AMP in the 50-day to term fetal liver, while the concentration of ribulose 5-phosphate, ATP and some triose phosphates fell. These results are consistent with an activation of glycolysis, particularly at phosphofructokinase and of a reduction in pentose phosphate pathway activity, particularly at 6-phosphogluconate dehydrogenase. The calculated cytosolic NAD+/NADH ratio for the perfused liver was similar to that measured in vivo and evidence is presented to suggest that the dihydroxyacetone phosphate/glycerol 3-phosphate ratio gives a better indication of cytosolic redox than the lactate/pyruvate ratio. The present observations indicate that phosphofructokinase hexokinase and possibly pyruvate kinase control the glycolytic rate and that glyceraldehyde-3-phosphate dehydrogenase is at equilibrium in the perfused liver of the fetal guinea pig.
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PMID:Some effects of glucose concentration and anoxia on glycolysis and metabolite concentrations in the perfused liver of fetal guinea pig. 2 74

Anoxia has been compared with ischaemia. The abrupt restoration of either oxygen of flow may accelerate cardiac damage. Anoxic stimulation of glycolysis (Pasteur effect) is inhibited during ischaemia by lactate and proton accumulation at the levels of phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. Anaerobic glycolysis provides lactate and ATP; breakdown of the latter provides protons. During partial respiration thought to occur in partial ischaemia, continued production of CO2 is a factor contributing to intracellular acidosis; mitochondrial ATP when formed by continued respiration also yields protons when ultimately broken down. The endoproducts of aerobic glycolysis (pyruvate and NADH) are transported into the mitochondria by the malate-aspartate cycle and by pyruvate dehydrogenase activity. Adenine nucleotide transferase activity normally transfers the mitochondrially-made ATP to the cytoplasm, but acyl CoA accumulates in ischaemia (or during perfusions with high circulating free fatty acids) to inhibit the transferase. The mitochondrial creatine kinase is thought to transform ATP transported outwards into creatine phosphate which can permeate the outer mitochondrial membrane. Further compartmentation of ATP may be by other creatine kinase isoenzymes or in relation to the cell membrane. The glycogenolytic-sarcoplasmic reticulum complex links a glycogen pool to the sarcoplasmic reticulum. Cyclic AMP may regulate admission of calcium to the cell during the plateau of the action potential and promote calcium uptake by the sarcoplasmic reticulum by phosphorylation of phospholamban. The latter promotes the activity of the calcium-transport ATPase. Calcium and cyclic AMP may also interact at the level of the contractile proteins where cyclic AMP phosphrylates troponin. Cyclic GMP generally has opposite effects to cyclic AMP and undergoes opposite changes in the frog cardiac cycle to those of cyclic AMP. A present it is reasonable to suppose that physiological effects of adrenaline or of cholinergic agents on the myocardium are mediated by cyclic AMP or cyclic GMP, respectively, but this hypothesis still lacks firm support. There is an association between tissue cyclic AMP and ventricular fibrillation after coronary ligation, and direct evidence for a role of cyclic AMP in promoting arrhythmias has been obtained by studies on the ventricular fibrillation threshold in the rat heart. However, there are other mechanisms, involving first the effects of substrates on the action potential duration, and secondly, the fast channel, which can also give rise to the development of malignant arrhythmias.
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PMID:Myocardial metabolism and heart disease. 3 41

ATP and quinaldate, two inhibitors of D-glyceraldehyde-3-phosphate dehydrogenase, act antagonistically if [Pi] greater than 1 mM, at pH 7.5 and 25 degrees C. However, the type of interaction of the two inhibitors changes with pH and temperature. Antagonism is strongest at pH values near neutrality and decreases at higher pH. Above pH 9.5 the two inhibitors act nearly additively. At pH 8.5 and [Pi] = 5 mM there is antagonism above 20 degrees C between the two inhibitors whereas there is synergy below 20 degrees C. A lag period in the time course of the enzyme reaction was detected when both inhibitors were present. The lag period is a function of pH. Below pH 8.5 the pH-dependence of the lag period resembles a titration curve with a pKapp greater than 8.
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PMID:pH and temperature dependence of the double inhibition of D-glyceraldehyde-3-phosphate dehydrogenase by ATP and quinaldate. 4 70

Flounder muscle (Pseudopleuronectes americanus) glyceraldehyde-3-phosphate dehydrogenase was characterized as to its stability towards various inactivating treatments in the presence and absence of the enzyme cofactor, NAD. Incubation of a partially purified enzyme preparation at urea concentrations greater than 2 M produced a very rapid inactivation. NAD greatly reduced the rate of inactivation at all the urea concentrations tested. Incubation of each of the three major muscle enzyme forms in 0.1 percent trypsin or chymotrypsin for forty-five minutes decreased the activity of each form by 65 percent and 55 percent, respectively. NAD (5mM) afforded complete protection to each enzyme form from proteolytic digestion by these two enzymes. Exposure of each form to 50 degrees or 20 mM ATP also led to gross inactivation which could be greatly reduced if the respective incubations were performed in the presence of 5mM NAD. NAD was also found to be required for the renaturation of the unfolded urea-denatured subunits to form the active tetramer.
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PMID:Effect of NAD on flounder muscle glyceraldehyde 3-phosphate dehydrogenase. 17 55

Biopsies from vastus lateralis muscle of male patients suffering from chronic ethanol abuse were studied with regard to histochemical reactions of ATPase and NADH-diaphorase; enzymatic activities of triosephosphate dehydrogenase (TPD), lactate dehydrogenase (LD), and cytochrome c oxidase (cytox); content of ATP, creatine phosphate, and glycogen; and volume fractions of fat, mitochondria, and fibrillar and extrafibrillar space. The results were compared with those from controls without known abuse of ethanol. The relative numbers of fibers were the same in two groups, but the size of the fast-twitch-glycolytic (white) fibers was diminished in the alcoholic group. The activities of TPD and LD were diminished in skeletal muscle of the alcoholics. This is most probably caused by the reduced amount of fast-twitch-glycolytic tissue, as there was a good correlation between this amount and the activity of the two enzymes. The activity of cytox was slightly lower in muscle of the alcoholics than in that of the controls. The volume fraction of mitochondria was lower in the alcoholic group than in the control group. Volume fractions of fat and fibrillar and extrafibrillar space were equal in the two groups. No significant differences were found in the amount of glycogen and ATP in the muscle of the two groups. However, the content of creatine phosphate is higher in the alcoholic group than in the control group.
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PMID:Effects of chronic ethanol abuse on structure and enzyme activities of skeletal muscle in man. 17 13

The tetrameric glyceraldehyde-3-phosphate dehydrogenase from rabbit muscle binds NAD+ and some of its analogues in a negatively cooperative manner, whereas other NAD+ analogues bind non-cooperatively to this enzyme. Subsequent to alkylation of a fraction of the active sites of the enzyme with the fluorescent SH reagent N-iodoacetyl-N'-(5-sulfo-1-naphthyl)-ethylenediamine, it was found that the alkylated sites bind NAD+ and NAD+ analogues with a markedly reduced affinity as compared with non-alkylated sites. It was therefore feasible to measure the fluorescence and the circular polarization of the luminescence of the enzyme-bound alkyl groups as a function of binding of NAD+ and of NAD+ analogues to the non-alkylated sites. The changes observed indicate that ligand binding to the non-alkylated sites induces changes in the fluorescence properties of the alkyl groups bound to neighbouring subunits, most likely through the protein moiety. The nature of these changes appears to depend on the structure of the coenzyme analogue. The binding of the non-cooperative binders acetyl-pyridine--adenine dinucleotide, ATP and ADP-ribose induce different conformational changes in the neighbouring vacant subunit, as monitored by the spectroscopic properties of the bound alkyl group. These results in conjunction with other data support the view that the negative cooperativity in NAD+ binding to glyceraldehyde-3-phosphate dehydrogenase results from ligand-induced conformational changes. Furthermore, these results further support the view that subtle structural changes in the coenzyme molecule determine the nature of the conformational changes induced within the enzyme tetramer.
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PMID:Evidence for ligand-induced conformational changes in rabbit-muscle glyceraldehyde-3-phosphate dehydrogenase. 22 43

The amino acid sequence of ATP phosphoribosyltransferase [1-(5'-phosphoribosyl)-ATP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.17] of Salmonella typhimurium has been determined. The amino acid sequence analysis was carried out with a combination of manual and automated methods. It was complemented by DNA sequence analysis (done in another laboratory) of the hisG gene, which codes for it. The subunit polypeptide chain contains 299 amino acid residues and has a molecular weight of 33,216. The amino-terminal segment of the protein is relatively basic in character and has limited sequence homologies with the lac repressor and histidinol dehydrogenase. In addition, the protein contains a 40-residue segment that has 13 residues identical with the sequence surrounding the active-site cysteine of glyceraldehyde-3-phosphate dehydrogenase.
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PMID:Amino acid sequence of ATP phosphoribosyltransferase of Salmonella typhimurium. 37 78

Glycerolization of freshly collected human erythrocytes leads to a reduction in ATP levels which return to their original values following deglycerolization. The reduction in ATP levels is largely prevented by pyruvate but not by inosine and glucose, singly or in combination. This implies that the ATP lesion associated with glycerolization reflects mainly a decrease in the NAD/NADH ratio and accordingly a reduced glyceraldehyde-3-phosphate dehydrogenase activity. 2,3-DPG levels were not influenced by glycerolization and deglycerolization. Erythrocytes depleted of ATP in the presence of glycerol can have their ATP levels repleted by either pyruvate or inosine, but require the presence of both compounds for maintenance during a post-rejuvenation incubation period. This indicates that the prolonged presence of glycerol influences both the NAD/NADH ratio and the carbon-containing intermediates of glycolysis. Glycerol did not influence ATP repletion of erythrocytes stored at 4 degrees C for 20 days by inosine in combination with pyruvate, but substantially decreased the repletion of their 2,3-DPG levels.
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PMID:Influence of glygerol on ATP and 2,3-DPG levels of human erythrocytes. 46 14


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