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)

Ultraviolet resonance Raman (UVRR) spectra, with 260-nm excitation, are reported for oxidized and reduced nicotinamide adenine dinucleotides (NAD+ and NADH, respectively). Corresponding spectra are reported for these coenzymes when bound to the enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and liver and yeast alcohol dehydrogenases (LADH and YADH). The observed differences between the coenzyme spectra are interpreted in terms of conformation, hydrogen bonding, and general environment polarity differences between bound and free coenzymes and between coenzymes bound to different enzymes. The possibility of adenine protonation is discussed. UVRR spectra with 220-nm excitation also are reported for holo- and apo-GAPDH (GAPDH-NAD+ and GAPDH alone, respectively). In contrast with the 260-nm spectra, these show only bands due to vibrations of aromatic amino acid residues of the protein. The binding of coenzyme to GAPDH has no significant effect on the aromatic amino acid bands observed. This result is discussed in the light of the known structural change of GAPDH on binding coenzyme. Finally, UVRR spectra with 240-nm excitation are reported for GAPDH and an enzyme-substrate intermediate of GAPDH. Perturbations are reported for tyrosine and tryptophan bands on forming the acyl enzyme.
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PMID:An ultraviolet resonance Raman study of dehydrogenase enzymes and their interactions with coenzymes and substrates. 265 94

Controlled oxidation of rat muscle glyceraldehyde-3-phosphate dehydrogenase (GPDH) was carried out in an attempt to stimulate age-related effects observed in enzyme samples purified from old animals. A comparative study of the "simulated aged" and of native young and old GPDH forms was done using fluorescence techniques. The present work is based on our previous findings that the locus of the age-related modifications in GPDH is in the nicotinamide-binding site, where the catalytically active Cys-149 residue is located, and that an increase in oxidation potential occurs in old animal tissues which may enable various oxidizing agents to play a significant role in the inactivation of certain enzymes. Thus it has been suggested that the loss of specific activity observed in old GPDH may be due to subtle and irreversible conformational changes caused by reaction of Cys-149 with these agents. The circularly polarized luminescence (CPL) spectrum emitted by the fluorescent sulfhydryl reagent I-AEDANS covalently bound to GPDH through Cys-149 at the nicotinamide binding site, revealed a significant difference in conformation between these sites in young and old GPDH forms. Large differences were also observed between corresponding spectra when the binding sites were saturated with NAD+, reflecting the development of marked conformational changes in both young and old GPDH species upon coenzyme binding. The oxidizing reagents employed in the current study (hydrogen peroxide, superoxide radical and atmospheric dioxygen) are all expected to be more commonly encountered in the less reducing environment of old animal tissues. All of them, though to a different extent, caused a significant inactivation of the enzyme dependent on the initial oxidant concentration. Although the original enzymatic activity could be partially restored by incubation with a reducing agent, the prior oxidation was found to induce some irreversible structural changes as expressed in a decrease in the number of fast reacting SH groups. The extent of irreversible inactivation was a function of both oxidant concentration and the duration of exposure to the oxidant. The affinity of the oxidized GPDH species (termed "aged") toward coenzyme, as monitored by fluorometric titrations, was markedly lower than that observed for both the native young and old GPDHs. In addition, the CPL spectra of the "aged" enzymes were different from those obtained for both native forms.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Mechanism of aging of rat muscle glyceraldehyde-3-phosphate dehydrogenase studied by selective enzyme-oxidation. 282 73

The experimental results summarized here suggest a mechanism of oxidant induced cell injury which begins with the generation of DNA strand breaks. The mechanism of the generation of these breaks is currently under investigation. The presence of DNA strand breaks activates pADPr polymerase which causes the conversion of cellular NAD to pADPr and free nicotinamide. It is likely that low levels of NAD are associated with inhibition of glycolysis and thereby contribute to the oxidant-induced fall in cell ATP. Additional factors are likely to contribute to altered cell metabolism following oxidant injury. Hyslop has shown that the Vmax of a critical enzyme of the glycolytic pathway, glyceraldehyde-3-phosphate dehydrogenase, is decreased following exposure to oxidant. Finally, it is likely that the oxidative phosphorylation functions of the mitochondrial membrane may also be perturbed by oxidant injury. The extent to which these alterations in cell metabolism occur in vivo following exposure to oxidants may be of great importance to our understanding of acute inflammatory tissue injury.
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PMID:Oxidant injury of cultured cells: biochemical consequences. 311 91

The structure of apo-glyceraldehyde-3-phosphate dehydrogenase (GAPDHase) from Bacillus stearothermophilus has been refined using a restrained least-squares method. The final crystallographic R-factor is 0.177 for all 53,315 reflections between 7.0 and 2.5 A. The resulting model has been analysed with respect to lattice interactions, molecular symmetry, temperature factors and solvent structure showing that, apart from local deviations due to intermolecular contact, the molecule exhibits a very high degree of local 222 symmetry. Analysis of differences between the structure of apo-GAPDHase and the previously refined holo-GAPDHase at 1.8 A resolution reveals details of conformational change in the enzyme induced by cofactor binding. The change, which was previously described as a rigid-body rotation of the coenzyme-binding domain with respect to the catalytic domain, is of more complex nature and involves relative shifts of several structural elements in the coenzyme-binding domain and some small changes in the catalytic domain. A possible mechanism of this conformational change is proposed based on the comparison of the refined structures and model-building studies. According to this mechanism, the adenosine moiety of NAD can initially bind to the protein in the apo-enzyme conformation. Several attractive interactions resulting from the initial binding of the coenzyme trigger conformational changes in the molecule of GAPDHase that: (1) create the productive nicotinamide-moiety binding site; (2) improve enzyme-coenzyme interactions at the adenosine moiety; (3) modify the active site to optimize the positioning of catalytic residues and ion-binding sites. Implications of the proposed mechanism for existing experimental data on binding of NAD analogues to GAPDHase are discussed.
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PMID:Coenzyme-induced conformational changes in glyceraldehyde-3-phosphate dehydrogenase from Bacillus stearothermophilus. 321 Feb 37

Inhibition of ADP phosphorylation by both glycolysis and mitochondria in P388D1 cells exposed to H2O2 is described. Net glucose uptake and lactate production were inhibited by oxidant exposure (ED50 = 50-100 microM). Glycolysis was specifically inactivated at the glyceraldehyde-3-phosphate dehydrogenase step by three independent mechanisms: (a) direct inactivation of the intracellular enzyme (ED50 approximately equal to 100 microM); (b) reduction of the intracellular concentration and redox potential of its nicotinamide cofactors; and (c) a cytosolic pH shift further from the enzyme optima. Consistent with inhibition of glycolysis at the glyceraldehyde-3-phosphate dehydrogenase step, a rise in the intracellular concentration of glyceraldehyde 3-phosphate, dihydroxyacetone phosphate, and fructose 1,6-bisphosphate was observed. The calculated combined inhibition of glyceraldehyde-3-phosphate dehydrogenase activity could be reasonably correlated with the depression in glycolytic flux rate with the appropriate modeling. The steady-state contribution by mitochondria to the total intracellular ATP pool was indirectly determined by the use of various metabolic inhibitors and was found to rapidly decline following exposure to 300-800 microM H2O2. The inhibition of ADP phosphorylation appeared to be related more to the direct inhibition of the ATPase-synthase complex rather than to the diminished capacity of the respiratory chain for coupled electron transport. Both the estimated rates of ADP phosphorylation by glycolysis and mitochondria and the estimated rate of ATP hydrolysis by ongoing metabolism were utilized to model the approximate decline in intracellular ATP expected at 15-min exposure to various H2O2 concentrations. Theoretical calculations and the measured intracellular ATP status were in good agreement. Oxidant exposure for 15 min resulted in dose-dependent killing of the cells (ED50 = 500 microM), indicating a close correlation between H2O2-mediated loss of intracellular ATP and cell viability. The possible contribution of impaired energy homeostasis during oxidant-mediated injury to the process of cell dysfunction and death is discussed.
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PMID:Mechanisms of oxidant-mediated cell injury. The glycolytic and mitochondrial pathways of ADP phosphorylation are major intracellular targets inactivated by hydrogen peroxide. 333 86

The tetrameric molecule of glyceraldehyde-3-phosphate dehydrogenase possesses the ability to bind fluorescent probes of cationic nature (auramine O and acridine orange) outside the active center. The rabbit skeletal muscle and yeast enzymes share some common features, e.g., the conformational non-equivalency of subunits; two subunits per tetramer can bind auramine O; conformational changes caused by the binding of adenyl mononucleotides and involving the microenvironment of auramine O binding sites; the ability to bind the cationic probe at pH values typical for the maximal activity of the enzyme in the reaction of glyceraldehyde 3-phosphate oxidation. The yeast and rabbit muscle enzymes are distinguished in terms of localization of the probe binding sites with respect to the active center and/or in the nature of conformational changes induced by NAD+ binding. It was demonstrated that nicotinamide mononucleotide may serve as a co-enzyme in glyceraldehyde 3-phosphate oxidation catalyzed by yeast dehydrogenase; this reaction in inhibited by AMP.
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PMID:[Comparative study of glyceraldehyde-3-phosphate dehydrogenases isolated from rabbit skeletal muscles and baker's yeast using cationic fluorescent probes]. 353 63

Gluteal muscle specimens were taken from 4 horses. From 1 of the 4 gluteal muscles, serial sections were prepared. Individual muscle fibers were identified and studied, using photomicrographs of sections stained by different enzyme histochemical methods. In specimens in which cytoplasmic soluble enzymes were studied, use was made of the semi-permeable membrane technique to hamper enzyme diffusion into reaction fluids. Enzymes involved in glycogenolysis, glycolysis, the tricarboxylic acid cycle, synthesis of reduced nicotinamide adenine dinucleotide phosphate, the pentose phosphate cycle, the alpha-glycerolphosphate shuttle, the respiratory chain, catabolism, and muscular contraction were studied. Some key enzymes of different metabolic pathways were also included. Each of 3 fiber types identified had distinct features. Type I fibers were characterized by a relatively strong aerobic capacity, compared with type IIA fibers, which were more glycolytic and had strong aerobic and moderate-to-strong anaerobic capacity. Type IIB fibers were characterized by a relatively low aerobic and a relatively high anaerobic capacity, and were glycolytic. Activities of phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, and alpha-naphtylesterase (nonspecific esterase) were so markedly different in the 3 fiber types that fiber typing was possible, aided by the demonstration of the activities of these enzymes. In type IIB fibers, the pentose phosphate cycle was more important than in the other fiber types. Except for the unexplained high alpha-naphtylesterase activity in type IIB fibers, catabolic enzymes were not active in healthy equine muscle fibers.
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PMID:Enzyme histochemical features of equine gluteus muscle fibers. 403 4

By competition with lactate dehydrogenase (LDH) for nicotinamide adenine dinucleotide (NAD), commonly occurring intracellular proteins, such as glyceraldehyde-3-phosphate dehydrogenase, malate dehydrogenase, and albumin, can protect LDH-1 and LDH-5 from inhibition and ternary complex formation with NAD and pyruvate. The existence of intracellular proteins that compete with LDH for NAD renders unphysiological a model for estimating the extent of intracellular LDH inhibition based on incubations of only LDH, NAD, and pyruvate.
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PMID:Lactate dehydrogenase isozymes: further kinetic studies at high enzyme concentration. 431 48

The rate coefficient for (22)Na release from previously labeled human erythrocytes was determined in the presence of 0.1-10 mM sodium fluoride (F). The oxidized nicotinamide adenine dinucleotide (NAD(+)) level at the end of 2 hr of incubation in tris(hydroxymethyl)aminomethane (Tris)-Ringer medium was also measured. Both parameters decreased proportionately as F concentration was raised. Both F-induced changes were immediate and were reversed by 10 mM pyruvate. The decrease in NAD(+) concentration following enolase inhibition by F is attributed to a diminished rate of formation in the reaction catalyzed by lactic dehydrogenase (LDH) with undiminished continued utilization in the reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase (GAPDH). It is postulated that the NAD(+) lowering limited the GAPDH step, resulting in proportionate decreases in the rates of phosphoglycerate kinase (PGK) and Na,K-dependent adenosine triphosphatase (Na,K-ATPase), a reaction sequence thought to link glycolysis with active Na extrusion. Adding pyruvate with F increased NAD(+) production at the LDH step, thus reactivating GAPDH, PGK, and Na,K-ATPase and leading to the observed restoration of (22)Na release. The results suggest, therefore, that F inhibits active Na transport in intact human erythrocytes indirectly through a lowering of NAD(+), although, direct inhibition of the Na,K-ATPase by F may possibly occur simultaneously.
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PMID:The role of oxidized nicotinamide adenine dinucleotide in fluoride inhibition of active sodium transport in human erythrocytes. 434 51

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.
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PMID:Glucose catabolism in Micrococcus sodonensis. 438 30


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