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:4.1.2.13 (aldolase)
3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A simple, rapid enzymatic assay for the determination of inorganic pyrophosphate in tissue and plasma has been developed using the enzyme pyrophosphate--fructose-6-phosphate 1-phosphotransferase (EC 2.7.1.90) which was purified from extracts of Propionibacterium shermanii. The enzyme phosphorylates fructose-6-phosphate to produce fructose-1,6-bisphosphate using inorganic pyrophosphate as the phosphate donor. The utilization of inorganic pyrophosphate is measured by coupling the production of fructose-1,6-bisphosphate with the oxidation of NADH using fructose-bisphosphate aldolase (EC 4.1.2.13), triosephosphate isomerase (EC 5.3.1.1), and glycerol-3-phosphate dehydrogenase (NAD+)(EC 1.1.1.8). The assay is completed in less than 5 min and is not affected by any of the components of tissue or plasma extracts. The recovery of pyrophosphate added to frozen tissue powder was 97 +/- 1% (n = 4). In this assay the change in absorbance is linearly related to the concentration of inorganic pyrophosphate over the curvette concentration range of 0.1 microM to 0.1 mM.
...
PMID:A rapid, enzymatic assay for the measurement of inorganic pyrophosphate in animal tissues. 976 43

The effect of hypoxia on the levels of glycogen, glucose and lactate as well as the activities and binding of glycolytic and associated enzymes to subcellular structures was studied in brain, liver and white muscle of the teleost fish, Scorpaena porcus. Hypoxia exposure decreased glucose levels in liver from 2.53 to 1.70 mumol/g wet weight and in muscle led to its increase from 3.64 to 25.1 mumol/g wet weight. Maximal activities of several enzymes in brain were increased by hypoxia: hexokinase by 23%, phosphoglucoisomerase by 47% and phosphofructokinase (PFK) by 56%. However, activities of other enzymes in brain as well as enzymes in liver and white muscle were largely unchanged or decreased during experimental hypoxia. Glycolytic enzymes in all three tissues were partitioned between soluble and particulate-bound forms. In several cases, the percentage of bound enzymes was reduced during hypoxia; bound aldolase in brain was reduced from 36.4 to 30.3% whereas glucose-6-phosphate dehydrogenase fell from 55.7 to 28.7% bound. In muscle PFK was reduced from 57.4 to 41.7% bound. Oppositely, the proportion of bound aldolase and triosephosphate isomerase increased in hypoxic muscle. Phosphoglucomutase did not appear to occur in a bound form in liver and bound phosphoglucomutase disappeared in muscle during hypoxia exposure. Anoxia exposure also led to the disappearance of bound fructose-1,6-bisphosphatase in liver, whereas a bound fraction of this enzyme appeared in white muscle of anoxic animals. The possible function of reversible binding of glycolytic enzymes to subcellular structures as a regulatory mechanism of carbohydrate metabolism is discussed.
...
PMID:Effect of hypoxia on the activity and binding of glycolytic and associated enzymes in sea scorpion tissues. 977 12

Axenic cultures of Suillus bovinus were cultivated in inorganic liquid medium with glucose as a carbon source at 25 degrees C and continuous supply of oxygen by aeration with compressed air in the dark. Exogenous fructose as sole carbon source yielded about 50% less increase in dry weight than glucose. This resulted from different uptake velocities. Sucrose as sole exogenous carbon source yielded no measurable increase in dry weight. In glucose cultures, activities of all glycolytic enzymes were found. Maximum specific activities varied largely (from about 60 [fructose 6-phosphate kinase] to about 20,000 [triosephosphate isomerase] nmoles.mg protein-1.min-1). Apparent K(m)-values also varied over more than two orders of magnitude (0.035 mM [pyruvate kinase] to 6.16 mM [triosephosphate isomerase]). Fructose 6-phosphate kinase proved to be the fructose 2,6-bisphosphate-regulated type, aldolase the divalent cation-dependent (class II) type and glyceratephosphate mutase the glycerate 2,3-phosphate-independent type of the respective enzymes. Eight of the 10 enzymes exhibited pH-optima between 7.5-8.0. Triosephosphate isomerase and pyruvate kinase showed highest activities at pH 6.5. Regulatory sites within the glycolytic pathway of Suillus bovinus are discussed; fructose 6-phosphate kinase appears to be its main bottle neck.
...
PMID:Complete sequence of glycolytic enzymes in the mycorrhizal basidiomycete, Suillus bovinus. 982 41

Based on the neurotrophic properties of astrocytes in response to ischemia, the current work focuses on the mechanism for cultured astrocytes to adapt to a hypoxic environment. Intracellular glucose levels in primary cultured rat astrocytes exposed to hypoxia fell by 30% within 24 h, in parallel with a decrease in glycogen stores. Glycolytic metabolism was crucial for cell survival during hypoxia, as 2-deoxyglucose resulted in rapid ATP depletion and cell death. The mechanism for maintaining glucose levels under these conditions appeared to be mobilization of glycogen stores, rather than increased extracellular uptake of glucose, as gluconolactone (an inhibitor of beta1-4 amyloglucosidase) induced a rapid fall in cellular ATP in cultures subjected to hypoxia, whereas cytochalasin B was without affect. Addition of cycloheximide diminished the viability of astrocytes in hypoxia, suggesting an obligatory role of de-novo gene expression to respond to hypoxia. Consistently, the results of differential display suggested the induction of glycolytic enzymes, including aldolase A (EC 4.1.2.13), hexokinase II (ATP: D-hexose 6-phosphotransferase, EC 2.7.1.1), and triosephosphate isomerase (EC 5.3.1.1) in the hypoxic culture. Marked induction of these glycolytic enzymes in hypoxic astrocytes was confirmed by Northern blot analysis. These data provide a theoretical basis to understand the ability of astrocytes to tolerate ischemic condition.
...
PMID:Exposure of cultured primary rat astrocytes to hypoxia results in intracellular glucose depletion and induction of glycolytic enzymes. 1064 Jun 73

Whole cell lysates of pathogenic and nonpathogenic strains of Cryptobia salmositica were subjected to subcellular fractionation using differential and isopycnic centrifugation in sucrose. The glycolytic enzymes hexokinase, fructose-1,6-biphosphate aldolase, triosephosphate isomerase, glucosephosphate isomerase and glyceraldehyde-3-phosphate-dehydrogenase and the peroxisomal enzyme catalase were associated with a microbody that had a buoyant density in sucrose of 1.21 g cm-3. Lactate dehydrogenase was detected in whole cell lysates, but not in purified organelles. A microbody with a positive reaction for catalase was detected in electron microscope sections of the pathogenic and nonpathogenic strains. These catalase-containing microbodies fused with lipid bodies and vacuoles, arose by division from pre-existing microbodies and expelled their contents into the cytoplasm of the cell. Both strains also modified the catalase content in their microbodies. Under aerobic conditions, they metabolized glucose to pyruvate and lactate. We conclude that part of the glycolytic pathway in C. salmositica is compartmentalized in a microbody called the glycosome.
...
PMID:Identification of glycosomes and metabolic end products in pathogenic and nonpathogenic strains of Cryptobia salmositica (Kinetoplastida: Bodonidae). 1098 44

This paper presents a modified method of enzymatic assay for Fructose-1,6-diphosphate(FDP). FDP is split to dihydroxyacetone phosphate (DAP) and glyceraldehyde-3-phosphate (GAP) by the action of aldolase. DAP is hydrolyzed at room temperature to free triose. Under alkaline conditions, the free triose is reacted with 2,4-dinitrophenylhydrazine (DNPH), yielding a 2,4-dinitrophenylhydrazine derivative which dissolve in alkali forming a purple color mixture, with maximum absorption at 540.nm. It is proportional to the contents of FDP. Because the method depends on the colorimetric determination of triose formed from fructose-1,6-diphosphate only by aldolase, glycerophosphate dehydrogenase/triosephosphate isomerase (GDH/TIM) and reduced nicotinamide adenine dinucleotide (NADH) which usually applied in multienzymatic method, are omitted in the modified method. The method is specific, convenient and accuracy for the determination of FDP.
...
PMID:[Determination of fructose-1,6-diphosphate with aldolase-DNPH by the colorimetric method]. 1128 59

Paracoccidioides brasiliensis is a fungal pathogen of humans. To identify antigens from P. brasiliensis we fractionated a crude preparation of proteins from the fungus and detected the IgG reactive proteins by immunoblot assays of yeast cellular extracts with sera of patients with paracoccidioidomycosis (PCM). We identified and characterized six new antigens by amino acid sequencing and homology search analyses with other proteins deposited in a database. The newly characterized antigens were highly homologous to catalase, fructose-1,6-biphosphate aldolase (aldolase), glyceraldehyde-3-phosphate dehydrogenase, malate dehydrogenase and triosephosphate isomerase from several sources. The characterized antigens presented preferential synthesis in yeast cells, the host fungus phase.
...
PMID:Two-dimensional electrophoresis and characterization of antigens from Paracoccidioides brasiliensis. 1141 27

Phosphofructokinase-1 plays a key role in the regulation of carbohydrate metabolism. Its activity can be used as an indicator of the glycolytic flux in a tissue sample. The method most commonly employed to determine phosphofructokinase-1 activity is based on oxidation of NADH by the use of aldolase, triosephosphate isomerase, and alpha-glycerophosphate dehydrogenase. This method suffers from several disadvantages, including interactions of the auxiliary enzymes with phosphofructokinase-1. Other methods that have been used also require auxiliary enzymes or are less sensitive than a coupled assay. Here, we propose a direct method to determine phosphofructokinase-1 activity, without the use of auxiliary enzymes. This method employs fructose-6-phosphate and ATP labeled with 32P in the gamma position ([gamma-32P]ATP), and leads to the formation of ADP and fructose-1,6-bisphosphate labeled with 32P ([1-32P]fructose-1,6-bisphosphate). Activated charcoal is used to adsorb unreacted [gamma-32P]ATP, and the radioactive product in the supernatant, [1-32P]fructose-1,6-bisphosphate, is analyzed on a liquid scintillation counter. The proposed method is precise and relatively inexpensive, and can be applied to determine phosphofructokinase-1 activity in cellular extracts as well as in the purified enzyme.
...
PMID:A radioassay for phosphofructokinase-1 activity in cell extracts and purified enzyme. 1174 2

Formation of mixed disulfides between glutathione and the cysteines of some proteins (glutathionylation) has been suggested as a mechanism through which protein functions can be regulated by the redox status. The aim of this study was to identify the proteins of T cell blasts that undergo glutathionylation under oxidative stress. To this purpose, we radiolabeled cellular glutathione with (35)S, exposed T cells to oxidants (diamide or hydrogen peroxide), and performed nonreducing, two-dimensional electrophoresis followed by detection of labeled proteins by phosphorimaging and their identification by mass spectrometry techniques. We detected several proteins previously not recognized to be glutathionylated, including cytoskeletal proteins (vimentin, myosin, tropomyosin, cofilin, profilin, and the already known actin), enzymes (enolase, aldolase, 6-phosphogluconolactonase, adenylate kinase, ubiquitin-conjugating enzyme, phosphoglycerate kinase, triosephosphate isomerase, and pyrophosphatase), redox enzymes (peroxiredoxin 1, protein disulfide isomerase, and cytochrome c oxidase), cyclophilin, stress proteins (HSP70 and HSP60), nucleophosmin, transgelin, galectin, and fatty acid binding protein. Based on the presence of several protein isoforms in control cells, we suggest that enolase and cyclophilin are heavily glutathionylated under basal conditions. We studied the effect of glutathionylation on some of the enzymes identified in the present study and found that some of them (enolase and 6-phosphogluconolactonase) are inhibited by glutathionylation, whereas the enzymatic activity of cyclophilin (peptidylprolyl isomerase) is not. These findings suggest that protein glutathionylation might be a common mechanism for the global regulation of protein functions.
...
PMID:Identification by redox proteomics of glutathionylated proteins in oxidatively stressed human T lymphocytes. 1190 14

To establish a way to control or to decrease the daily increasing concentration of atmospheric CO(2), metabolically engineering Cyanobacteria was taken for the improvement of its efficiency of photosynthetic CO(2) fixation. As a preliminary stage of this study, three genes coding for three important Calvin cycle enzymes, i.e. triosephosphate isomerase (TPI), fructose-1, 6-bisphosphate aldolase(FBP aldolase),and fructose-1, 6-bisphosphatase(FBPase), respectively, have been cloned into one plasmid, pTrcFAT, which is controlled by promoter trc. Successful co-transcriptional expression of these three genes resulted inhigh yields of these enzymes under the induction of 0.25 mmol/L IPTG. Bioassay showed that the expressed enzymes from one liter of culture could directly catalyze DHAP conversion into 700 &mgr;mol of fructose-6-phosphate (F-6-P) per one minute. Furthermore, in order to introduce the three genes co-expression system into Cyanobacteria, a shuttle plasmid between E.coli and Cyanobacteria was constructed using plasmid pTrcFAT and a shuttle vector pDC-8, forming ashuttle plasmid pDCFAT-2 containing a dimer of the three genes co-expression operator. Successful co-expression in E.coli of pDCFAT-2 with higher full activity has been obtained. This shuttle was used to transform of Cyanobacteria Synechococcus sp. PCC 7942, and a few positive colonies were obtained.
...
PMID:Co-expression of Triosephosphate Isomerase, Fructose-1, 6-bisphosphate Aldolase and Fructose-1, 6-bisphosphatase in E.coli. 1205 3


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---