Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A blotting method is described to detect enzymes that do not normally yield a colored product. The method can be used for dot blotting as well as blotting after gel electrophoresis of many enzymes if the reactions they catalyze can be coupled to an oxidase or a dehydrogenase. The latter, designated "auxiliary enzymes," are preimmobilized on membranes of nitrocellulose or positively charged nylon and the reaction they catalyze is coupled with reduction of tetrazolium salt to yield colored formazan on areas of the transfer membrane occupied by the blotted enzymes. In the examples reported here, preimmobilized glucose oxidase, L-amino acid oxidase, xanthine oxidase, malate dehydrogenase, and a mixture of hexokinase and glucose-6-phosphate dehydrogenase were used as auxiliary enzymes to detect blotted invertase, leucine aminopeptidase, purine nucleoside phosphorylase, fumarase, and adenylate kinase, respectively. Detection limits varied, but never exceeded 100 ng for these enzymes. After blotting from polyacrylamide gels, the fumarase assay was the most sensitive of those investigated, detecting 10 ng of enzyme used for electrophoresis. Invertase, a glycoprotein, was detected with higher sensitivity on nitrocellulose membranes when concanavalin A was present on the membrane in addition to the auxiliary enzyme, glucose oxidase. On blots from isoelectric focusing gels, the assay detected two isozymes of purine nucleoside phosphorylase in a sample from calf spleen and at least five isozymes of this enzyme in lysates from human red cells.
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PMID:Activity staining of blotted enzymes by reaction coupling with transfer membrane-immobilized auxiliary enzymes. 245 38

The equilibrium precipitation by polyethyleneglycol of alcohol dehydrogenase, fumarase and invertase from Saccharomyces cerivisiae has been studied. The precipitation can often be represented by a simple linear equation analogous to Cohn's equation for salting-out: log S = X-a x C where S is the protein solubility and C the concentration of polymer, X and a are constants. A more complex form of the equation log S + fS = X-a x C where f is a protein self-interaction coefficient, is sometimes necessary, particularly at high protein concentrations and at pH values distant from the isoelectric point. Protein solubility with respect to polyethyleneglycol is influenced by temperature and ionic strength and particularly by pH and protein concentration. Different results were obtained by discrete and sequential addition of polyethyleneglycol. Effective fractional separation of the enzymes is restricted to protein concentrations below about 10 mg/ml.
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PMID:The precipitation of enzymes from cell extracts of Saccharomyces cerevisiae by polyethyleneglycol. 1999 33

1. Electron microscopic studies of the sieve tube sap obtained from the secondary phloem of Robinia pseudoacacia by the method of Hartig (1860) showed the presence of well developed mitochondria in addition to membrane fragments. 2. In this sieve tube sap the following enzymes could be detected qualitatively: UTP-glucose-1-phosphate-uridyl transferase, UDPG-fructose glucosyl transferase, glucose-6-phosphate dehydrogenase, hexokinase (for glucose and fructose), phosphohexose isomerase, phosphofructokinase, and UDPG-pyrophosphatase. 3. The following enzymes were determined quantitatively: phosphorylase, amylase, aldolase, triosephosphate isomerase, NAD(+)-dependent glyceraldehyde-3-phosphate dehydrogenase, phosphoglyceromutase, enolase, pyruvate kinase, pyruvate decarboxylase, alcohol dehydrogenase, isocitrate dehydrogenase, fumarase, malate dehydrogenase, glutamate-pyruvate transaminase, glutamate dehydrogenase, glutamate-oxalacetate transaminase, and anorganic pyrophosphatase. 4. The following enzymes could not be detected: UDGP dehydrogenase, UDPG-fructose-6-phosphate-glucosyltransferase, invertase, phosphoglucomutase, lactate dehydrogenase, and citrate synthase. 5. The enzyme pattern in the sieve tube saps of Tilia platyphyllos, Carpinus betulus, Fraxinus americana, Quercus borealis maxima, and Salix viminalis is qualitatively similar to that of Robinia, but shows quantitative differences (as far as analyzed). 6. The meaning of the results for the metabolism and function of the sieve tubes in situ is discussed.
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PMID:[Enzyme activities in the sieve tube sap of Robinia pseudoacacia L. and of other tree species]. 2449 58

Central metabolism is a coordinated network that is regulated at multiple levels by resource availability and by environmental and developmental cues. Its genetic architecture has been investigated by mapping metabolite quantitative trait loci (QTL). A more direct approach is to identify enzyme activity QTL, which distinguishes between cis-QTL in structural genes encoding enzymes and regulatory trans-QTL. Using genome-wide association studies, we mapped QTL for 24 enzyme activities, nine metabolites, three structural components, and biomass in Arabidopsis thaliana We detected strong cis-QTL for five enzyme activities. A cis-QTL for UDP-glucose pyrophosphorylase activity in the UGP1 promoter is maintained through balancing selection. Variation in acid invertase activity reflects multiple evolutionary events in the promoter and coding region of VAC-INVcis-QTL were also detected for ADP-glucose pyrophosphorylase, fumarase, and phosphoglucose isomerase activity. We detected many trans-QTL, including transcription factors, E3 ligases, protein targeting components, and protein kinases, and validated some by knockout analysis. trans-QTL are more frequent but tend to have smaller individual effects than cis-QTL. We detected many colocalized QTL, including a multitrait QTL on chromosome 4 that affects six enzyme activities, three metabolites, protein, and biomass. These traits are coordinately modified by different ACCELERATED CELL DEATH6 alleles, revealing a trade-off between metabolism and defense against biotic stress.
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PMID:Genome-Wide Association Mapping Reveals That Specific and Pleiotropic Regulatory Mechanisms Fine-Tune Central Metabolism and Growth in Arabidopsis. 2895 12