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)

Six and twelve hours after a single i.p. dose of cyclophosphamide (100 mg/kg body weight) the activity of different "brush border enzymes" (maltase, sucrase lactase, alkaline phosphatase, gamma-glutamyl transferase) and of a lysosomal enzyme (acid phosphatase) did not change. In vivo absorption of galactose was not diminished by the treatment. The pattern of response to cyclophosphamide seems to be different in SPF and GF rats. The response of crypt epithelium (cell number, mitotic number, mitotic frequency) was more pronounced in the SPF rats, whereas the villus height only decreased in the GF rats.
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PMID:Morphology and enzyme aktivity in rat small intestinal epithelium 6 and 12 hrs. after an alkylating agent (cyclophosphamide). 1 Jul 11

The degrees of autolysis attained by five different genera of filamentous fungi during an incubation period of 60 days, under the same culture conditions were: 87.3% for Penicillium oxalicum; 65.9% for Neurospora crassa; 62.7% for Polystictus versicolor; 51.7% for Aspergillus niger and 23.5% for Nectria galligena. N. crassa, A. niger and P. versicolor reached the end of the autolysis during this incubation period (60 days), whereas P. oxalicum and N. galligena did not. The excretion of the lytic enzymes beta-N-acetylglucosaminidase, beta -1-3 glucanase, chitinase, invertase and acid phosphatase into the culture medium during growth and autolysis was investigated. The excretion of these enzymes was consistent with the degree of autolysis reached, the maximum excretion belonging to P. oxalicum and the minimum to N. galligena. The N. crassa invertase was excreted into the culture liquid at levels very much higher than the other enzymes studied, and at levels very much higher than the invertases excreted by the other fungi.
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PMID:Lytic enzymes in the autolysis of filamentous fungi. 1 4

A procedure was developed for the analytical isolation of brush border and basal lateral plasma membranes of intestinal epithelial cells. Brush border fragments were collected by low speed centrifugation, disrupted in hypertonic sorbitol, and subjected to density gradient centrifugation for separation of plasma membranes from nuclei and core material. Sucrase specific activity in the purified brush border plasma membranes was increased fortyfold with respect to the initial homogenate. Basal lateral membrane were harvested from the low speed supernatant and resolved from other subcellular components by equilibrium density gradient centrifugation. Recovery of Na, K-ATPase activity was 94%, and 61% of the recovered activity was present in a single symmetrical peak. The specific activity of Na, K-ATPase was increased twelvefold, and it was purified with respect to sucrase, succinic dehydrogenase, NADPH-cytochrome c reductase, nonspecific esterase, beta-glucuronidase, DNA, and RNA. The observed purification factors are comparable to results reported for other purification procedures, and the yield of Na, K-ATPase is greater by a factor of two than those reported for other procedures which produce no net increase in the Na, K-ATPase activity. Na, K-ATPase rich membranes are shown to originate from the basal lateral plasma membranes by the patterns of labeling that were produced when either isolated cells or everted gut sacs were incubated with the slowly permeating reagent 35S-p-(diazonium)-benzenesulfonic acid. In the former case subsequently purified Na, K-ATPase rich and sucrase rich membranes are labeled to the same extent, while in the latter there is a tenfold excess of label in the sucrase rich membranes. The plasma membrane fractions were in both cases more heavily labeled than intracellular protein. Alkaline phosphatase and calcium-stimulated ATPase were present at comparable levels on the two aspects of the epithelial cell plasma membrane, and 25% of the acid phosphatase activity was present on the basal lateral membrane, while it was absent from the brush border membrane. Less than 6% of the total Na, K-ATPase was present in brush border membranes.
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PMID:Analytical isolation of plasma membranes of intestinal epithelial cells: identification of Na, K-ATPase rich membranes and the distribution of enzyme activities. 13 16

The two mutants (abs) and (wal) affecting the cell morphology of yeast lead also to higher in vivo activities of the cell wall enzymes acid phosphatase, invertase and melibiase.
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PMID:Pieiotropic effect of two cell wall mutants on the activity of some cell wall enzymes in the yeast Saccharomyces cerevisiae. 22 35

Saccharomyces cerevisiae cells contain a small internal pool of the secretory enzymes invertase and acid phosphatase. This pool increases up to 8-fold at 37 degrees C in a temperature-sensitive, secretion-defective mutant strain (sec 1-1). Cell division and incorporation of a sulfate permease activity stop abruptly at the restrictive temperature, while protein synthesis continues for several hours. Electron microscopy of mutant cells incubated at 37 degrees C reveals a large increase in the number of intracellular membrane-bound vesicles, which are shown by histochemical staining to contain the accumulated acid phosphatase. The vesicles are removed and the accumulated enzymes are secreted when cells are returned to a permissive temperature in the presence or absence of cycloheximide. These results are consistent with a vesicle intermediate in the yeast secretory pathway and suggest that exocytosis may contribute to cell-surface growth.
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PMID:Secretion and cell-surface growth are blocked in a temperature-sensitive mutant of Saccharomyces cerevisiae. 37 86

Bakers' yeast (Saccharomyces cerevisiae) was equilibrated with distilled water and then packed into standardized pellets by centrifugation. The fractional space (S value) that was accessible to passive permeation was probed with a variety of mono- and divalent salts, mono- and disaccharides, polyols, substrates and products of beta-fructofuranosidase (EC 3.2.1.26) and acid phosphatase (EC 3.1.3.2), and a cross-linked polymer of sucrose (Ficoll 400). A simple but very reproducible method was developed to measure pellet volume. At the limit of zero osmolality for bathing medium, the interstitial space was 0.223 ml/ml of pellet, and the aqueous volume of cell envelopes was 0.117 ml/ml of pellet. Thus the cell envelope for this yeast, under these conditions, was approximately 15% of the total cell volume. At a finite osmolality, the space in a yeast pellet that was accessible to salt was accounted for by the sum of initial interstitial space, the volume of the cell envelopes, and the volume of water abstracted from the cells by osmosis. Plots of S value versus osmolality were linear for uncharged probes and curvilinear for all salts. When Ficoll and potassium thiocyanate were presented to the yeast in admixture, the S values for the salt increased continuously over the range of osmolality studied. However, the S values for Ficoll 400 (which did not penetrate the cell wall) were lower by an amount equilivalent to the cell envelopes; they increased in parallel with the S curve for salt up to 1.15 osmol/kg and then plateaued. The results support the concept of incipient plasmolysis at 1.15 osmol/kg, and the separation of protoplasm from the cell wall is indicated with more concentrated solutions. Such cells were still viable if slowly diluted in distilled water, but they were injured by the shock of rapid dilution. However, shocking the cells did not release beta-fructofuranosidase into the medium. The complete accessibility of salts toward killed cells was demonstrated with yeast that had been pretreated with heat, organic solvents, or glutaraldehyde.
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PMID:Permeability of the cell envelope and osmotic behavior in Saccharomyces cerevisiae. 40 15

beta-Glucanases secreted into culture fluid by protoplasts or intact cells of the yeast Saccharomyces cerevisiae were investigated for the presence of covalently linked carbohydrates. Gel filtration of the enzymes on Biogel A-1.5m showed that endo-beta-1,3-glucanase is a polydisperse enzyme of high-molecular weight which elutes in about the same volume as external yeast invertase. Exo-beta-glucanase was eluted from the gel as a much lighter enzyme. Endo-beta-1,3-glucanase added to a mixture of extracellular mannoproteins was precipitated by concanavalin A to a similar extent to mannan, invertase and acid phosphatase. Under the same conditions exo-beta-glucanase did not interact with the lectin, but was partially precipitated from the solution in the absence of foreign mannan or mannan-proteins. The results show that endo-beta-1,3-glucanase of S. cerevisiae is a mannoprotein of a similar nature to external invertase and acid phosphatase. However, exo-beta-glucanase appears to be a glycoprotein which does not contain the highly branched mannan polymer in its molecule.
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PMID:Interaction of concanavalin A with external mannan-proteins of Saccharomyces cerevisiae. Glycoprotein nature of beta-glucanases. 79 52

The effect of 8-hydroxyquinoline, a rapid inhibitor of RNA synthesis, was followed on the activity of a number of enzymes in cultures of the fission yeast Schizosaccharomyces pombe. Two types of effect were found. In the first the activity continued to rise for a period and then remained constant. This occurred with alkaline phosphatase, basal and derepressed acid phosphatase, hexokinase, and derepressed sucrase and maltase at low cell density. It is consistent with control being exercised by an unstable mRNA or by an unstable stimulator of translocation. In the second the activity increased above the control values for several hours. This occurred with basal sucrase and maltase, and suggests a stable mRNA and an unstable inhibitor of translation. The extent of 'superproduction' of sucrase varied with cell density and with growth medium and this may be due to differences in the degree of translational inhibition. The possiblilty of a stable mRNA has interesting implications for the control of enzyme synthesis through the cell cycle.
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PMID:The effect of 8-hydroxyquinoline on enzyme synthesis in the fission yeast Schizosaccharomyces pombe. 81 99

The relationship between enzyme activity, cell geometry, and the ploidy levels has been investigated in Saccharomyces cerevisiae. Diploid cells have 1.57 times the volume of haploid cells under nonlimiting growth conditions (minimal medium). However, when diploid cells are grown under conditions of carbon limitation, they have the same volume as haploid cells. Thus, by altering the environmental conditions, cell size can be varied independently of the degree of ploidy. The results indicate that the basic biochemical parameters of the cell are primarily determined by cell geometry rather than ploidy level. RNA content, protein content, and ornithine transcarbamylase (carbamoylphosphate: L-ornithine carbamoyltransferase, EC 2.1.3.3), tryptophan synthetase [L-serine hydro-lyase (adding indole), EC 4.2.1.20], and invertase (alpha-D-glucoside glucohydrolase, Ec 3.2.1.20) activity are related to cell volume, whereas acid phosphatase (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.2) activity, a cell surface enzyme, is related to the surface area of the cells. Fitness is determined by the activity of certain cell surface enzymes, such as acid phosphatase, diploids would be expected to have a lower fitness than haploids because of the lower surface area/volume ratio. However, when fitness is determined by the activity of an internal enzyme, diploids would be expected to have the same fitness as haploids. Results from competition experiments between haploids and diploids are consistent with these predictions. The significance of these results to the evolution of diploidy as the predominant phase of the life cycle of higher plants and animals is discussed.
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PMID:The relationship between enzyme activity, cell geometry, and fitness in Saccharomyces cerevisiae. 109 69

The mechanism of inhibition by 2-deoxy-D-glucose of the synthesis of yeast wall polysaccharides and glycoproteins was investigated in Saccharomyces cerevisiae cells and protoplasts. The extent of the inhibition of mannan and glucan synthesis was found to be dependent on whether glucose or mannose was used as the carbon source in the medium. During growth on glucose, 2-deoxy-D-glucose inhibited more intensively mannan than glucan formation. Biosynthesis of wall glucan was strongly suppressed in mannose medium. Selective incorporation of 2-deoxy-D-glucose occurred into that polysaccharide, synthesis of which was more inhibited under given conditions. Suggestive evidence has been obtained that the decisive factor for the proportion of glucan and mannan in the walls is the direction of glucose 6-phosphate/mannose 6-phosphate interconversion dependent on the exogeneous hexose. No close correlation was found between the inhibition of mannan synthesis and the appearance of the mannan-protein enzymes invertase and acid phosphatase. Effect of 2-deoxy-D-glucose was therefore investigated on the parallel synthesis of protein, mannan and several extracellular and intracellular enzymes in protoplasts grown on glucose and mannose. The results obtained pointed out that the hindrance of the secretion of mannan-protein enzymes is of a complex nature and related more to the inhibition of synthesis of the protein moiety than to the inhibition of glycosylation. Synthesis of several enzymes was found to be a subject of a metabolic control by 2-deoxy-D-glucose or its metabolites.
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PMID:Mechanism of 2-deoxy-D-glucose inhibition of cell-wall polysaccharide and glycoprotein biosyntheses in Saccharomyces cerevisiae. 110 Mar 78


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