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:3.2.1.26 (invertase)
4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Branched cyclodextrins (CDs) have been formed by the thermal transfer of a fructosyl group from sucrose to O-6 of one of the glucose residues of cyclomaltohexa- and hepta-ose (alpha-CD and beta-CD). In each case the fructosyl group adds almost entirely in the beta configuration. The resultant fructosylcyclodextrins (Fru-CDs) show increased solubility in water and, in the case of Fru-beta-CD increased ability to solubilize sparingly soluble compounds by inclusion, relative to the parent cyclodextrins. However, the Fru-CDs have similar abilities to form complexes as their respective parent CDs. Fru-CDs act as inhibitors of invertase.
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PMID:Stereoselective thermal transfer of fructose from sucrose to cyclodextrins. 773 69

The invertase activity of intact Saccharomyces cerevisiae submitted to freezing-thawing was affected by pH, the chemical nature of the buffer, and the freezing cooling rate (CR), leading in some cases to a complete invertase inactivation (acetate buffer, pH 4.0, CR = 0.5 degree C/min). Once established under adequate freezing conditions the invertase activity remained unchanged after freeze-drying. Nevertheless, in some cases the cell-growing capability after freeze-drying diminished around 70%, mainly if the frozen cell suspension was attained through freezing carried out at CR = 0.5 degree C/min. Water sorption isotherms of freeze-dried samples (freeze-dryer Edwards L-4KR; 30 degrees C and 0.1 mB) were determined at 10 and 25 degrees C. The monolayer moisture content (MMC) at each temperature (12.7 and 3.71 for 10 and 25 degrees C, respectively) was calculated from isotherms by applying BET and GAB models. Freeze-dried yeast with water activity (Aw) between 0 and 0.33 (about the MMC value) maintained at 25 degrees C for 235 days and at 89 degrees C for 15 min retained at least 85% of its original invertase activity (IA), whereas samples with Aw > MMC lost at least 60% of its IA. X ray diffraction showed that the freeze-dried cake before and after storage presented an amorphous structure.
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PMID:Effect of moisture content on the invertase activity of freeze-dried S. cerevisiae. 792 95

The aim of the present work was to study whether zinc chloride added to the drinking water of rabbits affected the intestinal absorption of D-galactose and the activity of sucrase in the jejunum. The results showed that zinc decreased D-galactose absorption in the jejunal tissue. The effect appeared to be due mainly to an action on the active transport of the sugar by the mucosal border of the intestinal epithelium, because the zinc seemed not to affect its diffusion across the intestinal epithelium. Zinc was also shown to inhibit the (Na(+)-Ka+)-ATPase activity of the enterocyte, which might explain the inhibition of the Na(+)-dependent transport of D-galactose. Nevertheless, a possible direct action of the zinc ion on the Na(+)-dependent carrier cannot be discounted. Zinc did not alter the activity of sucrase in the jejunum of the rabbit.
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PMID:Action of zinc on enzymatic digestion and intestinal transport of sugar in the rabbit. 797 88

Conidia of certain penicillin producing Penicillium chrysogenum industrial strains produced polyfructose. Two types of polyfructoses were formed by conidia of P. chrysogenum B10 from sucrose and with less yield from raffinose. Ten percent of fructans were in water insoluble form attached to the outer wall of conidia. The other, ethanol precipitable fructan formed a colloid opalescent solution. The latter had inulin type beta (2-->1) bonds--identified by 13C NMR spectroscopy--between fructose molecules and had a molecular weight of 217,000 Daltons. The KM value of sucrose hydrolysis--the first step of inulin production--was 0.86 M. The invertase hydrolysed about 70% of sucrose on the second day. Optimal conditions for inulin formation were: pH 6.0, 25-45 degrees C, 100 mg/ml sucrose, 10(7) spore/ml. The maximum conversion rate of fructose from sucrose into precipitable inulin was about 10% after 48 h incubation. The inulin production could be inhibited by glucose.
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PMID:Inulin formation of penicillin producing industrial Penicillium chrysogenum strains. 797 14

Important variations in intestinal biochemical characteristics were recorded after ingestion of a single dose of spermine (8 mumol 50 microliters-1 water) by rats which were 11 days old. Two phases of events were observed. During the first hours which follow spermine administration, we mainly noted: -a decrease in the weight of DNA and of intestine per cm, -a decrease in the specific activity of lactase and of maltase, -an increase in the spermine content. The second phase of events started about 30 h after spermine ingestion. We observed: 1. An increase in the weight of DNA and of intestine per cm; 2. The appearance of sucrase activity; 3. An increase in maltase specific activity; 4. An increase in spermidine content; 5. tendency to normalization of the spermine content. The epithelial cells of the proximal intestine were isolated in fractions from the top of the villi to the bottom of the crypts. Two hours after spermine administration, we noted: 1. An increase in the lactase specific activity of the epithelial cells located at the top of the vili; 2. A decrease in the activity of the cells situated at the lower part of the crypts; 3. An increase in the specific activity of maltase contained in the different categories of enterocytes, except in those from the bottom of the crypts; 4. An increase in the content of putrescine present in the epithelial cells of the whole axis excepted in the bottom of the crypts; 5. An increase in the spermidine and spermine content of all the cell fractions.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Evolution of biochemical parameters characterizing the proximal small intestine after orally administered spermine in unweaned rats. 806 97

Micro-organisms have developed systems to adapt to sudden changes in the environment. Here we describe the response of the yeast Saccharomyces cerevisiae to osmotic stress. A drop in the water activity (aw) of the medium following the addition of NaCl led to an immediate shrinkage of the cells. During the 2 h following the osmotic shock the cells partially restored their cell volume. This process depended on active protein synthesis. During the recovery period the cells accumulated glycerol intracellularly as a compatible solute and very little glycerol was leaking out of the cell. We have investigated in more detail the enzymes of glycerol metabolism and found that only the cytoplasmic glycerol-3-phosphate dehydrogenase was strongly induced. The level of induction was dependent on the yeast strain used and the degree of osmotic stress. The synthesis of cytoplasmic glycerol-3-phosphate dehydrogenase is also regulated by glucose repression. Using mutants defective in glucose repression (hxk2 delta), or derepression (snf1 delta), and with invertase as a marker enzyme, we show that glucose repression and the osmotic-stress response system regulate glycerol-3-phosphate dehydrogenase synthesis independently. We infer that specific control mechanisms sense the osmotic situation of the cell and induce responses such as the production and retention of glycerol.
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PMID:Characterization of the osmotic-stress response in Saccharomyces cerevisiae: osmotic stress and glucose repression regulate glycerol-3-phosphate dehydrogenase independently. 808 59

The TESS line, the first tester line of the Suncus has been developed. The TESS shrews are homozygous for three morphological mutant genes, ch, cr and rd. The gene (suc) for sucrase activity deficiency in intestinal brush-border membranes also exists in the line, and its frequency was 34.3%. The deficients could easily be identified by the drastic body-weight losing up to more than 15% of the initial weight, that aroused two days after replacement of the drinking water for its 10%-sucrose solution. The TESS shrews have been maintained as a closed-colony consisting of more than 30 individuals, and will be utilized in linkage analysis with the four loci (ch, cr, rd and suc).
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PMID:TESS line: a laboratory line of the musk shrew (Suncus murinus, Insectivora), triple-homozygous for the curly hair (ch), cream coat-color (cr) and red-eyed dilution (rd) genes and segregating the sucrase deficients (suc/suc). 811 32

Balance studies utilizing laying hens and adult cockerels were conducted to determine the influence of oligosaccharides (raffinose and stachyose) present in canola meal (CM) on the digestibility of nonstarch polysaccharides (NSP) and on the TMEn of the meal. Ethanol extraction was used to produce oligosaccharide-free meal, and exogenous dietary enzymes (alpha-galactosidase and invertase) were employed to bring about oligosaccharide hydrolysis in the intestinal tract of the birds. In each of two balance trials, six hens individually housed were randomly allotted to each of the experimental diets in completely randomized design. Experiment 1 consisted of a factorial arrangement of treatments (two sources of proteins with or without enzyme supplementation), whereas Experiment 2 consisted of five diets: semipurified CM control, semipurified ethanol-extracted CM; semipurified ethanol-extracted CM plus raffinose; conventional CM; and conventional ethanol-extracted CM. Elimination of oligosaccharides by the use of exogenous dietary enzymes had no effect on NSP digestion. Removal of oligosaccharides by ethanol extraction increased NSP digestibility from 4 to 8%. A more pronounced effect (17% NSP digestion) was noted in hens fed a wheat-based diet containing 30% oligosaccharide-free CM. This latter effect may have been due to the relatively high content of water-soluble polysaccharides contributed by the wheat portion of the diet. The TMEn content of ethanol-extracted CM was 2,302 kcal/kg as compared with 2,426 kcal/kg for untreated CM. The data indicate no advantage of oligosaccharide removal with regard to the nutritive worth of canola meal.
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PMID:Oligosaccharides in canola meal and their effect on nonstarch polysaccharide digestibility and true metabolizable energy in poultry. 816 61

We investigated the effect of polydextrose, one of the water-soluble non-digestible polysaccharides, on the activities of brush-border membrane enzymes of small intestine in rats and on glucose absorption with relation to the thickness of the unstirred water layer in humans. Rats were fed a 5% polydextrose-supplemented elemental diet for 2 or 4 wk. The mucosal alkaline phosphatase, maltase, and sucrase activities were measured in the upper, middle, and lower intestine. There was no significant difference between control and polydextrose groups. The potentiometric tube was inserted orally in the jejunum. Glucose absorption was measured by perfusion with the solutions with or without 5% polydextrose. There was no significant difference in the glucose absorption rate or the thickness of the unstirred water layer between control and polydextrose solutions. The increase in viscosity of the polydextrose solution was negligible. This study indicated that polydextrose had no effect on the thickness of the unstirred water layer and did not inhibit glucose absorption in humans.
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PMID:Polydextrose and activities of brush-border membrane enzymes of small intestine in rats and glucose absorption in humans. 835 63

To assess the effects of hypothyroidism (HT) on small-intestinal function, HT was induced in rats (120-150 g) by methimazole in drinking water. After 6 wk of methimazole, intestinal absorption studies were performed in HT and in control (C) rats by in situ luminal perfusion of a 20-cm proximal jejunal loop with a bicarbonate buffer containing sodium, glucose or fructose, glycine or lysine, and phenol red as a nonabsorbable marker for determination of water fluxes. Mucosa from the perfused segment was taken for assay of disaccharidases and ATPases and for light and electron microscopy. Compared with C rats, HT rats had significantly lower jejunal transport rates of water (2.54 +/- 0.36 versus 5.02 +/- 0.7 microL/min/microgram mucosal protein, p < 0.03), sodium (37.1 +/- 10.3 versus 102.7 +/- 18.6 mumol/min/microgram protein, p < 0.05), and glucose (1.49 +/- 0.28 versus 5.17 +/- 0.82 mumol/min/microgram protein, p < 0.02). A reduction in glycine transport was also observed but did not attain statistical significance (p = 0.058). Fructose and lysine transport was unchanged. Mucosal sucrase and lactase activities were similar in both groups, but Na,K-ATPase was significantly lower in HT rats (1.17 +/- 0.3 versus 4.03 +/- 1.5 mumol inorganic phosphate/h/mg protein; p < 0.05), with a diminution of ouabain binding sites by 41.5%. Light microscopy of jejunal mucosa from HT rats did not differ from that from C rats; electron microscopy showed mild mitochondrial swelling in HT enterocytes. A group of HT rats were treated with L-thyroxine during 4 wk; these rats had absorption rates, mucosal enzyme activities, ouabain binding, and mucosal morphology not different from C rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of hypothyroidism on jejunal mucosal function: study by in situ luminal perfusion in rats. 839 45


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