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)

We investigated the effects of pectin, a soluble dietary fiber, on functional and morphological parameters of the small intestine in rats. A control group and a pectin-fed group were given a fiber-free elemental liquid diet and an elemental liquid diet containing 2.5% (w/w) pectin, respectively, for 2 weeks. The ileal mucosal specific activities of maltase, sucrase and alkaline phosphatase increased significantly in the pectin-fed group. Maltose absorption of the ileum, studied in vitro by the method of everted sacs and disaccharide-dependent potential difference, increased significantly in the pectin-fed group. The length of the small intestine as well as the villus height and crypt depth of both the jejunum and the ileum were significantly greater in the pectin-fed group. The crypt cell production rate of the jejunum and the ileum was also significantly greater in the pectin-fed group. Plasma enteroglucagon, but not gastrin, increased significantly in the pectin-fed group. These data suggest that pectin feeding results in hyperplasia of the small-intestinal mucosa and a significant increase in the enzyme activities of the brush border membrane of the ileum.
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PMID:Effect of pectin, a soluble dietary fiber, on functional and morphological parameters of the small intestine in rats. 254 93

The activity of enzymes releasing glucose and reducing sugars from sucrose, maltose, starch and dextran was compared in the same pooled samples of plaque fluid (PF) from 24 h human dental plaque. Equimolar amounts of glucose and fructose were released from sucrose in 3 h incubations. Reducing activity was released from sucrose or starch at a similar rate. The rate of glucose release from the starch substrate was similar to that from maltose but lower than that from sucrose. Raffinose was hydrolysed, indicating beta-fructosidase activity in PF. The hydrolysis of maltose, trehalose and melezitose confirmed the presence of alpha-glucosidase activity. Maltose was metabolized partially to a maltosaccharide. No dextranase activity was detectable in PF, and the soluble polymeric carbohydrate in PF was partially degraded by fungal dextranase. Starch was degraded to dextrins, maltose and glucose.
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PMID:Hydrolysis of some carbohydrate substrates by enzymes of pooled human dental plaque fluid. 617 18

The hydrolysis of maltose and isomaltose and of sucrose and isomaltose at two different catalytic sites of sucrase-isomaltase has been demonstrated. Maltose and sucrose are competing for the same catalytic center. This competing can be described by alternative substrate kinetics. Steady-state kinetic parameters Km and k0 (maximal reaction velocity per mol enzyme) for linear alpha-1,4 and alpha-1,6 glucosyloligosaccharides has been determined. Using these parameters subsite affinities for the catalytic sites of sucrase and isomaltase were computed. The different numbers of subsites for sucrase (2 subsites) and isomaltase (4 subsites) indicate, that the binding patterns for maltooligosaccharides and isomaltooligosaccharides are different. That means that for sucrase unproductive enzyme-maltooligosaccharide complexes are definitely less probable than the productive one. As in human small intestinal glucoamylase-maltase in the isomaltase moiety four subsites can be evaluated with affinity values (Ai): A1 = 2.6 (+/- 0.91), A2 = 13.8 (+/- 0.70), A3 = 1.1 (+/- 0.13) and A4 = 1.5 (+/- 0.13) kJ/mol using isomaltooligosaccharides. The two subsites of sucrase are evaluated to be A1 = 4.9 (+/- 0.70) and A2 = 16.7 (+/- 0.51) kJ/mol using maltooligosaccharides. The four subsite model for isomaltase and glucoamylase-maltase is an indication that these two enzymes are mechanistically homologous in binding linear glucosyl-oligosaccharides.
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PMID:Human small intestinal sucrase-isomaltase: different binding patterns for malto- and isomaltooligosaccharides. 762 34

Intravenous immunoglobulin infusion induces acute renal failure via a mechanism of osmotic nephrosis. Most reported cases are related to the use of sucrose-based intravenous immunoglobulin. Maltose-based intravenous immunoglobulin is thought to be a safer alternative and have a lower risk of renal toxicity than sucrose-based preparations. Maltase, but not sucrase, is present in the brush border of proximal convoluted renal tubules, where the maltose is metabolised. We report a case of maltose-based intravenous immunoglobulin-induced acute renal failure in an elderly diabetic woman. In this case, the risk factors included advanced age, hypovolaemia, sepsis, diabetes mellitus, and the high infusion rate of the intravenous immunoglobulin. Maltase is readily inhibited by hyperglycaemia; therefore, poor glycaemic control may predispose patients to develop acute renal failure even with the better-tolerated maltose-based intravenous immunoglobulin.
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PMID:Acute renal failure related to intravenous immunoglobulin infusion in an elderly woman. 1568 16

Excision of developing potato (Solanum tuberosum L.) tubers from the mother plant, followed by storage at 10 degrees C, resulted in a rapid, substantial decrease in sucrose synthase activity and considerable increases in hexose content and acid invertase activity. A comparison of the response of three genotypes, known to accumulate different quantities of hexoses in storage, showed that both sucrose synthase activity and the extent to which activity declined following excision were similar in all cases. However, there was significant genotypic variation in the extent to which acid invertase activity developed, with tubers accumulating the highest hexose content also developing the highest extractable activity of invertase. Similar effects were found in nondetached tubers when growing plants were maintained in total darkness for a prolonged period. Furthermore, supplying sucrose to detached tubers through the cut stolon surface prevented the decline in sucrose synthase activity. Maltose proved to be ineffective. Western blots using antibodies raised against maize sucrose synthase showed that the decline in sucrose synthase activity was associated with the loss of protein rather than the effect of endogenous inhibitors. Although there were indications that maintaining a flux of sucrose into isolated tubers could prevent the increase in acid invertase activity, the results were not conclusive.
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PMID:Sucrose Metabolism in Tubers of Potato (Solanum tuberosum L.): Effects of Sink Removal and Sucrose Flux on Sucrose-Degrading Enzymes. 1666 26