Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The postition of a number of human intestine brush border membrane enzyme activities in polyacrylamide gels after electrophoresis has been determined. These activities are, in order from the origin, maltase/glucoamylase, lactase/phlorizin hydrolase, maltase/sucrase/isomaltase, enteropeptidase, trehalase and gamma-glutamyl-transferase. Leucylnaphthylamide hydrolyzing activity was inactivated by sodium dodecylsulfate and its position was not determined. The positions of the activities have been correlated with the positions of protein bands previously determined. One such band situated between enteropeptidase and alkaline phosphatase has not been identified.
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PMID:Enzymes of the human intestinal brush border membrane. Identification after gel electrophoretic separation. 23 25

The influence of bile salts on the mucosal surface of rat jejunum was tested with an in vivo technique of segmental perfusion. Sodium taurocholate and chenodesoxycholate were applied in a concentration of 3 mmol/l. The release of 5 brush border membrane enzymes, 5 cytosolic, 1 mitochondrial, and 2 lysosomal enzymes during a perfusion time of 150 min as well as morphological alterations after bile salt treatment were investigated. Among the membrane enzymes, due to their superficial localization, the solubilization of enteropeptidase and alpha-1,4-glucosidase was highest both in the control perfusion and in the presence of bile salts. At the same time, cytoplasmic enzyme activities were liberated extensively whereas lysosomal and mitochondrial enzymes were scarcely detectable. This disproves any serious injury of the enterocytes. Electronmicroscopic results supported this suggestion. After administration of taurocholate (in physiological concentration), only an occasional diminution of the glycocalyx was observed and even chenodeoxycholate (in an unphysiological concentration) caused only negligible destructions of intestinal brush borders. Investigations with ruthenium red to contrast the glycocalyx showed a partially unchanged structure. Microvesiculation from the microvilli was observed in many electron microscopic photographs. That is a possibility for the release of membrane-bound and cytosolic enzymes without destruction of enterocytes.
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PMID:[Biochemical and morphologic studies on the effect of bile acids on the epithelium of the rat jejunum]. 643 37

The technique of segmental perfusion was applied in vivo to study the release of enzymes from the mucosa cells under the influence of bile salts. Five brush border membrane enzymes, five cytosolic, one mitochondrial and two lysosomal enzymes were measured. Spontaneous release (Ringer solution), due to their superficial localization, was greatest for enteropeptidase and alpha-glucosidase. 3 and 10 mmol/l sodium taurocholate, and 0.5 and 3.0 mmol/l chenodeoxycholate were used. Surprisingly, the majority of cytosolic enzymes was released to a greater extent than membrane enzymes. On the other hand, lysosomal or mitochondrial enzymes were low or absent in the perfusion medium, a finding that excludes a serious injury to the mucosa cells. It must be inferred, therefore, that cytosolic enzymes are regularly externalized during the digestive process, the glycocalyx perhaps being a common matrix for pancreatic, membrane-associated and cytosolic enzymes.
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PMID:Release of enzymes from rat jejunal mucosa by bile salts. 685 14

To investigate dietary protein level effects on digestive mechanisms, weaned piglets were fed for 45 d with diets containing 20%, 17%, or 14% crude protein (CP) supplemented to meet requirements for essential amino acids. This article describes the influence of dietary protein on gastrointestinal hormones and expression of an array of digestive enzymes in the gastrointestinal tract and pancreas. Results indicated that there were no significant differences in expression of enzymes involved in carbohydrate digestion, except for maltase in the duodenum. In the jejunum, amylase expression in pigs fed 20% CP was much higher than that in pigs fed other diets (P<0.05) and maltase expression in those fed 17% CP was higher than that in other treatments (P<0.05). Although there were no remarkable differences in expression of aminopeptidase in the small intestine or carboxypeptidase in the pancreas (P>0.05), there was a trend towards higher expression of various proteases in pigs fed 17% CP. The duodenal expression of enteropeptidase in diets with 14% and 17% CP was significantly higher than that with 20% CP (P<0.05), but treatment differences did not existed in jejunum (P>0.05). The expression of GPR93 as a nutrient-responsive G protein-coupled receptor in 14% and 17% CP diets was significantly higher than that in 20% CP diet in the small intestine (P<0.05). The expressions of genes for pancreatic enzymes, lipase and elastase, were significantly higher in pigs fed diets with low CP, while similar trends occurred for carboxypeptidase, chymotrypsin and amylase. Conversely, the gastric expressions of pepsinogen A and progastricsin were lower with the 17% CP diet. Differences between treatments were found in the gastric antral contents of cholecystokinin and somatostatin: both increased in pigs fed 17% CP, accompanied by decreased content of motilin, which was also seen in plasma concentrations. These patterns were not reflected in duodenal contents. In general, 17% dietary CP was beneficial to the digestion of nutrient substance in the gastrointestinal tract.
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PMID:Influence of low protein diets on gene expression of digestive enzymes and hormone secretion in the gastrointestinal tract of young weaned piglets. 2770 44