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:3.2.1.20 (alpha-glucosidase)
4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dietary fibres (Plantago ovata seeds, P. ovata husks, wheat bran, alfalfa, pectin, xylan) were incubated in vitro with gastrointestinal enzymes (pepsin, trypsin, chymotrypsin, lipase, alpha-amylase, maltase, lactase) in buffer solutions at concentrations of 1-5% for 10-30 min at 37 degrees C. All fibres induced sometimes pronounced changes in enzyme activity, but the effect of the different fibres on the various enzymes varied individually and was not predictable. Both P. ovata preparations had no (pepsin, trypsin, alpha-amylase) or only stimulating (chymotrypsin, lipase, lactase) actions whereas all other fibres showed inhibiting as well as stimulating influences. Wheat bran induced the most pronounced alterations increasing lipase, maltase and lactase activity and inhibiting alpha-amylase activity. Pectin and xylan were comparable in decreasing lipase and pepsin activity and in increasing chymotrypsin activity but had opposite effects on maltase activity. Alfalfa was able to stimulate lactase and lipase activity but depressed trypsin and alpha-amylase activity. The inactivation of enzymes by dietary fibres can, at least partly, be explained by adsorption to the fibre or by the presence of enzyme inhibitors especially in natural compounds. The reasons for activation processes are unknown. As enzyme activities are decisive for food digestion, the properties of the individual fibres should be carefully considered when used as dietary supplement in physiological or pathological conditions.
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PMID:Interference of dietary fibres with gastrointestinal enzymes in vitro. 248 92

The endoplasmic reticulum-localized enzyme alpha-glucosidase II is responsible for removing the two alpha-1,3-linked glucose residues from N-linked oligosaccharides of glycoproteins. This activity is missing in the modA mutant strain, M31, of Dictyostelium discoideum. Results from both radiolabeled pulse-chase and subcellular fractionation experiments indicate that this deficiency did not prevent intracellular transport and proteolytic processing of the lysosomal enzymes, alpha-mannosidase and beta-glucosidase. However, the rate at which the glucosylated precursors left the rough endoplasmic reticulum was several-fold slower than the rate at which the wild-type precursors left this compartment. Retention of glucose residues did not disrupt the binding of the precursor forms of the enzymes with intracellular membranes, indicating that the delay in movement of proteins from the ER did not result from lack of association with membranes. However, the mutant alpha-mannosidase precursor contained more trypsin-sensitive sites than did the wild-type precursor, suggesting that improper folding of precursor molecules might account for the slow rate of transport to the Golgi complex. Percoll density gradient fractionation of extracts prepared from M31 cells indicated that the proteolytically processed mature forms of alpha-mannosidase and beta-glucosidase were localized to lysosomes. Finally, the mutation in M31 may have other, more dramatic, effects on the lysosomal system since two enzymes, N-acetylglucosaminidase and acid phosphatase, were secreted much less efficiently from lysosomal compartments by the mutant strain.
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PMID:Biogenesis of lysosomal enzymes in the alpha-glucosidase II-deficient modA mutant of Dictyostelium discoideum: retention of alpha-1,3-linked glucose on N-linked oligosaccharides delays intracellular transport but does not alter sorting of alpha-mannosidase or beta-glucosidase. 250 71

Urinary excretion of alpha-glucosidase (AGL), gamma-glutamyltransferase (GGT) and ribonuclease (RNase), and serum amylase and immunoreactive trypsin (IRT) were determined in 38 control subjects, 48 patients with pancreatic cancer, 77 with chronic pancreatitis and 47 with extrapancreatic diseases in order to ascertain the presence of a renal tubular damage and to investigate its etiology. A significantly increased frequency of pathological results for all urinary enzymes was documented in the various groups of patients as compared to controls. Significant correlations were detected among AGL, GGT and RNase. Considering the subjects as a whole, GGT and RNase excretions correlated with serum IRT and amylase; the two urinary enzymes were found to be higher when jaundice was present. In chronic pancreatic disease enzymuria was related to increased serum pancreatic enzymes; in extrapancreatic diseases it was associated to hyperbilirubinemia. The vast majority of patients with pancreatic cancer and elevated urinary enzymes presented hepatic metastases and/or jaundice. We can conclude that an anatomical and functional tubular impairment is detectable in some patients with chronic pancreatic and extrapancreatic diseases. Tubular damage seems to least in part to be related to pancreatic inflammation and necrosis in chronic pancreatic disease, while jaundice may be found to play an important role in diseases of the hepatobiliary tract. In pancreatic cancer, liver dysfunction (presence of liver metastases and/or extrahepatic cholestasis) also appears to be involved in altering tubular cells.
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PMID:Renal tubular dysfunction in pancreatic cancer and chronic pancreatitis. 256 74

The first steps of the biosynthetic pathway of high molecular weight polylactosamine-type glycopeptides from rat Zajdela hepatoma cells were studied by pulse-chase experiments, biochemical analysis and by inhibition of N-glycosylation. It is clear that this process involves firstly the transfer of a lipid-linked high-mannose oligosaccharide precursor to a protein moiety in a similar way to that of N-linked glycopeptides of a more common size range according to the classical 'cycle of dolichol'. In the presence of enzymes which are inhibitors of the processing of high-mannose oligosaccharide chains, this class of oligosaccharides was considerably increased, whereas polylactosamine chains and lower complex N-linked glycopeptides were concomitantly decreased in the same kinetics and the same ratio. As expected in the presence of N-methyldeoxynojirimycin, which is an alpha-glucosidase inhibitor, high-mannose oligosaccharides remained glycosylated and are mostly of the Glc1-3Man9GlcNAc type. In the presence of swainsonine, which is an alpha-mannosidase (EC 3.2.1.24) inhibitor, these chains were devoid of glucose residues. In addition, some chains displayed hybrid structures. It appears, therefore, that the first steps of the biosynthesis of polylactosamine-type and N-linked oligosaccharides of a more common size range proceed similarly and that differences between their biosynthetic pathways occur during the elongation phase, which leads to their final respective structures. Glycopeptides prepared from the cell surface by mild trypsin treatment as well as from entire cells, previously treated or not by processing inhibitors, display the same gel filtration patterns indicating that modifications in protein glycosylation do not prevent glycoprotein insertion into the cell membrane.
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PMID:Biosynthesis of high molecular weight polylactosamine-type glycopeptides in rat Zajdela hepatoma ascites cells. 271 99

Since they are found to be increased in lesions of acute necrotic ulcerative gingivitis or marginal periodontitis, agents for these diseases. In the present study, 38 pure cultured strains were obtained as a result of isolation and culture of samples collected from lesions of marginal periodontitis (periodontal pokets), and the biological and biochemical characteristics of these strains were investigated. 1) Light microscopy (including dark-field microscopy) and transmission electron microscopy (negative staining) were used for observation of the morphology and cellular structure of the strains. The cells had a spiral shape, and showed active movement. Based on the above findings the cultured strains were all confirmed to be spirochetes of small to medium size, being 0.08-0.24 micron in width. 2) Growth and motility of the strains were investigated on various types of culture medium. Intense growth and movement were noted in strains cultured in bovine liver exudate medium containing horse serum (pH 7.2) at 37 degrees C under anaerobic conditions produced by the evacuation-replacement method (95% N2, 5% CO2) for 3-7 days after inoculation. 3) Thirty-five strains were positive for indole production and decomposition of urea, mucin, hippuric acid and esculin. Production of hydrogen sulfied was observed in 31 strains. In decomposition tests for 17 carbohydrates, 17 strains were positive for galactose and 14 strains were positive for glucose, while 11 strains were positive for dextrin and 10 strains for fructose upon decomposition of soluble starch. Other carbohydrates were also decomposed by a few strains. 4) In an investigation of the production of alcohol and lower fatty acids, among the metabolic products detected by gas chromatography, a large amount of acetic acid and small amounts of ethanol, lactic acid, propionic acid, pyruvic acid were observed. 5) The results of enzyme activity tests using an API ZYM system indicated relatively high activities of esterase, esterase-lipase, alpha-glucosidase, alkaline phosphatase, trypsin and acid phosphatase.
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PMID:[Biological and biochemical characteristics of the oral spirochetes isolated from the focus of marginal periodontitis]. 276 48

In order to investigate the role of circulating free trypsinogen and renal tubular dysfunction in affecting trypsin plasma-urine transfer, serum immunoreactive trypsin (IRT), its urinary output, IRT molecular size distribution, filtrable immunoreactive trypsin, gamma-glutamyltransferase and alpha-glucosidase outputs were studied in 6 control subjects, 9 patients with pancreatic cancer and 15 with chronic pancreatitis. The majority of immunoreactivity was always eluted at a molecular weight of about 24,000 and might therefore be considered as free trypsinogen. Variable amounts of IRT at higher molecular weights, possibly represented by trypsin-inhibitor complexes, were also detected. Increasing IRT levels were generally accounted for by free trypsinogen, regardless of the nature of the disease. Unlike serum free trypsinogen levels, renal tubular damage, evaluated by means of the excretion of two high-molecular weight urinary enzymes, seems to play a prominent role in explaining trypsin plasma-urine transfer.
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PMID:Molecular size distribution of immunoreactive trypsin and renal tubular dysfunction: role in trypsin plasma-urine transfer. 288 33

Full-value diets of similar composition were given to male rats weighing 207-230 g, by intravenous (group 1) or intragastric (group 2) routes. The proportion of amino acids, fats and carbohydrates was 9.9:15.7:74.4 (with regard to their calorific value). The diet calorific value comprised 60.6 kcal/rat/day. An average mass increase in group 1 was 2.44 +/- 0.14 g/day, in group 2 - 1.75 +/- 0.11 g/day. The protein content and activities of alpha- and gamma-amylase, invertase, maltase, and glycil-L-leucine dipeptidase were assayed in the intestinal mucosa of the proximal portion of the small intestine in group 1 rats, while a decreased alpha-amylase activity in the distal portion of the small intestine was recorded in the animals of group 2. The mass of the pancreas in the rats of group 1 and 2 was authentically lower than in the control rats which received oral feeding with natural foods. The lowest mass of the pancreas was observed in the rats of group 1. Specific activity of trypsin, lipase and RNase in the pancreatic tissues of rats in groups 1 and 2 was similar. The results of the study have evidenced a lowered function of the digestive system under conditions of artificial feeding, especially in case of intravenous nutrition.
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PMID:[Digestive function of the small intestine and pancreas in rats on artificial feeding]. 309 Jul 82

The development of the human fetal gastrointestinal tract takes place early during gestation. The pancreas although developed by morphological means at the 16th week of gestation excretes its exocrine enzymes later at the 24th week of gestation except for amylase which reaches its full activity 6 months after birth. Trypsinogen secreted at the 24th week is activated into trypsin by enterokinase at the 26th week of gestation whereas lipase and colipase are secreted from the 24th week. The small intestine starts developing at the 10th week morphologically and functionally. At the same time when villi and crypts start to develop at the 11th to 12th week the first enzyme activities can be detected, i.e. sucrase-isomaltase, maltase-glucoamylase and lactase. Also peptidases and lysosomal hydrolases are measured at this age. With the exception of lactase, intestinal enzymes reach sufficient activities at the 25th week of gestation. Lactase activity remains low until the 32nd-34th week. For the digestion and absorption of lipids, protein and carbohydrates the gastrointestinal tract of premature infants under 1500 g in rather well equipped. Lipids are hydrolysed by the mutual action of breast milk lipase, lingual lipase, gastric lipase and pancreatic lipase. The carbohydrates lactose and oligosaccharides as supplements to breast milk are hydrolysed by lactase, sucrase-isomaltase and maltase-glucoamylase. Breast milk proteins and cows milk hydrolysates are digested by pancreatic proteases into oligopeptides which can be hydrolysed within the lumen by brush border peptidases and be absorbed. Peptides also can actively be transported through the microvillus membrane and be hydrolyzed by intracellular peptidases.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Nutrition of premature infants below 1,500 g: enteral prerequisites]. 309 34

Intestinal and pancreatic enzyme activities are known to respond to changes in dietary composition. Studies in rats and humans suggest that adaptive mechanisms differ between species in response to altered intakes of carbohydrate and fat. Because of increased use of the pig in the study of human nutrition, we compared the responses of pancreatic enzymes and intestinal disaccharidases in groups of 7- to 10-week-old pigs fed either high-carbohydrate/low-fat (70 cal% starch, 25% protein, 5% fat) or low-carbohydrate/high-fat (5, 25, 70%, respectively) diets for 7 and 30 days. No changes were observed in the activities for lactase, trypsin, or chymotrypsin or in the tissue protein concentrations, regardless of diet duration. High-carbohydrate/low-fat intake resulted in higher specific activities of sucrase, maltase, and amylase for both periods studied. Low-carbohydrate/high-fat intake resulted in higher specific activities of pancreatic lipase for both periods studied. The response of the intestinal disaccharidases differs from that observed previously in rodents but resembles the response reported in humans. Conversely, amylase and lipase responded similarly to the pattern in the rat. These data support the continued use of the pig as a suitable model in the study of adaptation to altered intakes of carbohydrate and fat.
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PMID:Effect of diet on intestinal and pancreatic enzyme activities in the pig. 319 78

The enzymatic activities of 53 strains of Pseudomonas cepacia were determined by using the API ZYM system. Strong alkaline phosphatase, acid phosphatase, butyrate esterase, caprylate esterase, myristate lipase, leucine arylamidase, and phosphoamidase activities were consistently detected in all strains. Weak activities were observed for valine arylamidase, beta-glucosidase, and N-acetyl-beta-glucosaminidase. No activities could be demonstrated for cystine arylamidase, trypsin, chymotrypsin, alpha-galactosidase, beta-galactosidase, beta-glucuronidase, alpha-glucosidase, alpha-mannosidase, and alpha-fucosidase. Enzymatic activities of pseudomonads may provide useful information about their pathogenesis and information for identification of Pseudomonas species.
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PMID:Enzymatic characterization of Pseudomonas cepacia by API ZYM profile. 335 98


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