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)

We evaluated the Harleco alpha-glucosidase/hexokinase/glucose-6-phosphate dehydrogenase-coupled alpha-amylase method, bu use of the GEMSAEC centrifugal analyzer. Performance evaluation included kinetic studies of substrate and maltose hydrolysis as well as effects of endogenous glucose and fructose. The reagent was found to give a linear response with alpha-amylase activity to greater than 1200 U/liter. Within-run precision resulted in coefficients of variation (CV) of 0.9 to 3.2% over the range studied. Day-to-day precision corresponded to CV's of 2.4 to 4.4% over the same range of alpha-amylase procedure was found to be good (r = 0.997) for patients' sera examined.
Clin Chem 1978 Sep
PMID:Enzyme-coupled ultraviolet determination of alpha-amylase activity with the GEMSAEC centrifugal analyzer. 35 41

In rats fed for 4, 15, and 30 days with increased amount of proteins, lipids, and carbohydrates, considerable shifts occurred in activity of enzymes of the pancreas (amylase, protease, and lipase) and small intestine (gamma--amylase, maltase group, invertase, peptidhydrolase, monoglyceriflipase). Mathematical analysis suggested a close connection between the adaptive shifts in the enzyme systems maintaining the lumen and the membrane types of digestion. The protein diet augments the proteolytic enzyme chain the lipid diet--the lipolytic chain, and the carbohydrate diet--the carbohydrate chain. The shifts should be regarded as an integrative adaptive response of the enzyme spectrum of the pancreas and small intestine to alterations in the food composition.
Fiziol Zh SSSR Im I M Sechenova 1978 Sep
PMID:[Interrelationships between the enzymatic functions of the pancreas and small intestine during adaptive processes]. 36 44

We used a double labeling technique to search for molecular defects in two fibroblast strains obtained from patients with Pompe's disease. Analysis of the double labeled subcellular fractions by sodium dodecyl sulfate (SDS) electrophoresis did not reveal any abnormalities except in the "mitochondrial-lysosomal" fraction. In this fraction ratio deviations indicated that in Pompe's disease there was a significant decrease in counts of a protein with molecular weight of about 29,000. After solubilization by freeze-thawing this protein was shown to have an isoelectric point of 7.9 in contrast to the alpha-glucosidase which focused at about pH 4.7. Two-stage gel studies demonstrated an estimated 90% reduction of this protein in Pompe's disease. Two-stage studies of acid alpha-glucosidase did not show any abnormal ratios of leucine incorporation. Similar although quantitatively less pronounced results were obtained in the study of skin fibroblasts from a patient with adult glycogen storage disease type II.
Pediatr Res 1978 Sep
PMID:Searching for molecular abnormalities in genetic diseases by the use of a double labeling technique. II. Deficiency of a basic protein in fibroblasts of patients with Pompe's disease. 36 58

Hydrogenated palatinose, an equimolar mixture of alpha-D-glucopyranosido-1,6-sorbitol and alpha-D-glucopyranosido-1,6-mannitol, was investigated as a potential oral sugar substitute in the following experiments in man and rat. 1. Enzymatic cleavage occurred at slow rates by maltase (alpha-glucosidase) of jejunal mucosa, liver lysosomes and yeast. 2. Part of ingested hydrogenated palatinose arrived unsplit at the caecum of the rat and underwent fermentation there; excretion in feces and urine are neglegible in man and rat. 3. Growth and maintenance of rats demonstrated 20--40 percent diminished caloric utilisation of diets containing 34.5 percent hydrogenated palatinose whereas indirect calorimetry in man showed about 50 percent caloric deficit. 4. Blood sugar did not increase in man after oral doses up to 100 g. 5. The capacity of the rat kidneys for excretion of hydrogenated palatinose and its constituents was high, symptoms of incompatibility were not observed.
Res Exp Med (Berl) 1978 Sep 25
PMID:Metabolism of hydrogenated palatinose, an equimolar mixture of alpha-D-glucopyranosido-1,6-sorbitol and alpha-D-glucopyranosido-1,6-mannitol. 36 72

We have studied somatic cell hybrids between thymidine kinase (EC 2.7.1.75) deficient mouse cells and human diploid fibroblasts for the expression of human acid alpha-glucosidase (EC 3.2.1.20). A deficiency in this enzyme is associated with the type II glycogenosis or Pompe disease. All 30 somatic cell hybrids selected in hypoxanthine/aminopterin/thymidine medium expressed human acid alpha-glucosidase and galactokinase (EC 2.7.1.6) and retained human chromosome 17; counterselection of the same hybrids in medium containing 5-bromodeoxyuridine resulted in the growth of hybrids that concordantly lost the expression of human acid alpha-glucosidase and galactokinase as well as human chromosome 17. Hybrids between thymidine kinase-deficient mouse cells and fibroblasts from a patient with Pompe disease that contained human chromosome 17 were found not to express human acid alpha-glucosidase. Because we have already shown that hybrids between mouse peritoneal macrophages and GM54VA simian virus 40-transformed human cells selectively retain human chromosome 17 and lose all other human chromosomes, we tested 13 independent mouse macrophage x GM54VA hybrid clones, including two that retained human chromosome 17 and no other human chromosomes, for the expression of human acid alpha-glucosidase and galactokinase. All 13 hybrid clones were found to express these human enzymes. Thus, we conclude that the gene coding for human acid alpha-glucosidase is located on human chromosome 17.
Proc Natl Acad Sci U S A 1979 Sep
PMID:Genetics of type II glycogenosis: assignment of the human gene for acid alpha-glucosidase to chromosome 17. 38 44

The major maltase activity was found in the kidneys, followed by liver, muscle and blood. Only low maltase activity has been found in adipose tissue, muscle, and brain. The pH-optimum of kidney maltase was at pH = 6.0, the Michaelis-Menten Constant was measured to be 15.6 X 10(-3) mol/l. Even with a dose of 200 mg maltose/100 g body weight saturation of the hydrolysing system could not be attained in living rats. In nephrectomized rats the maltose oxidation was reduced to 55%. Only 0.2% of the applied maltose is excreted into the bile. According to our results the following main pathway of metabolism of maltose is suggested: glomerular filtration of maltose, hydrolysis of maltose to glucose by maltases which are localized in the membrane of the kidney brush borders, absorption of glucose, oxidation of glucose to CO2. In addition an extrarenal maltase activity is considered in the liver. The metabolism of injected trehalose was only 10% when compared with the metabolism of maltose.
Z Ernahrungswiss 1979 Sep
PMID:[Localization of the degradation of injected maltose]. 39 62

The pH optima and apparent Km and Vmax values were determined for nine glycosidases of the retinal pigment epithelium (RPE) of the calf. In terms of micromoles of substrate cleaved per milligram protein per hour, the following relative order of enzymatic activities was observed: beta-N-acetylglucosaminidase greater than alpha-glucosidase = beta-N-acetylgalactosaminidase greater than alpha-mannosidase greater than beta-galactosidase greater than beta-glucosidase greater than alpha-fucosidase greater than alpha-galactosidase greater than beta-glucuronidase. The pH optimum of each of these enzymes was in the acidic range (below pH 6). All these findings refer to enzymatic activities of bovine RPE preparations obtained by the brushing procedure of Glocklin and Potts and washing as described by Berman and Feeney. Thus they may relate to those activities associated with particulate components of the RPE cell and not to the more soluble glycosidases. The distribution of the glycosidases between the washes of the cells and the final pellet of bovine RPE cells was examined. The activities of 10 glycosidases in the RPE of the embryonic chick were also examined. Neither beta-mannosidase nor beta-fucosidase activities could be detected in washed bovine RPE cells, although beta-mannosidase was detected in RPE of the embryonic chick. The presence of isoenzymes of beta-glucuronidase in bovine RPE was indicated. Specificity by beta-glucuronidase of bovine RPE for synthetic substrates was observed.
Invest Ophthalmol Vis Sci 1978 Sep
PMID:Glycosidases of the retinal pigment epithelium. 70 Sep 67

Intravenous infusions of maltose were performed using human volunteers. Four volunteers received maltose in a dose of 0.25 g/kg bodyweight and hour during eight hours. A follow-up period of three hours was added. Six volunteers received maltose in a dose of 0.125 g/kg bodyweight and hour during twelve hours. Only with the lower dose of maltose (0.125 g/kg b.w.) a steady state is reached after six hour continuous infusion. However even under these conditions maltose concentration in blood reaches the high concentration of 70 mg/100 ml. Using the double infusion rate, no steady state is attained when the infusions lasted for eight hours, despite maltose concentration in blood measured 150 mg/100 ml at this time. By measuring different metabolic parameters (fatty acid concentration, phosphate concentration) it is shown that parenterally applicated maltose is metabolized in the human. On the other hand, adverse reactions were not observed. The concentrations of uric acid and bilirubin remain constant and the activity of SGOT is not altered. Renal excretion of sugar measures 25-35% of the maltose administered parenterally. It is concluded that the glucose in urine stems from direct intra tubular hydrolysis of maltose achieved by the neutral maltase of the kidneys. The lack of attaining constant blood concentration for maltose during the infusions and the high renal loss of sugar shows that maltose is not suited as the single substrate for parenteral nutrition. However, there remains the possibility to use maltose in combination with glucose substitutes. The metabolic behaviour of maltose is similar to glucose, it differs from glucose substitutes.
Z Ernahrungswiss 1976 Sep
PMID:[Tests with human volunteers on parenteral utilization of maltose]. 96 14

The effects of fasting were examined on the rhythmic changes in the activities of maltase [EC 3.2.1.20] and leucine aminopeptidase [EC 3.4.11.1] in the small intestine of rats which has been kept under scheduled feeding conditions. Irrespective of whether the rats had been kept on a daytime or nighttime feeding schedule, the rhythms of maltase and leucine aminopeptidase persisted when the animals were starved. However, the amplitude of the leucine aminopeptidase rhythm began to decrease from the first day of fasting, while that of maltase did not. Conspicuous rhythms persisted for at least 2 days during fasting, but they gradually became vague and disappeared after 5 days. When rats were refed after fasting, the leucine aminopeptidase activity increased within a few hours, but the maltose activity did not. It is suggested that the rhythms of the digestive enzymes in the small intestine of rats are not a direct consequence of food intake, but are triggered off by the anticipatory mechanism which operates when rats expect to be fed. The rhythmic change of leucine aminopeptidase seemed to be intensified by food intake.
J Biochem 1976 Sep
PMID:Circadian rhythms of digestive enzymes in the small intestine of the rat. II. Effects of fasting and refeeding. 97 54

In this study we investigated the function of the obstructed small bowel of the rat, the behaviour of the mucosal enzymes, the metabolic changes of the small bowel wall and the morphology of the mucosa. We found a decrease of passive transport of 3H-Antipyrine which was equal after 24 and 48 hrs. The active transport of 14C-Glucose was found to be progressively inhibited after occlusion. The metabolic enzymes SDH, G-6-PDH, and GOT remained unchanged, LDH was increased after 48 hrs, which can be explained by enzyme induction. The lactate-pyruvate ratio in the tissue of the obstructed bowel was 3 times as high as in the controls. The brush-border enzymes maltase and especially the alkaline phosphatase are decreased with progressive obstruction, which probably is caused by diffusion into the lumen. By electron-microscopy there are no changes in the brush-border membrane but a swelling of mitochondria which is caused by hypoxia.
Langenbecks Arch Chir 1975 Sep 10
PMID:[Functional and metabolic changes of the mucosa during the occlusion of the small bowel of the rat (author's transl)]. 121 48


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