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)

Previous studies have indicated that alpha-D-glucosidase activity is increased and exhibits abnormal properties in tissues from patients with cystic fibrosis (CF). In the present investigation serum alpha-D-glucosidase from patients with CF and from patients with chronic pulmonary disease (e.g. asthma and bronchiectasis) has been studied to determine the specificity of the alpha-D-glucosidase alteration(s) in CF sera. Both groups of patients have elevated alpha-D-glucosidase activity levels and similarly abnormal isoelectric focusing profiles with significantly less activity associated with acidic enzymatic forms (i.e. having isoelectric points below 4.8). These results suggest that the abnormalities of CF serum alpha-D-glucosidase may be secondary to chronic pulmonary disease and emphasize the importance of including appropriate pathological controls in biochemical studies on CF.
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PMID:Serum neutral alpha-D-glucosidase from patients with cystic fibrosis and chronic pulmonary disease. 388 49

The nature and origin of maltase activity present in amniotic fluid, and used as a marker enzyme in the prenatal monitoring of cystic fibrosis, has been studied. Using monoclonal antibodies against human intestinal disaccharidases and via heat inactivation experiments it is shown that the maltase activity found in amniotic fluids from pregnancies of 16-24 wk of gestational age originates completely from sucrase-isomaltase; no maltase-glucoamylase could be detected. With various monospecific antibodies the possible contribution of non-intestinal brush border enzymes to the total maltase pool could be excluded: neither renal nor lysosomal maltase appeared to be present.
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PMID:Characteristics of maltase activity in amniotic fluid. 388 2

Intestinal disaccharidases in amniotic fluid were studied in 41 pregnancies with a recurrence risk for cystic fibrosis (CF). In 11 out of 13 pregnancies with CF fetuses the maltase and sucrase activities were either below the control range (8 cases) or below the 10th percentile of control values (3 cases). Trehalase and lactase were slightly less informative indicators of CF. Of the other 28 pregnancies 3 had low amniotic fluid activities of several intestinal enzymes and were terminated, 12 resulted in the birth of a healthy child and 13 are continuing. The findings in fetal CF suggest an impairment of the defaecation of intestinal contents into the amniotic fluid. Reduced or low amniotic fluid disaccharidase activities were also found in other fetal disorders with demonstrated or presumed intestinal anomalies: e.g. anal atresia (2 cases), anencephaly (3 our of the 7 cases), trisomy 13 (5 cases), trisomy 18 (3 of the 5 cases) and trisomy 21 (19 of the 22 cases). Reduced amniotic fluid disaccharidase activities, although not specific for CF, are highly informative in pregnancies at high risk for CF. Using the 10th percentile of the normal range for amniotic fluid disaccharidase activities as an action line, the sensitivity of CF detection is estimated at 80 to 90 per cent, which could in high risk pregnancies reduce the risk of having another affected child from 1 in 4 to 1 in 20.
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PMID:Amniotic fluid disaccharidases in the prenatal detection of cystic fibrosis. 399 66

Activities of the microvillar enzymes gamma-glutamyltranspeptidase (GGTP), aminopeptidase M (APM), phosphodiesterase and maltase have been examined in second-trimester amniotic fluid as possible aids to the early prenatal diagnosis of cystic fibrosis (CF). The two peptidases, GGTP and APM, gave best results. If the fifth percentile of the normal range is used as an action line, the sensitivity of a positive test (low GGTP value) is 78% and the predictability 84%. At the tenth percentile the sensitivity is 100% and the predictability 77%. These approximate figures apply only to pregnancies where there has been a previous affected child. Until the primary protein defect in CF is discovered, this may prove an acceptable form of prenatal diagnosis to the high-risk mother.
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PMID:Prenatal diagnosis of cystic fibrosis by assay of amniotic fluid microvillar enzymes. 614 94

The enzyme activities of alpha-fucosidase (pH 4.0 and pH 5.5), alpha-galactosidase, beta-galactosidase, alpha-glucosidase (pH 4.5 and pH 6.0), beta-glucosidase, beta-glucuronidase, beta-hexosaminidase, and alpha-mannosidase (pH 4.5 and pH 5.5) were investigated in sera from cystic fibrosis (CF) patients. Several of these activities were significantly increased in sera from patients compared to age-matched control children. CF-patients in a more advanced stage of the disease had a tendency to higher values of some of these hydrolases than those in better condition. No new isoenzymes of these hydrolases were found. Only minor differences could be detected in the pH-profiles of alpha-mannosidase and acid phosphatase from age-matched normal controls, heterozygotes and homozygotes for CF. With our technique, alpha-mannosidase and acid phosphatase showed the same thermostability in CF-patients. CF-heterozygotes and age-matched controls, except at 56 degrees C, when the activity of acid-phosphatase in the plasma from adult CF-heterozygotes decreased more than that from adult controls
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PMID:Acid hydrolases in sera and plasma from patients with cystic fibrosis. 626 20

This study determined in a blind fashion the activity levels and thermostability properties of two lysosomal hydrolytic enzymes, acid phosphatase and alpha-mannosidase, in plasma samples from 25 cystic fibrosis (CF) patients and 25 age- and sex-matched normal controls. Mean alpha-mannosidase activity (3.2 +/- 1.0 mU/ml) and acid phosphatase activities (6.5 +/- 2.9 mU/ml) in CF patients were not significantly different from those found in normal individuals (2.8 +/- 0.7 and 7.6 +/- 3.4 mU/ml, respectively). Using stringent conditions no differences in thermostability properties of these enzymes were found between plasma from CF patients as compared to that of normal controls. When activity levels of these enzymes and of four additional hydrolytic enzymes, alpha-L-fucosidase, alpha-galactosidase, alpha-glucosidase and beta-galactosidase, were determined in submandibular saliva, no significant differences in enzyme levels between CF and age- and sex-matched controls were noted nor were thermostability differences found. Our data do not support the concept that altered properties of these enzymes are useful as markers for detection of CF homozygotes and heterozygotes, nor the hypothesis that the defect underlying this disease is a deficiency of post-translational modification of glycoproteins leading to their mis-compartmentalization and qualitative alteration.
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PMID:Plasma and submandibular saliva lysosomal enzymes in cystic fibrosis. 639 40

Nine lysosomal enzymes and alkaline phosphatase have been assayed in human pancreatic juice from controls and patients with chronic calcifying pancreatitis. Specific activities were evaluated by a nonparametric test (Wilcoxon) with a probability of 2 P less than or equal to 0.5. The values of acid phosphatase, alpha-glucosidase, beta-glucosidase and alpha-galactosidase are significantly higher in pathological juices; the values of alpha-mannosidase and beta-glucuronidase are also increased in the same patients but at the limit of significance. Alkaline phosphatase, beta-hexosaminidase and alpha-fucosidase follows the same trend but the values are not statistically significant between the two groups of patients. Studies on skin cultures of four patients with chronic calcifying pancreatitis demonstrate that the increased specific activities of lysosomal enzymes in the pathological juices do not correspond to a leakage of these enzymes into the extracellular space as described for cystic fibrosis.
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PMID:Alkaline phosphatase and acid lysosomal hydrolases in pancreatic juice and fibroblast cell cultures of patients with chronic calcifying pancreatitis. 680 85

The average activity levels of acid alpha-glucosidase are comparable in liver supernatant fluids for 15 cystic fibrosis patients and 12 controls (401 +/- 131 and 347 +/- 109 nmol/h/mg protein, respectively) and no significant differences were found for the cystic fibrosis and control liver acid alpha-glucosidases in their (a) apparent Km values for the 4-methylumbelliferyl substrate (1.1 mmol/l), (b) pH optima (4.2) and thermostability curves and (c) isoelectric profiles (one form with an isoelectric point of 4.5 +/- 0.2). In contrast, average neutral alpha-glucosidase activity levels were significantly increased (p less than 0.0002) in sera from 21 cystic fibrosis patients compared to 15 controls (10.7 and 2.7 nmol/h/ml). This increased activity is not due to (a) different stability upon storage at --20 degrees C, (b) the presence of activators in cystic fibrosis sera or inhibitors in normal sera (as determined by mixing studies), (c) altered Km values or (d) altered pH optima curves. Cystic fibrosis serum neutral alpha-glucosidase appears to be more thermostable and has a consistently altered isoelectric profile (greater percentage of activity above pI 4.8) when compared to the normal serum enzyme. This altered isoelectric composition may reflect changes in neutral alpha-glucosidase which contribute to its increased activity in cystic fibrosis sera.
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PMID:Activity levels and properties of acid alpha-glucosidase from liver and neutral alpha-glucosidase from sera of cystic fibrosis patients and controls. 703 May 25

The study concerns the maltase, saccharase, lactase and alkaline phosphatase activity in small intestinal biopsy specimens from 61 consecutively admitted, untreated, Caucasian cystic fibrosis patients. A group of 319 age matched controls admitted during the same time period for undefined gastrointestinal or nutritional disorders acted as the controls. In order to eliminate morphological damage as a confounding factor, the enzyme activities were studied in small intestinal biopsy specimens having both normal stereomicroscopic and histological features. It was shown that neither maltase nor saccharase activity was different in the two groups, in contrast to lactase and alkaline phophatase activity, that was significantly lower in cystic fibrosis patients. The differences could not be explained by the nutritional status as judged by the body mass index. Lactase activity is known to be easily affected by numerous enteropathies. As the information on alkaline phosphatase activity is limited, the low activity is discussed in more detail. Taking into account the literature data, the low alkaline phosphatase activity is tentatively attributed either to enhanced release from the brush border or to the faulty handling of alkaline phophatase protein in the post-golgi compartments secondary to the accumulation of incorrectly glycosylated CFTR in the same cell structures.
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PMID:Small intestinal brush border enzymes in cystic fibrosis. 1054 91

In 61 cystic fibrosis (CF) patients, the small intestinal mucosa was studied at the time of diagnosis before starting therapy. In 19 out of 61 patients, partial villous atrophy on light microscopy and shortened villi on stereomicroscopic examination were seen. On the biopsy specimens, maltase, sucrase, lactase and alkaline phosphatase activities were studied. Comparison of the enzymatic activities in CF patients having damaged mucosa and a group of patients having similar mucosal lesions of unspecified origin (UTID), reveals a significantly more pronounced decrease of the alkaline phosphatase activity (p < 0.005) in the CF patients. This is in agreement with previous reported results in CF patients with normal mucosa. The abnormal mucosal findings could be due to the decreased neutralization of the gastric content delivered into the duodenum, the early inflammatory reaction present in the CF mucosa and/or to the impaired synthesis of membrane glycoproteins and enzymes secondary to the CFTR mutation.
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PMID:Combined impact of mucosal damage and of cystic fibrosis on the small intestinal brush border enzyme activities. 1463 29


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