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)

Two methods are described which allow the quantitative assay of the lysosomal enzyme alpha-1,4-glucosidase in single fibroblasts. In the first procedure the substrate was maltose, and liberated glucose was measured with an enzymatic cycling procedure for reduced nicotinamide adenine dinucleotide phosphate. Single cultured fibroblasts were found to have enzyme activities in the range of 0.5-10 X 10(-13) moles glucose/hr. In the second procedure the artificial substrate 4-methylumbelliferyl-alpha-D-glucopyransodie was used. It is hydrolyzed in a single step reaction to the fluorescent product 4-methylumbelliferone (MU). By reducing the incubation volume and by measuring the fluorescence in microdroplets with a microscope fluorometer, a sensitivity of 10(-14) moles MU could be obtained. Activities were found ranging from 0.5-10 X 10(-14) moles MU/hr/cell. Both procedures for single cell analysis proved to be reliable when compared with conventional assays on cell homogenates. Cocultivation and cell fusion studies were performed to demonstrate that these methods can be used to study the metabolic and genetic interaction between normal and enzyme-deficient fibroblasts derived from patients with glycogenosis II.
 ...
PMID:Methods for analysis of acid alpha-1,4-glucosidase activity in single hybrid cells. 106 91

In an attempt to detect acid maltase deficiency in neutrophils from patients with type II glycogenosis, without interference from the 'renal' alpha-glucosidase activity present in these cells, we have evaluated the contribution of the renal component in the total activity measured at pH 4.0 in extracts of human neutrophils. The renal contribution is about 13-25% and renal glucosidase appears to be closely related to the enzyme present on the epithelium of small intestine, which is known to be inhibited by Tris. We have used this compound as a selective inhibitor of the renal component of alpha-glucosidase activity measured at pH 4.0 in total extracts of neutrophils. Our results demonstrate that 0.1 mol/L Tris is an inhibitor of the renal alpha-glucosidase present in neutrophils and can be used to reduce the interference from this enzyme in assays of acid maltase.
 ...
PMID:Tris discriminates between the different alpha-glucosidase activities from extracts of human neutrophils. 152 88

Uncultured trophoblasts obtained from chorionic villus biopsy during the gestation period of 8-12 weeks were assayed for alpha-glucosidase activity using maltose as the substrate. Only one major form of maltase activity with a pH optimum at 4.0 was demonstrated. Using this method, we performed prenatal diagnosis on three pregnancies at risk for the infantile form of type II glycogen storage disease. Two affected fetuses and one unaffected fetus were predicted and the diagnosis was subsequently confirmed. The maltose assay offered a direct, simple, and sensitive method for prenatal diagnosis of Pompe's disease in the first trimester.
 ...
PMID:Prenatal diagnosis of Pompe's disease (type II glycogenosis) in chorionic villus biopsy using maltose as a substrate. 158 18

Muscular glycogenosis is a disease resulting from genetic abnormalities altering an enzyme which is involved in glycogen metabolism. In addition to disorders of glycogenolysis and glycolysis, there are other pathological processes such as acid maltase (alpha-glucosidase) deficiency and diseases associated with abnormal glycogen structure. Glycolysis is the only metabolic pathway that can produce ATP in the absence of oxygen. It is then easy to understand that any disturbance in this energy pathway can result in dysfunction of the muscle machine and in a number of symptoms which are common to these abnormalities. An overall review of the various diseases know to exist on the glycogenolytic and glycolytic pathway will enable the reader to acquire a better knowledge of their particular features.
 ...
PMID:[Muscular glycogenoses]. 189 12

A case of 25-year-old woman with glycogen storage myopathy is reported here. She was hospitalized for acute heart failure after alcohol drinking. The electrocardiogram on admission showed marked ST elevation. Laboratory data showed elevated levels of serum myogenic enzymes but no rise in cardiomyogenic enzyme: CK 3862 IU/l CK-MB 35 IU/l, LDH 427 IU/l, GOT 203 IU/l. After several days, she recovered from acute heart failure and could walk without supporting. ST elevation in ECG and elevated myogenic enzymes were also normalized. The occurrence of acute myocardial infarction was ruled out because a coronary angiogram and 99 Tcm scintigram were normal. Physical examination revealed proximal muscular weakness and mental retardation (WAIS, total 72). Venous lactate response was normal after semi-ischemic forearm exercise. PAS staining of muscle specimen showed an excess deposit of glycogen. Ragged-red fibers were not seen on Gomori-trichrome stain. By electron microscopy, a large amount of glycogen particles were demonstrated in the subsarcolemma, but there were no abnormal mitochondrial changes. Biochemical analysis showed accumulation of glycogen in muscles: 28.7 mg/g muscle (normal 11.4 +/- 4.2 mg/g muscle). The activities of enzyme in the pathway of glycogen and glycogenosis (alpha-glucosidase, amylo-1,6-glucosidase, phosphorylase a, phosphorylase kinase, phosphofructokinase, etc.) were within normal limits. The spectrum of glycogen iodine complex was normal. Our case was different from any type of muscle glycogen storage disease previously reported. The etiology of an excess of glycogen deposit in muscles is unknown.
 ...
PMID:[A case of glycogen storage myopathy with acute heart failure]. 220 34

Glycogen content and six major enzymatic activities involved in glycogen metabolism were analysed in chorionic villi (CV). Glycogen levels were found to be lower than those known to exist in liver and muscle. Activities of alpha-glucosidase, amylo-1,6-glucosidase, phosphorylase b and phosphorylase kinase were detectable by standard methods. The enzymatic activities of glucose-6-phosphatase and phosphorylase a were undetectable. These findings suggest that CV biopsies can be useful for first-trimester diagnosis of glycogen storage disease types II, III and VI, but not for type I (glucose-6-phosphatase deficiency).
 ...
PMID:Enzymatic activity of glycogen metabolism in chorionic villi. 302 29

In an attempt to elucidate the effect of metallic ions and EDTA on acidic alpha-D-glucosidase activity, we measured acidic alpha-D-glucosidase activity from either lymphocyte and muscle tissue homogenates or intact cells after incubation with metallic ions. The results showed that this enzyme activity was strongly inhibited by Ag+, Hg2+, and Fe3+ in either lymphocyte or muscle tissue homogenates. There was no effect of Zn2+, Cu2+, and Cd2+. However, intact cells, either lymphocyte or muscle cells, after incubation with Zn2+ for 1 or 2 hr, showed enhanced enzyme activity and suppression in the other metallic ion groups, especially in Ag+, Hg2+, and Fe3+. Since deficiency of this enzyme can cause type II glycogen storage disease (Pompe's disease), the more we understand the character of this enzyme, the more we can improve our enzymatic therapy.
 ...
PMID:Zinc can activate cellular acidic alpha-D-glucosidase activity. 314 35

A specific assay for acid alpha-glucosidase in urine was developed to facilitate the diagnosis of glycogenosis II. This enzyme activity was calculated as a difference between the alpha-glucosidase activities before and after immunoprecipitation with antiserum to acid alpha-glucosidase. Acid alpha-glucosidase accounted for 86% of the total activity in control urine. All the cases of various clinical types of glycogenosis II showed either a marked decrease or a complete deficiency of this enzyme activity. A marked decrease of acid alpha-glucosidase was demonstrated by immunoblotting of the urine from patients with late-onset forms of this disease. These results indicate that assays of urinary acid alpha-glucosidase by this immunological method are useful for detection of the various types of glycogenosis II.
 ...
PMID:A simple differential immunoprecipitation assay of urinary acid and neutral alpha-glucosidases for glycogenosis II. 330 22

Five cases of infant glycogen storage disease of the heart are reported. Their ages ranged from 2 to 7 months. They all presented with generalized hypotonia and respiratory tract infections. Four of the diagnosis were proven by skeletal muscle biopsy and enzymatic assay of alpha-1,4-glucosidase. All 5 infants had clinical signs of cardiac failure, cardiomegaly shown by chest X-ray, short PR intervals, severe left or bi-ventricular hypertrophy shown on electrocardiograms, increased thickness of the right and left ventricular walls and interventricular septum both on M-mode and two-dimensional echocardiograms and angiocardiograms. Four of them died during the follow-up period with a mean age at death of 7.5 months.
 ...
PMID:Clinical analysis of five infants with glycogen storage disease of the heart--Pompe's disease. 345 1

Pompe's disease (type II glycogenosis), an infantile form of generalized glycogenosis, is characterized biochemically by deficiency of lysosomal acid alpha-1,4-glucosidase and morphologically by intralysosomal glycogen storage in multiple organs, notably the central nervous system, heart, liver, and skeletal muscles. The endocrine system has not been described in detail in the literature. In two infants with Pompe's disease, intralysosomal glycogen was identified in the adrenal cortex and medulla, thyroid gland, parathyroid glands, pancreatic islets, and pituitary gland. Of special interest is the severe glycogen accumulation in the zona fasciculata of the adrenal glands.
 ...
PMID:The endocrine glands in Pompe's disease. Report of two cases. 389 54


<< Previous 1 2 3 4 5 Next >>