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)

Portions of closed jejunal biopsies from the dog were homogenised and their organelles separated by isopycnic centrifugation on continuous sucrose density gradients. The distributions of marker enzymes for the principal organelles were determined using highly sensitive assay procedures. The following organelles, with assayed marker enzymes and modal densities between brackets were characterised: peroxisomes (catalase, 1.21); brush borders (zinc-resistant alpha-glucosidase, leucyl-beta-naphthyl-amidase, gamma-glutamyl transferase, alkaline phosphatase, 1.20); lysosomes (N-acetyl-beta-glucosaminidase, alpha-mannosidase, 1.19); mitochondria (malate dehydrogenase, 1.18); endoplasmic reticulum (Tris-resistant alpha-glucosidase, 1.16); basal-lateral membranes (5'-nucleotidase, 1.11) and cytosol (lactate dehydrogenase). Homogenisation in isotonic sucrose containing digitonin (0.12 mmol/litre) selectively disrupted lysosomes and increased the equilibrium density of brush border and basal-lateral membranes. This procedure will be used to study the subcellular pathology of naturally occurring intestinal disease in the dog.
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PMID:Subcellular fractionation studies on peroral jejunal biopsies from the dog. 3 Jan 25

The yeast alpha-mannosidase [EC 3.2.1.24] was purified 1160-fold from the crude extract of the autolysate. The purified preparation was practically free from alpha-glucosidase, beta-glucosidase, alpha-galactosidase, beta-galactosidase, beta-mannosidase, and beta-N-acetylhexosaminidase activities. After the separation of yeast mannan during the purification procedures the enzyme became unstable but could be stored at 5 degrees C for three weeks with 50% loss of activity. The purified enzyme hydrolyzed both aryl and alkyl mannosides, but hydrolysis of yeast mannan proceeded slowly. Yeast mannan and Zn2+ increased the enzyme catalyzed hydrolysis of p-nitrophenyl mannoside, whereas NaN3, monoiodoacetate and methyl alpha-D-mannoside acted as inhibitors. The molecular weight was estimated to be 450,000 by gel filtration.
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PMID:Purification and properties of alpha-mannosidase from bakers' yeast. 33 3

The roles of extracellular and intracellular mechanisms in the degradation of brush border proteins have been investigated by studying the small intestinal mucosa of dogs with naturally occurring exocrine pancreatic insufficiency. Peroral jejunal biopsies were homogenised and the organelles separated by isopycnic centrifugation on continuous sucrose density gradients. The distributions of marker enzymes for the principal subcellular organelles were determined in the gradients and related to the specific activities in the homogenates. There were increased activities of the brush border carbohydrases zinc-resistant alpha-glucosidase, maltase and sucrase in the pancreatic insufficient animals, but no change in lactase activity. The activity of gamma-glutamyl transferase was also higher in the affected group; the activities of two other brush border enzymes, alkaline phosphatase and leucyl-beta-naphthylamidase, however, were unaltered. These findings with an increase in the modal density of the brush border from 1.20 to 1.22 are consistent with an enhanced glycoprotein content of the microvillus membrane. There were also rises in the activities of lysosomal enzymes. N-Acetyl-beta-glucosaminidase activity was increased in the soluble fractions and the percentage latent enzyme activity was reduced, findings indicative of an increased fragility of the lysosomal membrane. There were no marked alterations in the activities or density gradient distributions of marker enzymes for the other organelles, stressing the specificity of the changes in the brush borders and lysosomes. These findings are compatible with the degradation of certain exposed brush border proteins by pancreatic proteases and suggest that when this is defective, intracellular degradative mechanisms may be stimulated.
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PMID:Biochemical changes in the jejunal mucosa of dogs with naturally occurring exocrine pancreatic insufficiency. 48 65

An investigation was conducted on the influence of the presence of zinc in an elemental diet on the mucosa of residual intestine after massive small bowel resection. A total of 34 male Sprague-Dawley rats were divided into five groups: control animals (n = 10) were killed after overnight fasting; a second group (n = 14) underwent massive small bowel resection preserving 10 cm of terminal ileum, and the third group (n = 10) underwent sham operation. Animals in the second and third groups were fed either a commercially available elemental diet or a zinc-deficient diet for 2 weeks; they were then killed. In animals receiving the zinc-deficient diet, a significant decrease (P < 0.05) was noted in plasma zinc and total protein, and in mucosal wet weight (duodenum), thickness (duodenum and ileum), and protein (duodenum) and DNA (duodenum) content. Mucosal sucrase and maltase specific activities in the duodenum and ileum fell but diamine oxidase levels did not. These results suggest that zinc plays an important role in intestinal adaptation in the rat, and indicate that this trace element is essential for intestinal mucosal preservation in this animal.
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PMID:Zinc-deficient diet impairs adaptive changes in the remaining intestine after massive small bowel resection in the rat. 142 69

A sucrose-inducible alpha-glucosidase activity that hydrolyzes sucrose in Candida albicans has been demonstrated previously. The enzyme is assayable in whole cells and was inhibited by both sucrose and maltose. A C. albicans gene (CASUC1) that affects sucrose utilization and alpha-glucosidase activity was cloned by expression in a Saccharomyces cerevisiae suc2 mutant (2102) devoid of invertase genes. CASUC1 enabled the S. cerevisiae mutant to utilize both sucrose and maltose. DNA sequence analysis revealed that CASUC1 encodes a putative zinc finger-containing protein with 28% identity to a maltose-regulatory gene (MAL63) of S. cerevisiae. The gene products of CASUC1 and MAL63 are approximately the same size (501 and 470 amino acids, respectively), and each contains a single zinc finger located at the N terminus. The zinc fingers of CASUC1 and MAL63 comprise six conserved cysteines (C6 zinc finger) and are of the general form Cys-Xaa2-Cys-Xaa6-Cys-Xaavariable-Cys-Xaa2-Cys-+ ++Xaa6-Cys (where Xaan indicates a stretch of the indicated number of any amino acids). Both contain five amino acids in the variable region. CASUC1 also complemented the maltose utilization defect of an S. cerevisiae mutant (TCY-137) containing a defined mutation in a maltose-regulatory gene. The sucrose utilization defect of type II Candida stellatoidea, a sucrase-negative mutant of C. albicans, was corrected by CASUC1. Determinations of alpha-glucosidase activity in whole cells revealed that activity was restored in transformants cultivated on either sucrose or maltose. To our knowledge, this is the first zinc finger-encoding gene, as well as the first putative regulatory gene, to be identified in C. albicans.
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PMID:A zinc finger protein from Candida albicans is involved in sucrose utilization. 172 10

Semen volume, pH, sperm characteristics and the ejaculate content of six compounds secreted by the epididymides, prostate and seminal vesicles are presented for several semen samples from 25 men (mean age 31 years) who, without clinical assistance, had fathered children within the previous 29 months. There was a large variation both within and between individual's samples for concentrations and amounts per ejaculate of all parameters except pH. The range including 96% of all values from these fertile men are presented as standards against which samples from infertile men could be compared. Lower limits (combined arithmetic means minus twice the combined within- and between-father standard deviation) were: for semen volume, 1.9 ml; for semen pH, 7.4; for total sperm count, 39 X 10(6); for normal morphological forms, 42%; for motility (WHO grades) a, 4%; b, 19%; c, 1%; d, 19%; for curvilinear velocity, 27 microns/s; for total glucosidase, 27 mU/ejaculate; for neutral alpha-glucosidase, 17 mU/ejaculate; for L-carnitine, 0.4 mumol/ejaculate; for glycerophosphocholine, 2.4 mumol/ejaculate; for fructose, 15 mumol/ejaculate; for citrate, 30 mumol/ejaculate; for zinc, 2.8 mumol/ejaculate.
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PMID:Variations in semen parameters from fathers. 175 26

To determine whether zinc has a specific role on weight gain and intestinal disaccharidase activity, 42 male Sprague-Dawley rats were assigned to one of seven groups (n = 6 each). These were a baseline control group (0) that was killed to analyze initial intestinal disaccharidase (sucrase and maltase) activity, a second group (A) fed a zinc-deficient diet for 1 week, a third group (B) pair-fed control for A, a fourth group (C) fed a zinc-deficient diet for 2 weeks, a fifth group (D) pair-fed control for C, a sixth group (E) fed a zinc-deficient diet for 3 weeks, and a seventh group (F) pair-fed control for E. All experimental groups received distilled deionized drinking water, whereas control groups received zinc-enriched (25 micrograms of zinc/ml) distilled deionized water. Water was given ad libitum. After killing, the mucosa of the proximal half of the small intestine was analyzed for protein and disaccharidase activity, and liver, kidney, and heart were analyzed for zinc concentration. Protein content and disaccharidase activity of the jejunal mucosa in the experiment and control groups did not differ significantly. However, animals on the zinc-deficient diet demonstrated mildly depressed growth rates that were proportional to the duration of the experiment, and significantly lower zinc concentration in the kidney in the experimental groups. The data indicate that administration of a zinc-deficient diet for up to 3 weeks did not result in significant changes in intestinal mucosa protein content or in disaccharidase activity.
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PMID:Effect of zinc-deficient diet of varying duration on intestinal disaccharidase activity in the rat. 232 70

We determined the complete nucleotide sequence of the yeast MAL6R gene from the Saccharomyces carlsbergensis MAL6 locus. The MAL6R gene encodes a transacting protein required for the inducible, coordinate expression of the two divergently transcribed structural genes, MAL6T (maltose permease), and MAL6S (maltase) at this locus. The transcription initiation sites for MAL6R were determined by primer extension experiments. The MAL6R gene contains an open reading frame of 473 amino acids with a calculated Mr of 54,892. The N-terminus of the deduced protein contains an amino acid sequence isologous to a consensus sequence for cysteine-zinc associated DNA binding fingers found in other fungal DNA binding proteins. The MAL6R gene was mapped to chromosome VIII by using OFAGE (orthagonal field alternating gel electrophoresis) gels and hybridization with specific chromosome and MAL6 probes.
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PMID:Primary structure of the regulatory gene from the MAL6 locus of Saccharomyces carlsbergensis. 285 10

Activities of the enzymes lactase, sucrase, maltase, alkaline phosphatase, and superoxide dismutase (SOD) were measured in mucosa of duodenum and ileum of the rat after 70% resection of mid-small intestine or sham operation (transection). We also measured the concentrations of zinc, copper, and manganese in several tissues to assess trace metal homeostasis postresection. Resection resulted in decreased specific activities of disaccharidases and alkaline phosphatase in duodenum, while specific activities remained unchanged in ileum. Specific activity of total SOD (the sum of Cu-Zn and Mn SOD) and Mn SOD was the same in duodenum after resection but was markedly increased in ileum. Tissue trace metal concentrations changed minimally. Because of postresection mucosal growth, total segmental activity of disaccharidases and alkaline phosphatase was the same in duodenum and increased in ileum of resected compared to transected rats. Segmental activity of total SOD and Mn SOD doubled in duodenum and trebled in ileum of resected as compared to transected rats. Thus, total segmental enzyme activity is maintained or increased postresection by increased enterocyte proliferation rate and mucosal growth.
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PMID:Adaptation of the duodenum and ileum of the rat to mid-gut resection: enzyme activity and trace metal status. 308 Aug 64

A previous study has shown that long-term feeding of ethanol in high doses (36% of total calories) causes marked changes in intestinal mucosal disaccharidase activity as well as blunting of the intestinal villi. To determine whether similar damage occurs in response to a more moderate ethanol exposure, we pair fed rats a liquid diet that provided 15.5% of total calories from ethanol for 5 weeks. In the proximal segment of the intestine, we found that ethanol did not affect the total activities of maltase (8.0 +/- 2.4 U vs. control value of 6.7 +/- 1.8 U), sucrase (1.5 +/- 0.5 U vs. control of 1.2 +/- 0.3 U), or lactase (125 +/- 42 mU vs. control of 107 +/- 36 mU). Similarly, we found no differences from control values for the three disaccharidases in the middle or distal small bowel. The mucosal protein content of the experimental animals did not differ from values found in the control animals. In addition, no change in intestinal villus height or crypt depth was detected. The zinc content of hair and serum was not affected by the ethanol feeding. We conclude that prolonged ingestion of a moderate dose of ethanol does not damage the small intestinal disaccharidase enzymes, mucosal protein content, or intestinal architecture.
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PMID:Effect of moderate prolonged ethanol ingestion on intestinal disaccharidase activity and histology. 308 74


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