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)

ABSTRACT Iron is an essential element for biological systems. There is increasing evidence that excess iron supplementation results in the deposition of iron in the duodenum and enhances mucosal injury and cell proliferation in the colon and cecum. In the present study we examined whether chronic exposure to high levels of iron fortification affects the functional integrity of the small intestine, especially the activities of various brush border enzymes. Wistar rats were fed iron 29 mg/kg body weight (or 6.58 mg/kg Fe) daily in the form of FeSO(4).7H(2)O for 39 days. The activities of brush border alkaline phosphatase (AP) (p < 0.001), sucrase (p < 0.01), maltase (p < 0.05), lactase (p < 0.05), and trehalase (p < 0.001) were reduced in purified membranes in iron-fed animals compared to controls. However, the activities of leucine amino peptidase (LAP) and gamma-glutamyl transpeptidase (gamma-GTP) were unaffected under these conditions. Analysis of alkaline phosphatase activity across the crypt-villus unit revealed a significant decrease (p < 0.05) all across the crypt-villus length, while sucrase activity was reduced (p < 0.01) only in the midvillus axis in iron-exposed animals. Kinetic studies showed a decrease in V(max) of AP from 1.11 to 0.83 units/mg protein and for sucrase from 0.77 to 0.43 units/mg protein in iron-fed rats, with no change in the apparent K(m) of the enzymes (AP, 8 mM; sucrase, 10 mM). Western blot analysis corroborated these findings. These results indicate that chronic iron exposure alters the activities of brush border enzymes, resulting in intestinal dysfunctions.
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PMID:Effect of chronic iron ingestion on the development of brush border enzymes in rat intestine. 2002 Sep 42

Actinoplanes sp. SE50/110 is known as the producer of the alpha-glucosidase inhibitor acarbose, a potent drug in the treatment of type-2 diabetes mellitus. We conducted the first whole transcriptome analysis of Actinoplanes sp. SE50/110, using RNA-sequencing technology for comparative gene expression studies between cells grown in maltose minimal medium, maltose minimal medium with trace elements, and glucose complex medium. We first studied the behavior of Actinoplanes sp. SE50/110 cultivations in these three media and found that the different media had significant impact on growth rate and in particular on acarbose production. It was demonstrated that Actinoplanes sp. SE50/110 grew well in all three media, but acarbose biosynthesis was only observed in cultures grown in maltose minimal medium with and without trace elements. When comparing the expression profiles between the maltose minimal media with and without trace elements, only few significantly differentially expressed genes were found, which mainly code for uptake systems of metal ions provided in the trace element solution. In contrast, the comparison of expression profiles from maltose minimal medium and glucose complex medium revealed a large number of differentially expressed genes, of which the most conspicuous genes account for iron storage and uptake. Furthermore, the acarbose gene cluster was found to be highly expressed in maltose-containing media and almost silent in the glucose-containing medium. In addition, a putative antibiotic biosynthesis gene cluster was found to be similarly expressed as the acarbose cluster.
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PMID:Comparative RNA-sequencing of the acarbose producer Actinoplanes sp. SE50/110 cultivated in different growth media. 2314 1


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