Search results for "Glucosidases"
showing 6 items of 26 documents
Molecular Epidemiological Survey ofCitrobacter freundiiMisidentified asCronobacterspp. (Enterobacter sakazakii) andEnterobacter hormaecheiIsolated fr…
2011
A total of 75 powdered infant milk formula (PIF) samples collected from pharmacies and drugstores in Western Sicily, Italy, and representative of 12 different brands were analyzed in this study to evaluate their microbiological quality. According to the U.S. Food and Drug Administration protocol, 32 samples out of 75 were contaminated by enterobacteria. Commercial biochemical API(r) 20E-system identification method indicated that six PIF samples were presumptively contaminated by Cronobacter spp., but further characterization by alpha-glucosidase based polymerase chain reaction (PCR) assay identification strongly suggested that these strains did not belong to the genus Cronobacter. Phylogen…
Construction and expression of a dual vector for chemo-enzymatic synthesis of plant indole alkaloids inEscherichia coli
2010
A dual vector (pQE-70-STR1-SG) containing coding regions of strictosidine synthase (STR1, EC 4.3.3.2) and strictosidine glucosidase (SG, EC 3.2.1.105) from the Indian medicinal plant Rauvolfia serpentina was constructed. Functional expression of the vector in Escherichia coli cells (M15 strain) was proven by isolation of prepurified enzyme extracts, which show both STR1 and SG activities. Incubation of the enzyme in the presence of tryptamine and secologanin delivered the indole alkaloid cathenamine, demonstrating functional co-expression of both STR1- and SG-cDNAs. Cathenamine reduction by sodium borohydride leading to tetrahydroalstonine revealed the chemo-enzymatic indole alkaloid synthe…
High speed X-ray analysis of plant enzymes at room temperature.
2013
X-ray measurements at room temperature (295 K) deliver high quality data sets with unprecedented speed (2 min), as shown for crystallized raucaffricine-O-β-D-glucosidase (RG), its mutant RG-Glu186Gln and several ligand complexes of the enzyme which participates in alkaloid biosynthesis in the plant Rauvolfia. The data obtained are compared with data sets measured under typical cryo conditions (100K). Under both conditions, density maps are highly comparable and favor the described protocol for room temperature measurements, potentially paving the way for future crystallographic studies capturing biosynthetic pathway intermediates.
Stimulation with carbachol alters endomembrane distribution and plasma membrane expression of intracellular proteins in lacrimal acinar cells.
2000
The events that lead to Sjogren's autoimmune processes in the lacrimal gland remain poorly understood. The acinar cell's responses to acute cholinergic stimulation include release of secretory products across the apical plasma membrane (apm) and a number of processes related to traffic between endomembrane compartments and the basal-lateral plasma membranes (blm), such as recruitment of Na, K-ATPase, accelerated recycling, and accelerated transcytosis of secretory IgA. We tested the hypothesis that stimulation-induced acceleration of endomembrane traffic is accompanied by changes in compartmentation and increased blm expression of proteins that are normally sequestered in endomembrane compa…
Diagnostic efficacy of the fluorometric determination of enzyme activity for Pompe disease from dried blood specimens compared with lymphocytes-possi…
2009
Pompe disease is a rare, autosomal-recessive disorder which results from a defect in the lysosomal enzyme acid alpha-glucosidase (GAA). The onset of this disease is highly variable, with infantile types being the most severe. Traditionally, lymphocytes, fibroblasts or muscle biopsies were necessary for enzyme activity measurement, because these materials do not express maltase-glucoamylase (MGA) that interferes with the assay. Recently, acarbose was found to inhibit MGA activity selectively, so that dried blood became accessible for GAA assessment.To evaluate the diagnostic efficacy of GAA measurement in dried blood specimens (DBSs) in comparison with lymphocytes. If DBSs provided reliable …