Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The filamentous fungus Penicillium italicum when grown in a synthetic medium, produced and secreted 1,6-beta-glucanase into the culture medium. This enzyme has been partially purified by gel filtration. After this step the active fractions were free of 1,3-beta-glucanase, alpha-amylase and beta-glucosidase activities. Only four proteins, one associated with the enzyme, were found by polyacrylamide gel electrophoresis under non denaturing conditions. The enzyme behaves as an acidic protein (pI 4.65) with an optimum pH of 5 and an endohydrolytic mode of action. The activity was also found associated with the mycelium. Its synthesis was repressed by glucose or growth-promoting sugars. Derepression in low glucose containing medium required protein synthesis. 8-Hydroxyquinoline, an RNA synthesis inhibitor, added during the derepression period did permit some increase in the specific activity but prevented it when added at the beginning of that period.
 ...
PMID:Characterization and synthesis regulation of Penicillium italicum 1,6-beta-glucanase. 4 70

Intestinal mucosa and pancreas from purebred Beagle dogs were assayed for carbohydrase activity, using several methods of tissue treatment. The enzymes found and studied were alpha-amylase, sucrase, lactase, amyloglucosidase, cellobiase, maltase, and isomaltase. Experiments using polyacrylamide gel columns and heat inactivation showed the presence of an isozyme of maltase which degrades isomaltose. This activity had not been previously demonstrated in dogs. An optimal standard procedure is presented for the preparation and assay of canine digestive enzymes. A statistical analysis of variance of the results showed that the variance was primarily associated with differences among dogs and not by variance within the procedure. When the different extraction procedures were used, results indicated that the level of enzymes detected differed with the method of treatment.
 ...
PMID:Detection and definition of canine intestinal carbohydrases, using a standardized method. 88 14

Pseudorabies virus hemagglutinin was readily adsorbed on mouse erythrocytes at 4, 22, or 37 degrees C, but not on cattle erythrocytes. The adsorbed hemagglutinin could not be eluted from the cells by resuspending in phosphate-buffered saline (PBS), by incubating at 37 or 50 degrees C, or by incubating in the presence of neuraminidase. The receptor on mouse erythrocytes for the hemagglutinin was inactivated by trypsin, but not by neuraminidase, sodium deoxycholate (DOC), potassium periodate (KIO4), dithiothreitol (DTT), 2-mercaptoethanol (2-ME) and formalin. The hemagglutinin was inactivated by trypsin, alpha-amylase, pepsin, DOC, KIO4, and ethylendiamine-tetraacetic acid (EDTA), but not by papain, beta-glucosidase, phospholipase C, neuraminidase, DTT, 2-ME, Tween-80, ethylether, chloroform, trichloro-trifluoroethane, beta-propiolactone and formalin, suggesting that the hemagglutinin active component involved glycoproteins. The hemagglutinin was stable at 37 degrees C for lower temperatures but not at 60 degrees C or higher. The hemagglutinin activity was resistant to ultraviolet irradiation, while the infectivity was very susceptible. The hemagglutinin and the infectivity were readily sedimented by ultracentrifugation at 48,000 x g for 3 hr. In rate zonal centrifugation of the preparation on a sucrose density gradient, the hemagglutination (HA) activity showed a sharp peak at 1.22 g/ml coinciding with the peak of infectivity. The HA activity in the peak fraction seemed to be structually associated with virus particles. After fractionation of the virus by Nonidet P-40, the HA activity was found only in the fraction of the envelope material, indicating that the hemagglutinin is situated in the viral envelop.
 ...
PMID:Physicochemical properties of pseudorabies virus hemagglutinin. 166 85

This study was undertaken to measure the liberation in vitro of ellagic acid [2], a naturally occurring inhibitor of carcinogenesis, from precursor ellagitannins under conditions found in the gut tract. Enzymes, namely beta-glucosidase, esterases, and alpha-amylase, were incubated with raspberry extract. In addition, raspberry extract and casuarictin [1] were treated at different pH's and with the contents of small intestine and cecum from rats fed AIN-76A diet. The esterase activity of the enzyme samples was measured spectrophotometrically using p-nitrophenol acetate as the substrate, and the amount of ellagic acid [2] released from all samples was analyzed by hplc. The hydrolysis of the ellagitannins was not catalyzed by any of the purified enzymes tested, and components of the raspberry extract were found to inhibit the purified esterases noncompetitively. Casuarictin [1] was hydrolyzed to yield high quantities of ellagic acid [2] when placed in buffer at pH 7 and 8, or when incubated with cecal contents for two hours. The release of ellagic acid [2] from the raspberry extract was optimal at pH 8, and maximal release in cecal contents occurred with 1 h. Small intestinal contents had no significant effect on ellagic acid liberation from either casuarictin [1] or raspberry extract.
 ...
PMID:The effects of pH and rat intestinal contents on the liberation of ellagic acid from purified and crude ellagitannins. 179 80

Previous studies have shown that bovine retinas incubated with [3H]galactose incorporated it, unmodified, into large molecules. Light and electron microscope autoradiography showed a significant proportion of the label to be in cone inner segments, and pulse-chase studies showed it was subsequently transported to the synaptic pedicles. In this report, evidence is presented to show that the galactose-labelled macromolecules are resistant to hydrolysis by proteolytic enzymes, testicular hyaluronidase, chondroitinase ABC, beta-glucosidase and beta-glucuronidase, but are readily degraded by alpha-amylase and beta-galactosidase, and to a lesser extent by beta-amylase. Treatment with alpha-amylase also leads to specific removal of radioactivity from cone inner segments and pedicles, as judged by light-microscopic autoradiography. These studies appear to indicate that the cone-specific galactose label is in glycogen or glycogen-like molecules.
 ...
PMID:D-[3H]galactose incorporation into glycogen in retinal cone cells. 231 72

The intestinal first pass metabolism of amygdalin has been investigated in rat small intestine in vitro. The results show that amygdalin is hydrolyzed to prunasin, essentially in the wall of the proximal jejunum. This specific beta(1-6)hydrolytic cleavage of the terminal glucose residue is pH-dependent and can be inhibited by glucono-delta-lactone, a potent inhibitor of the lysosomal beta-glucosidase of the rat intestine. No substrate competition between phloridzin and lactose vs amygdalin was noted. None of the more common soluble beta- or alpha-enzymatic activities of mammalian intestine (alpha-glucosidase, alpha-amylase) or mammalian liver (beta-galactosidase, beta-glucuronidase) were capable of catalyzing the hydrolysis of the terminal glucose from amygdalin at pH's 5.0, 7.0 or 9.0. Furthermore, no metabolic activity of isolated rat livers toward amygdalin and prunasin was observed within two hours of recirculating perfusion. However, cecal contents of conventional rats, exhibited both amygdalin- and prunasin-hydrolyzing activities. The resulting mandelonitrile dissociates spontaneously into cyanide and benzaldehyde. Therefore, our findings indicate that metabolism of amygdalin to prunasin occurring in the proximal part of jejunum is apparently mediated by enzymatic beta(1-6)glucosidase activity of the gut wall. In contrast, the toxicity of amygdalin due to the release of cyanide obviously requires microbiological activities of the gut flora.
 ...
PMID:Intestinal first pass metabolism of amygdalin in the rat in vitro. 308 25

The pseudo-oligosaccharides, validamycins, showed potent inhibitory activity against trehalase of Rhizoctonia solani while no significant inhibition was exhibited against cellulase, pectinase, chitinase, alpha-amylase, alpha- and beta-glucosidases. In particular, validoxylamine A strongly inhibited trehalase in a competitive manner with a Ki value of 1.9 X 10(-9) M. The uptake of the antibiotic into the cell and the amount of the intracellular trehalose were investigated by incubating the washed mycelia of R. solani with validamycins. It was found that validamycin A is transported into the cell and hydrolyzed therein by a beta-glucosidase yielding validoxylamine A with greater inhibitory activity. Also validamycin A containing beta-D-glucosyl residue is more favorably taken up into the cell than validamycin D containing alpha-D-glucosyl residue or their common aglycone, validoxylamine A. In addition, validamycin A suppressed the in vivo degradation of the intracellular trehalose at very low concentration of 0.1 microgram/ml.
 ...
PMID:Effect of validamycins on glycohydrolases of Rhizoctonia solani. 358 21

A novel substrate, beta-2-chloro-4-nitrophenylmaltopentaoside (beta CNPG5), was used for the enzyme-coupled determination of alpha-amylase in biological fluids. It was hydrolyzed specifically by alpha-amylase to about 90% producing beta-2-chloro-4-nitrophenylmaltoside (beta CNPG2) and maltotriose. Under the assay conditions, the absorption of 2-chloro-4-nitrophenol (CNP) generated by the secondary reaction of alpha-glucosidase and beta-glucosidase as auxiliary enzymes is about twice the absorption of 4-nitrophenol (PNP), which is the end product currently measured in some alpha-amylase assay methods. The sensitivity of the assay using beta CNPG5 was thus much higher than that using 4-nitrophenyl-maltopentaoside (PNPG5) as substrate. The absorption of CNP did not fluctuate with temperature or with pH between 6.8 and 7.2, which are the conditions normally used for determination of amylase activity in biological fluids.
 ...
PMID:Determination of alpha-amylase in biological fluids using a new substrate (beta-2-chloro-4-nitrophenyl-maltopentaoside). 387 77

In the course of screening amylase inhibitor producing, microorganisms, a strain identified as Streptomyces nigrifaciens NTU-3314 was found to have the highest inhibitor-producing ability among the other isolated strains. This strain was aerobically cultured at 30 degrees C in a 5l jar fermentor with a working volume of 2l. The optimum cultural medium consisted of defatted soybean flake 3.0%, potato starch 4.0%, casein 0.6%, sucrose 0.6%, serine 0.02% and NaCl 0.8% (pH 7.0). With an aeration rate of 1.5 vvm, an agitation speed of 300 rpm and an inoculum of 15% seed (previously grown in seed medium 3), the highest amount of inhibitor was obtained after 24 hours of cultivation. The amylase inhibitor produced had inhibitory effects on both alpha-amylase and glucoamylase, but not on beta-amylase, alpha-glucosidase, beta-glucosidase or dextranase. It was quite stable in 0.1M phosphate buffer (pH 7.0) and nearly 100% of its activity was retained even after boiling at 100 degrees C for 20 min.
 ...
PMID:The microbial production of amylase inhibitor and its application. I. Isolation and cultivation of Streptomyces nigrifaciens NTU-3314. 608 1

With several isolates of T. aquaticus rotund bodies (rbs) have been artificially induced. The most active agents were lysozyme, pronase (not trypsin), cellulase (not alpha-amylase or beta-glucosidase), penicillin and some mineral salts. Two modifications of rbs were observed: the vesticular type arising from single cells or filaments and the aggregate-rbs resulting from secondary associations of several cells or filaments. In both cases the primary event is a partial detachment of the outer layer of cell envelopes followed by its swelling to form a hyaline bleb. Within these osmotically stable blebs cells and/or filaments involved in the ribs production become irreversibly trapped. Appearance of filaments and rbs in stationary phase cultures are discussed as a consequence of unbalanced growth culminating in abnormal autolytic reactions.
 ...
PMID:[Experimental induction of rotund bodies in Thermus equaticus]. 615 8


1 2 3 4 5 Next >>