Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Coproduction of alpha-amylase, beta-amylase, amyloglucosidase, cellulase, xylanase, pectinase and beta-galactosidase by Sclerotium rolfsii was studied on various polysaccharides. Starch induced alpha-amylase, beta-amylase, amyloglucosidase and beta galactosidase; cellulose induced cellulase, xylanase, pectinase and beta-galactosidase; and pectin induced pectinase and beta-galactosidase. None of the enzymes studied except beta-galactosidase were induced on xylan. Group controlled mechanism for production of carbohydrases by Sclerotium rolfsii is suggested.
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PMID:Production of carbohydrases by Sclerotium rolfsii. 128 2

The effect of induction level of the bacteriocin release protein (BRP) on cell growth characteristics, protein expression, and protein release in a recombinant strain of Escherichia coli RR1 was investigated. Mitomycin C, the inducing agent, when added to the growth medium in moderate amounts (up to 200 ng/mL) was observed to enhance the release of periplasmic proteins from the cell to the fermentation broth substantially. The percentages of release of the proteins alpha-amylase and beta-lactamase were increased by factors of about 7 and 3, respectively, upon induction of the BRP. The percentage of alpha-amylase released into the broth increased from only about 5% to almost 50% with the aid of BRP. The cell growth curve and low extracellular activity of the cytoplasmic protein beta-galactosidase were indicative that cell lysis did not occur in an appreciable amount at a low induction level, with a mitomycin C concentration of less than 300 ng/mL.
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PMID:Protein release in recombinant Escherichia coli using bacteriocin release protein. 136 93

A host-vector system was established in Lactobacillus helveticus with beta-galactosidase activity as a selection marker. Plasmid pBG10 was constructed by joining the beta-galactosidase gene from L. bulgaricus, the promoter region of the erythromycin resistance gene from pAM beta 1, the replication region of pBR329, and the replication region of the L. helveticus cryptic plasmid pLJ1. L. helveticus SBT2195 (Lac- mutant), transformed with pBG10, was selected on skim milk plates. The structural gene of alpha-amylase (1536 bp) from Bacillus licheniformis, inserted downstream of the promoter region of the erythromycin resistance gene of pBG10, was expressed in L. helveticus SBT2195. Plasmid pBG10 is a food-grade and expression vector in L. helveticus.
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PMID:Establishment of a host-vector system in Lactobacillus helveticus with beta-galactosidase activity as a selection marker. 136 95

The alpha-amylase gene (amy) from Streptomyces griseus IMRU 3570 and the beta-galactosidase gene (lac) from S. lividans were subcloned into Brevibacterium lactofermentum or B. lactofermentum/Escherichia coli shuttle vectors. The amy gene was not expressed in B. lactofermentum from its own promoter but was efficiently expressed when the promoter of the kanamycin resistance gene (kan) was inserted upstream of the promoterless amylase gene. The lac gene from S. lividans was subcloned without its native promoter and was expressed when placed downstream of pBL1 promoters P2 or P3. The alpha-amylase was secreted extracellularly by removal of the same 28-amino acid leader peptide as in S. lividans. The amy and lac genes provide useful markers for selection of transformants and will facilitate the study of protein secretion in B. lactofermentum.
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PMID:Expression of Streptomyces genes encoding extracellular enzymes in Brevibacterium lactofermentum: secretion proceeds by removal of the same leader peptide as in Streptomyces lividans. 136 60

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.
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PMID:D-[3H]galactose incorporation into glycogen in retinal cone cells. 231 72

The inhibitory action and mechanism of inhibition of two types of alpha-glucosidase inhibitors, acarbose (Bay-g-5421) and 1-deoxynojirimycin derivatives (Bay-m-1099 and Bay-o-1248), on small intestinal carbohydrases (sucrase, isomaltase, glucoamylase, trehalase and lactase) and pancreatic alpha-amylase were compared in vitro using small intestinal brush border membranes and pancreatic homogenates from adult Sprague-Dawley rats. Acarbose at a low (4 microM) concentration strongly inhibited the activities of glucoamylase, alpha-amylase and sucrase (98, 68, and 63%, respectively). At a high (200 microM) concentration, isomaltase activity was also inhibited (28%); effects on trehalase and lactase activities were negligible. Both the 1-deoxynojirimycin derivatives were even more potent inhibitors of sucrase (Ki = 8.6 x 10(-8) M for Bay-m-1099;Ki = 5.0 X 10(-8) M for Bay-o-1248) than acarbose (Ki = 9.9 x 10(-7) M). Whereas glucoamylase activity was strongly inhibited by the 1-deoxynojirimycin derivatives, alpha-amylase activity was not. In contrast to acarbose, the 1-deoxynojirimycin derivatives at high concentrations (20-200 microM) inhibited considerably trehalase and lactase (a beta-galactosidase) activities. The inhibition of lactase activity was stronger by Bay-m-1099 (Ki = 4.9 X 10(-6) M) than by Bay-o-1248 (Ki = 6.7 X 10(-5) M). Where inhibition was seen, kinetic analysis showed fully competitive inhibition of sucrase, isomaltase, trehalase, glucoamylase and lactase by all three inhibitors.
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PMID:Inhibitory mechanism of acarbose and 1-deoxynojirimycin derivatives on carbohydrases in rat small intestine. 296 44

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.
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PMID:Intestinal first pass metabolism of amygdalin in the rat in vitro. 308 25

Culture filtrates and organic solvent extracts of over 500 freshwater and marine eukaryotic microalgae and cyanobacteria were screened for the presence of glycosidase inhibitors. Rapid colorimetric assays were used to detect inhibitors of alpha-glucosidase, alpha-amylase and beta-galactosidase. Inhibitors were found from 38 species. The results suggest that microalgae and cyanobacteria have potential as a source of glycosidase inhibitors which may have clinical applications.
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PMID:Microalgae and cyanobacteria as a source of glycosidase inhibitors. 311 66

Castanospermine, an inhibitor of alpha-glucosidase activity, was injected into rats to determine its effects in vivo. Daily injections of alkaloid, at levels of 0.5 mg/g of body weight, or higher, for 3 days decreased hepatic alpha-glucosidase to 40% of control values, whereas alpha-glucosidase in brain was reduced to 25% of control values and that in spleen and kidney was reduced to about 40%. In liver, both the neutral (pH 6.5) and the acidic (pH 4.5) alpha-glucosidase activities were inhibited, but the former was more susceptible. On the other hand, beta-N-acetylhexosaminidase activity was elevated in the livers of treated animals, whereas beta-galactosidase activity was unchanged and alpha-mannosidase activity was somewhat inhibited. Livers of treated animals were examined by light and electron microscopy and compared to control animals to determine whether changes in morphology had occurred. In treated animals fed normal rat chow, the hepatocytes were smaller in size and simplified in structure, whereas the high-glucose diet lessened these alterations. Furthermore, in those animals receiving castanospermine at 1.0 mg or higher per g of body weight for 3 days, there was a marked decrease in the amount of glycogen in the cytoplasm, while a large number of lysosomes were observed that were full of dense, granular material. That this dense material was indeed glycogen was shown by the fact that it disappeared when blocks of fixed tissue were pretreated with alpha-amylase. Glycogen levels in liver, as measured either colorimetrically or enzymatically, were somewhat depressed at the higher levels of castanospermine.
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PMID:Castanospermine inhibits alpha-glucosidase activities and alters glycogen distribution in animals. 388 59

Inhibition by low-molecular-weight sugars of precipitin line formation between a polysaccharide (EF) excreted by Leishmania tropica subsp. major, Leishmania enriettii, and rabbit antileishmanial antibodies on double gel diffusion plates revealed that galactose residues, possibly as components of lactosyl groups, were the critical immunodominant sugars mediating antibody recognition of EF. The galactose residues of the EF of L. tropica subsp. major were specifically labeled with tritium via galactose oxidase and sodium boro[3H]hydride. The radioactive EF had an apparent molecular weight of about 85,000 on sodium dodecyl sulfate-polyacrylamide gels and was precipitated by antileishmanial antibodies as well as Ricinus communis lectins I and II (galactose specific). Lectins specific for glucose-mannose residues, fucose, N-acetylglucosamine, and N-acetylgalactosamine did not precipitate the labeled EF. Treatment of [3H]EF with proteolytic (trypsin, papain, protease) or glycosidic (alpha-amylase, beta-galactosidase) enzymes had no effect on either the electrophoretic pattern of the material or on its recognition by antileishmanial antibodies or R. communis lectin. This resistance to enzyme activity suggests that EF may be a useful marker for the presence of the parasite in vivo if it can be detected in minute quantities.
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PMID:Identification of galactose as the immunodominant sugar of leishmanial excreted factor and subsequent labeling with galactose oxidase and sodium boro[3H]hydride. 617 74


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