Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The paper describes a method using plasmid construction pSC11 for generation of recombinant vaccinia viruses supporting coexpression of heterologous genes and beta-galactosidase. The Ca2+-phosphate method of cell transfection by recombinant DNAs generated on the basis of pSC11, and selection of recombinant viruses from blue plaques of virus-infected cells in the presence of X-gala are reported at length.
 ...
PMID:[Methods of isolating and selecting recombinant vaccinia viruses expressing heterogenetic viral antigens]. 305 44

Antiserum raised against purified protein kinase C (the Ca2+/phospholipid-dependent enzyme) (Ballester, R., and rosen, O. M. (1985) J. Biol. Chem. 260, 15194-15199) was used to screen a rat brain cDNA library in the prokaryotic expression vector lambda gt11. Three positive clones were isolated and shown to have overlapping restriction endonuclease maps. The positive recombinant phage with the longest cDNA insert (1.4 kilobases (kb)) was used for production of a beta-galactosidase fusion protein. Rabbit antiserum raised against the fusion protein recognized a single rat brain polypeptide of Mr 80,000 which was identified as protein kinase C by the following criteria: electrophoretic co-migration with purified protein kinase C, partial co-purification with protein kinase C, and disappearance from the cytosol of phorbol 12-myristate 13-acetate-treated GH3 cells. The nick-translated cDNA hybridized with two mRNAs, 8 kb and 3.5 kb, whose tissue distribution was in agreement with that reported for protein kinase C activity. Hybrid selection with immobilized cDNA identified mRNA encoding a protein of Mr 80,000 that could be precipitated by antibody to purified protein kinase C. Treatment of GH3 cells with phorbol 12-myristate 13-acetate, which promotes translocation and subsequent degradation of protein kinase C, did not alter the level of either message.
 ...
PMID:A cDNA encoding protein kinase C identifies two species of mRNA in brain and GH3 cells. 309 80

Using a synthesized glycoprotein, beta-galactosidase modified with p-aminophenyl beta-D-galactopyranoside (beta-D-Gal beta-gal), the incorporation of the glycoprotein into bovine brain synaptosomes was studied. The uptake was mediated by a specific receptor to beta-D-galactoside, and was inhibited by GM1 ganglioside. The uptake was found to require energy and to be sensitive to metabolic inhibitors. Kinetic studies on beta-D-Gal beta-gal uptake indicated the presence of a saturable, carrier-mediated transport system in synaptosomes. By subcellular fractionation the beta-D-Gal beta-gal taken up was found in the fractions corresponding to the nucleus and membrane fragments, the soluble cytosomal fractions, and the mitochondria and lysosomes. The uptake was markedly increased by addition of Ca2+ to the incubation medium. The maximal uptake was obtained at pH 8.0 in the presence of 10 mM Ca2+ at 37 degrees C. By addition of a Ca2+ ionophore A23187, beta-D-Gal beta-gal uptake was increased in a dose-dependent way parallel to the increase in the intrasynaptosomal concentration of Ca2+. Preincubation of synaptosomes with calmodulin antagonists such as trifluoperazine and N-(6-aminohexyl)-5-chloro-1-napthalenesulfonamide (W-7) was found to inhibit the uptake markedly, and diazepam, an inhibitor of Ca2+/calmodulin-dependent protein kinase, also inhibited the uptake. At a concentration between 1 and 10 microM, 50% inhibition of the uptake was observed with either inhibitor. On the other hand, the addition of dibutyryl cyclic AMP did not affect the uptake of the glycoprotein into synaptosomes. These results suggest that the incorporation of this macromolecule is dependent on a Ca2+/calmodulin-dependent protein kinase.
 ...
PMID:Incorporation of glycosylated beta-galactosidase into bovine brain synaptosomes. 309 96

Although perfusion of the heart with calcium-free medium for a brief period followed by reperfusion with calcium-containing medium results in marked structural derangements (calcium paradox), the mechanisms for this cell damage are far from clear. Since activation of lysosomal enzymes has been associated with pathological damage, it was the purpose of this study to examine alterations in the activities of several lysosomal enzymes in rat hearts subjected to calcium paradox. No significant changes in the activities of beta-acetylglucosaminidase, beta-galactosidase, alpha-mannosidase, or acid phosphatase were seen in the homogenates of hearts exposed to the calcium paradox. However, there were dramatic alterations in the lysosomal enzyme activities in the sedimentable and nonsedimentable fractions during calcium paradox. The lysosomal enzyme activities were also detected in the perfusate collected during reperfusion with calcium-containing medium. These changes occurred during the reperfusion period since no alterations were apparent after calcium-free perfusion and were dependent upon the time of reperfusion with medium containing Ca2+ as well as the time of perfusion with Ca2+ -free medium before inducing Ca2+ paradox. These data indicate that alterations in lysosomal enzymes owing to reinstitution of calcium in Ca2+-deprived hearts may occur as a part of cardiac damage and general cellular disintegration.
 ...
PMID:Alterations in cardiac lysosomal hydrolases following induction of the calcium paradox. 344 82

A cDNA segment encoding the Ca2+-binding protein, parvalbumin, was isolated with the use of antibodies, from a lambda gtll expression library of Xenopus laevis tadpole poly(A)+ RNAs. The bacterially expressed beta-galactosidase-parvalbumin fusion protein of one lambda recombinant shows high affinity 45Ca2+ binding. The sequence of the tadpole parvalbumin is highly similar to previously characterized beta-parvalbumins of other organisms. Data from protein and RNA blotting experiments demonstrate that parvalbumin is absent in oocytes, eggs, and early staged embryos, and only becomes expressed during embryogenesis at the time of myogenesis. The protein can be detected in individual developing muscle cells and in muscle fibers of tadpole tail muscles. A simple method is also described for the isolation of neural tube-notochord-somite complexes from Xenopus embryos.
 ...
PMID:Expression of the Ca2+-binding protein, parvalbumin, during embryonic development of the frog, Xenopus laevis. 355 84

The plasma half-life of beta-galactosidase in rat was about 1.5 min. Ten minutes after in vivo injection, 45% of the enzyme was recovered in liver, with hepatocytes and endothelial cells as the predominant cell types responsible for uptake. In vitro uptake of beta-galactosidase in hepatocytes and nonparenchymal liver cells was saturable, Ca2+-dependent and it could be partly inhibited by mannose or alpha-methyl-mannoside.
 ...
PMID:Uptake and degradation of bovine testes beta-galactosidase by parenchymal and nonparenchymal rat liver cells. 393 48

Yersinia pestis strain KIM requires plasmid pCD1 for expression of the low calcium response, plague virulence antigen V, and virulence. We constructed Mu d1(Ap lac) insertion mutants of this plasmid which were unable to express the low calcium response. The insertions mapped to a 17-kilobase region of the plasmid. By determining the orientation of the insertions and examining beta-galactosidase production from the Mu d1 lac genes, we determined that this region contains three units of transcription, one of which is transcribed in a direction opposite the direction of transcription of the other two. Transcription of at least two of these units was induced significantly at 37 degrees C compared with 26 degrees C. Ca2+ (2.5 mM) and ATP (18 mM) had no significant effect on the level of expression of the Mu d1 lac genes of these mutants. All insertions in the region strongly reduced production of the V antigen. Insertions from each unit of transcription also reduced virulence in mice.
 ...
PMID:Genetic analysis of the low calcium response in Yersinia pestis mu d1(Ap lac) insertion mutants. 609 9

Urinary excretion of gamma-glutamyl transpeptidase, angiotensin I converting enzyme, beta-galactosidase and N-acetyl-beta-glucosaminidase was evaluated in 30 patients with idiopathic calcium oxalate urolithiasis. Higher than normal values were observed and the excretory enzyme pattern suggested tubular damage in patients with stones. A parallel study in the rat showed that an oxalate surcharge can promote increased urinary excretion of these enzymes. It is known that urothelium injury may enhance crystal adhesion. If the damage is primary it may be viewed as a promoting factor. If it is secondary it may be considered a factor capable of increasing salt precipitation.
 ...
PMID:Increased urinary excretion of renal enzymes in idiopathic calcium oxalate nephrolithiasis. 613 62

Dissociated sponge cell system has proved to be a useful model to study the process of cell aggregation both on cellular and subcellular level. The purpose of this review is to discuss recent results obtained from experiments with the marine sponge Geodia cydonium. Dissociated cells form functional aggregates during a process which can be sub-divided into three phases: first, formation of small primary aggregates in the presence of Ca2+; second, formation of secondary aggregates in the presence of an aggregation factor and third, reconstitution of a functional system of water-containing channels by rearrangement in the secondary aggregates. On subcellular level a series of macromolecules are known which are involved in the control of aggregation and separation of sponge cells: Aggregation factor, aggregation receptor, anti-aggregation receptor, beta-glucuronidase, beta-glucuronosyltransferase, beta-galactosyltransferase, beta-galactosidase and a lectin. These components might be linked in the following sequence: (a) Activation of the aggregation receptor by its enzymic glucuronylation; (b) Adhesive recognition of the cells, mediated by the aggregation factor and the glucuronylated aggregation receptor; (c) Inactivation of the aggregation receptor by its deglucuronylation with the membrane-associated beta-glucuronidase; (d) Cell separation due to either the loss of the recognition site (glucuronic acid) of the aggregation receptor for the aggregation factor or to an inactivation of the aggregation factor by the anti-aggregation receptor. The activity of the anti-aggregation receptor is most likely controlled by the Geodia lectin. The events leading to cell-cell recognition cause a change in the following metabolic events: Increase of oxygen uptake, decrease of cyclic AMP level, increase of cyclic GMP level and stimulation of programmed syntheses.
 ...
PMID:Sponge cell aggregation. 624 12

Using RNA-directed synthesis of the alpha-peptide of beta-galactosidase as an assay, a factor was purified that inactivated further function of the mRNA. In the presence of Ca2+ ions to inhibit most nuclease activity, inactivation of mRNA occurred during incubation with ribosomes or with a 1 M KCl wash of ribosomes. The inactivation activity required Mg2+ ions, and purified as a single factor which did not bind to DEAE-cellulose, but bound reversibly to phosphocellulose. The factor eluted from Sephadex G-150 with an apparent molecular weight of about 43,000. Purified 700-fold, it showed no detectable exonuclease activity, and little or no cleavage of a variety of single-stranded substrates, including full length lac operon mRNA; but repurified inactivated mRNA was still inactive for protein synthesis. The factor did not inhibit poly(U)-directed polyphenylalanine synthesis. When proteins isolated from the ribosomal wash were individually tested, highly purified RNase III, which purifies in the same way and has the same size, also inactivated lac mRNA. The ribosomal wash from an RNase III- strain showed little if any activity compared to that from an isogenic RNase III+ strain. The possibility of a site-specific inactivating cleavage of mRNA by RNase III at or near the 5' end is considered.
 ...
PMID:Functional inactivation of lac alpha-peptide mRNA by a factor that purifies that Escherichia coli RNase III. 625 91


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>