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

---

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

Direct comparisons are made between covalently linked streptavidin and silver ion coated microplates. Both coatings can immobilize biotinylated molecules. Silver ion coated microplate wells can immobilize 1.8 times higher amounts of biotin labeled horseradish peroxidase. The quantitation range and capacity for the capture of horseradish peroxidase using biotin labeled horseradish peroxidase are also greater for silver ion coated microplates. Approximately twice as many anti-horseradish peroxidase antibodies can be immobilized per well using silver ion coated microplates. Higher capacities are presumed to be due to the smaller footprint of silver ions as compared to streptavidin. A direct comparison between the two coatings for a beta-galactosidase ELISA showed that while the silver ion coated microplates gave higher readings, the streptavidin coated microplates exhibited smaller well-to-well variation. However, higher well to well variation for the silver microplates is attributed to the high density of anti-beta-galactosidase antibodies on the microplates and the weak binding of clone GAL-13 to beta-galactosidase, rather than the silver coating. These studies suggest silver ion coated microplates are a desirable alternative to streptavidin plates for quantitative immunoassays.
...
PMID:A comparison of silver ion to streptavidin coated microplates. 1116 40

We have shown that a deletion mutant form of Bcr [Bcr(64-413)] is a strong inhibitor of the tyrosine kinase of Bcr-Abl in vitro and also inhibits its oncogenic growth effects (Liu et al., Cancer Res., 56: 5120-5124, 1996). To determine the effects of this Bcr-Abl kinase inhibitor on chronic myelogenous leukemia (CML) cells, we cloned BCR(64-413) into a recombinant, replication-defective adenovirus to express useful quantities of Bcr(64-413) in a wide variety of cells in culture. Infection of Cos1 cells with plaque-purified virus at a multiplicity of infection of 20-40 induced high expression of Bcr(64-413) as detected by Western blotting. Infection of hematopoietic cells at modest multiplicities of infection (20-40) required special conditions involving shifting cycling cells to a nongrowing condition involving serum starvation and cell crowding. Under these conditions, both Bcr-Abl-positive and -negative hematopoietic cells can be efficiently infected by adenovirus, as demonstrated by 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside staining of cells infected by beta-galactosidase (beta-GAL) adenovirus. We found that expression of Bcr(64-413) in Bcr-Abl-positive K562 and BV-173 cells, but not Bcr-Abl-negative SMS-SB cells, increased cell-cell clumping and inhibited cell growth. In contrast to the effects of the Bcr(64-413) adenovirus, the beta-GAL adenovirus, despite infecting both types of cells, did not block growth or increase cell-cell clumping of Bcr-Abl-positive and -negative hematopoietic cells. Expression of Bcr(64-413) protein in primary cultures of cells from CML patients with active disease interfered with cell growth, induced apoptosis (as measured by annexin staining), and increased cell-cell clumping, whereas the beta-GAL adenovirus and mock-infected cells lacked these effects. In contrast, normal marrow cells did not exhibit these effects on infection with Bcr(64-413) adenovirus. We conclude from these findings that Bcr(64-413) interferes with the oncogenic effects of Bcr-Abl and therefore has the potential for use in therapy of CML.
...
PMID:Expression of a truncated first exon BCR sequence in chronic myelogenous leukemia cells blocks cell growth and induces cell death. 1119 51

The purpose of these studies was to explore the sex- and tissue-specific expression of the LH receptor (LHR) gene. Fusion genes containing three different lengths of the 5'-flanking region of the mouse LHR gene (7.4 kb, 2.1 kb, and 173 bp), beta-globin intron, and the beta-galactosidase (beta-GAL) reporter gene were constructed. Function of these fusion genes [LHR (7.4 kb)/beta-GAL, LHR (2.1 kb)/beta-GAL, and LHR (173 bp)/beta-GAL] was studied in vitro and in vivo. beta-GAL expression was higher in transfected mouse Leydig (mLTC-1) than in granulosa (KK-1) tumor cells with all three constructs. The shortest LHR (173 bp)/beta-GAL construct showed the highest level of beta-GAL expression in both cell types. beta-GAL expression was clearly suppressed with the 2.1-kb promoter and was nearly undetectable with the 7.4-kb construct. In transgenic mice, all three constructs directed beta-GAL expression to adult Leydig cells, displaying decreasing intensity with increasing promoter length. Unexpectedly, beta-GAL expression was also found in elongating spermatids, but not in fetal Leydig cells. There was no expression in any ovarian cell type with the three constructs used, except that one of five mouse lines with the LHR (7.4 kb)/beta-GAL construct expressed beta-GAL in their thecal cells. Two lines transgenic for the 7.4- and 2.1-kb promoter constructs each directed high beta-GAL expression to the brain, with higher intensity in 7.4-kb lines. All promoters directed expression to the pituitary gland, some faintly to the adrenal gland. Northern hybridization analysis of the beta-GAL transcripts in Leydig cells revealed that the 173-bp promoter mainly gave rise to the full-length beta-GAL messenger RNA, whereas the 2.1- and 7.4-kb promoters mainly induced transcription of truncated beta-GAL messages. This suggests that the 5'-flanking region, upstream of -173, determines the formation of splice variants of the structural gene to be transcribed. The present findings in transgenic mice provide in vivo evidence for basal transcriptional activity of the first 173 bp upstream of the LHR translation initiation codon. In conclusion, the promoter function of the mouse LHR 5'-flanking region is tissue, age, and sex specific. The sequence upstream of the basal promoter determines extragonadal LHR expression as well as the alternate splicing of its message. The promoter sequences directing LHR expression to fetal Leydig cells and ovary reside outside the 7.4-kb 5'-flanking region and remain to be identified.
...
PMID:Promoter function of different lengths of the murine luteinizing hormone receptor gene 5'-flanking region in transfected gonadal cells and in transgenic mice. 1135 91

We have cloned a cDNA fragment encoding a beta-galactosidase from Japanese pear (Pyrus pyrifolia) fruit (JP-GAL). It contained an untranslated sequence of 182 nucleotides at the 5' end, a presumptive coding sequence of 2,193 nucleotides and an untranslated sequence of 268 nucleotides including a polyadenylation signal and a poly (A) tail at the 3' end. It encoded a protein with a calculated molecular weight of 80.9 kDa which consists of 731 amino acids. Both the nucleotide and the deduced amino acid sequences showed a 98% sequence identity with that obtained from the apple beta-galactosidase cDNA. The peptide sequence obtained from the purified Japanese pear beta-galactosidase III matched the deduced amino acid sequence of SVSYDHKAIIINGQKRILISG (amino acid 25-45). Northern blot analysis showed that the probe derived from JP-GAL hybridized to a single 2.6 kb RNA. The mRNA was detected solely in the fruit; none was detected in the buds, leaves, roots or shoots of the Japanese pear. The steady-state level of the beta-galactosidase mRNA was measured during fruit ripening in three cultivars, Housui, Kousui (early ripening) and Niitaka (late ripening). The results showed that regardless of the cultivar, no JP-GAL mRNA was detected in the immature fruit. Increment of the mRNA level with fruit ripening coincided with the increase in the beta-galactosidase III activity. Our results showed that the expression of JP-GAL correlated with fruit softening and JP-GAL may be beta-galactosidase III.
...
PMID:Molecular cloning of beta-galactosidase from Japanese pear (Pyrus pyrifolia) and its gene expression with fruit ripening. 1138 15

Rat intestinal fibroblast lines (F1:G9 and A1:F1) differing in their potential to support intestinal mucosal development were marked with reporter genes to investigate their differentiation potential. The fibroblasts were transfected with plasmids expressing either beta-galactosidase (with or without a nuclear localisation signal) or green fluorescent protein (GFP). Transfection using Tfx50 or Fugene was more efficient than electroporation. The expression of beta-galactosidase was more stable and stronger than GFP. Cells were optimally labelled using the plasmid pL27B-GAL, and sub-clones with a strong and uniform nuclear expression of beta-galactosidase were isolated. These clones expressed beta-galactosidase even after prolonged passage in the absence of selection. The beta-galactosidase tagged lines (F1:G9gal and A1:F1gal) retained the morphological characteristics, viability and differentiation properties of the parental non-transfected lines. In co-culture with a colorectal tumour cell line Caco-2, the F1:G9gal and A1:F1gal cells differed in their morphological organisation but this did not change their expression of smooth muscle alpha-actin.
...
PMID:Differentiation potential of intestinal mesenchyme and its interaction with epithelial cells: a study using beta-galactosidase-expressing fibroblast lines. 1148 98

The mammalian epididymis is an organ particularly rich in acid hydrolases, consistent with a developed lysosomal apparatus. However, some of these enzymes could also play a role in an extracellular environment, since they are actively secreted by the epithelium. In this study the authors measured the activity of five acid hydrolases distributed between the epithelium, fluid, small vesicles, and spermatozoa of the rat cauda epididymis in adult rats, and compared with that distribution under conditions of deprivation of luminal testosterone and testicular compounds (hemicastration). Lysosomal enzymes are differently compartmentalized in rat cauda epididymis. Most of beta-galactosidase (beta-GAL) and aryl sulfatase (approximately 70%) were found in soluble form within the fluid. Some 60% of N-acetyl-beta-D-glucosaminidase (beta-NAG) and alpha-mannosidase (alpha-MAN) become transiently bound to sperm, and beta-glucuronidase (beta-GLU) was mostly concentrated in the epithelium. After remotion of testis this distribution changed, as the retention of alpha-MAN, beta-GAL, beta-GLU, and beta-NAG by the epididiymal tissue increased. The increase of beta-GLU followed an increase of synthesis of the enzyme. The distribution of enzymes in the epididymis from the contralateral side was similar to that in normal rats. The different roles for each enzyme in the epididymis are discussed.
...
PMID:Compartmentalization of lysosomal enzymes in cauda epididymis of normal and castrated rats. 1196 12

In vivo regulation of the LH receptor (LHR) promoter was studied using transgenic (TG) mice harboring fusion genes containing three different lengths of the LHR promoter (7.4 kb, 2.1 kb, and 173 bp), fused with coding sequence of the Escherichia coli beta-galactosidase (beta-GAL) reporter gene. The length of the LHR promoter significantly affected the pattern of beta-GAL expression. In the testis the shortest promoter directed expression primarily of the full-length beta-GAL mRNA, but mainly truncated messages were transcribed from the longer LHR promoter/beta-GAL constructs. The case was reversed in the ovary and adrenal gland. Furthermore, we have recently detected strong LHR expression in the adrenal gland of female mice with chronically elevated serum LH. Therefore, the regulation of the adrenal LHR expression was addressed in the present study using the LHR/beta-GAL TG mice. Elevated LH levels were achieved in the LHR/beta-GAL mice either by gonadectomy or cross-breeding them with TG mice overexpressing a chimeric protein of bovine LH beta-subunit and the C-terminal fragment of human chorionic gonadotropin-beta. In both models, beta-GAL mRNA was found in the adrenal cortex when the 7.4-kb LHR promoter was applied but not in mice carrying the 173-bp LHR promoter. The 7.4-kb construct was activated also in the ovaries in the double TG LHR(beta-GAL)/bovine LH beta-subunit/C-terminal fragment of human chorionic gonadotropin-betamice in some theca-interstitial cells surrounding the follicles. Hence, the LHR promoter elements essential for directing beta-GAL expression to the adrenal gland and ovary (7.4 kb) are different from those recently shown to be essential for the testicular expression (173 bp). In conclusion, elevated serum LH concentrations were found seminal for the LHR promoter activation in the ovaries and adrenals, and different lengths of the promoter are responsible for reporter gene expression in the testis, ovary, and adrenal gland.
...
PMID:Transgenic mice harboring murine luteinizing hormone receptor promoter/beta-galactosidase fusion genes: different structural and hormonal requirements of expression in the testis, ovary, and adrenal gland. 1223 21

For the enhancement of fracture healing, either purified proteins or vectors for expression of growth factors in situ may be used. Adenoviral vectors directly convert cells to express a transgene. However, the cell types which are preferentially infected and the time of expression during fracture healing are currently not known. The adenoviral type 5 vectors used in this study are replication incompetent viruses, one encoding beta-galactosidase (beta-GAL) and one green fluorescent protein. Femora of 35 Sprague-Dawley rats were fractured. Three days after stabilization with Kirschner wire, 10(12) pfu viral suspension were injected into the fracture zone. As a control, five animals received injections of adenovirus type 2. Animals were sacrificed after 3 days, 1, 2 and 4 weeks. Fractures healed radiographically within 2-3 weeks. All specimens were examined for beta-GAL and green fluorescent protein (GFP) expression. Fibroblast and osteoblasts within callus tissue displayed a high transgene expression (week 1). A decrease of expression was observed during the observation period. In this experimental study, we have demonstrated that all cells of the primary callus can be transfected using adenoviral vectors, which provide a tool to further investigate adenoviral transfer of growth factors such as bone morphogenetic protein-2 (BMP-2).
...
PMID:Adenoviral gene transfer in a rat fracture model. 1239 90

We have reported previously that multiple copies of MRG19 suppress GAL genes in a wild-type but not in a gal80 strain of Saccharomyces cerevisiae. In this report we show that disruption of MRG19 leads to a decrease in GAL induction when S. cerevisiae is induced with 0.02% but not with 2.0% galactose. Disruption of MRG19 in a gal3 background (this strain shows long-term adaptation phenotype) further delays the GAL induction, supporting the notion that its function is important only under low inducing signals. As a corollary, disruption of MRG19 in a gal80 strain did not decrease the constitutive expression of GAL genes. These results suggest that MRG19 has a role in GAL regulation only when the induction signal is weak. Unlike the effect on GAL gene expression, disruption of MRG19 leads to de-repression of CYC1-driven beta-galactosidase activity. MRG19 disruptant also showed a twofold increase in the rate of oxygen uptake as compared with the wild-type strain. ADH2, CTA1, DLD1, and CYC7 promoters that are active during nonfermentative growth did not show any de-repression of beta-galactosidase activity in the MRG19 disruptant. Western blot analysis indicated that MRG19 is a glucose repressible gene and is expressed in galactose and glycerol plus lactate. Experiments using green fluorescent protein fusion constructs indicate that Mrg19p is localized in the nucleus consistent with the presence of a consensus nuclear localization signal sequence. Based on the above results, we propose that Mrg19p is a regulator of galactose and nonfermentable carbon utilization.
...
PMID:Molecular characterization of MRG19 of Saccharomyces cerevisiae. Implication in the regulation of galactose and nonfermentable carbon source utilization. 1244 72

A simple generic continuous-flow enzyme immunoassay (CFEIA) for analysis of aminoglycosides in serum has been successfully developed. The developed assay employed a specific monoclonal antibody and beta-galactosidase (beta-GAL) enzyme as label. The assay involves an off-line competitive binding reaction between the analyte and free labelled analyte for the binding sites of the antibody. After equilibrium is reached, the sample was injected into the flow system. The bound antibody complexes with the analyte and the labelled analyte were trapped in a protein G column, while the unbound free labelled analyte was eluted and detected colorimetrically down-stream, after reaction with chlorophenolic red-beta-D-galactopyranoside as a substrate for the beta-GAL enzyme. The concentration of the analyte in a sample was quantified by its ability to inhibit the binding of the analyte-enzyme conjugate to the antibody, and the signal was directly proportional to the concentration of the analyte in the original sample. The optimum conditions for the developed CFEIA were investigated and applied to the analysis of tobramycin, as a representative example of the aminoglycosides, in serum samples. The detection limit of the assay was 0.06 microgml(-1). The assay showed good precision; the coefficients of variation were 2.49-4.33 and 3.30-6.82% for intra- and inter-assay precision, respectively. Serum matrix constituents and the endogenous compounds did not interfere with the assay. Analytical recovery of spiked tobramycin, in the concentration range between 0.5 and 8.0 microgml(-1), was 101.55+/-3.14. The assay results correlated well with those obtained by high-performance liquid chromatography (r=0.991). All the obtained results strongly demonstrate that the developed CFEIA is a suitable method for a rapid and reliable analysis of aminoglycosides in serum.
...
PMID:Development of generic continuous-flow enzyme immunoassay system for analysis of aminoglycosides in serum. 1246 26


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

---